THE HANDPUMP OPTION 11807 l, _~\ - t-~~~~~~~~~~~~~~~~~~~~~~~~~~~c s; ~ ~ ~ ~ ~ P QM .ik rwW A* , ; v*r- S- D , Aj oint contribution by the United Nations Development Programme and the World Bank to the International Drinking Water Supply and Sanitation Decade Community Water Supply: The Handpump Option Rural Water Supply Handpumps Project I,r - ytqAT10or;.'L T°N jUL 0 Y)'1°o- C: > - ; .DVl'V FLOpMENT TC9~~l~cTL~ti.D. 2,0431 A joint contribution by the United Nations Development Programme and the World Bank to the International Drinking Water Supply and Sanitation Decade 198l - 19 Community Water Supply: The Handpump Option Saul Arlosoroff, Gerhard Tschannerl, David Grey, William Journey, Andrew Karp, Otto Langenegger, and Robert Roche The World Bank Washington, D.C. Copyright I 1987 by the International Bank for Reconstruction and Development/THE WORLD BANK 1818 H Street, N.W., Washington, D.C. 20433, U.S.A. All rights reserved Manufactured in the United States of America First printing May 1987 The findings, interpretations, and conclusions expressed in this study are the results of country economic analysis or research supported by the World Bank. They are entirely those of the author(s) and should not be attributed in any manner to the World Bank, to its affiliated organizations, or to members of its Board of Executive Directors or the countries they represent. Any maps that accompany the text have been prepared solely for the convenience of the readers; the designations and presentation of material in them do not imply the expression of any opinion whatsoever on the part of the World Bank, its affiliates, or its Board or member countries conceming the legal status of any country, territory, city, or area, or of the authorities thereof, or concerning the delimitation of its boundaries or its national affiliation. The most recent World Bank publications are described in the annual spring and fall lists. The latest edition is available free of charge from Publications Sales Unit, The World Bank, Washington D.C. 20433, U.S.A. Library of Congress Cataloging-in-Publication Data Community water supply. 1. Hand pumps-Testing. 2. Hand pumps-Developing countries. 3. Water-supply, Rural-Developing countries. I. Arlosoroff, Saul, 1930- TJ903.C65 1986 628.1 44 86-28214 ISBN 0-8213-0850-5 Foreword This document presents the conclusions of five years of work devoted to the assessment of available technology and management options for the wide-scale implementation of community water supply systems. An examination of policy options for developing countries suggests that economic stability and growth can be enhanced if the rural and urban-fringe populations are adequately served with non-polluted water supplies. An adequate water supply is one of the basic needs of life, but is often lacking in developing countries. Not only has the rate of construction of improved water supply systems been slower than the target of complete coverage originally set under the International Drinking Water Supply and Sanitation Decade, but also many of the schemes already completed are not in satisfactory operating condition. A sound investment strategy in this sector calls for low-cost and maintainable solutions to achieve wide-scale coverage of the rural and urban-fringe communities in developing countries. Among the most promising low-cost options are systems based on groundwater and handpumps. Unpolluted groundwater in sufficient quantities for manual extraction can be found in most areas of the world; a handpump is usually the most affordable and hygienic means of lifting the groundwater to the surface. The modern handpump can be maintained by the communities served and manufactured in the developing countries. In the dry regions of the world, handpumps can also be used for livestock watering and micro-irrigation. This conclusion should not prevent the more prosperous communities from acquiring higher levels of service, provided they are institutionally and financially able to provide the necessary operation and maintenance services. For example, they may wish to have a mechanized pumping system, a pipe network or a household yardtap system, all of which reduce the time to fetch water. In executing a community water supply project, these factors must be carefully examined on a case-by-case basis to determine the appropriate type of supply for a particular community. The report summarizes the findings of a project on the testing, and technical and managerial development of handpump-based systems. The project has been carried out jointly by the World Bank and the United Nations Development Programme, and supported by ten donors active in the sector. The report provides guidelines for the selection of the water supply technology and system that best meet the needs of a given community, and gives a detailed assessment of the different types of handpumps tested by the program. It is my hope that this report will be a useful contribution to achieving sustainable and replicable community water supplies throughout the world. S. Shahid Husain A_ _ Vice President, Operations Policy Staff The World Bank v Contents Preface ix Acknowledgments x Executive Summary 1 1. Background 7 Sector Review 7 Technology Choice 8 The Handpumps Project 9 The Reliability Issue 14 Project Impact 14 Future Activities 15 2. Choice of Community Water Supply Technology 19 Technology Options 19 Investment Efficiency 20 Resource Constraints 25 The Right Choice 28 3. Handpump Project Planning and Implementation 31 The Maintenance System 31 The Community 37 The Aquifer 39 The Well 44 The Handpump 45 Finance 45 Summary of Planning Guidelines 47 4. Handpump Technology 49 History of Handpumps 49 Factors Affecting Handpump Performance 52 Handpump Design and Development 57 Standardization 66 Guidelines for VLOM Design 68 5. Pump Selection Guide 71 How to Use the Pump Selection Tables 71 Operating Conditions 72 Data Source 74 Discharge Rate 74 Ease of Maintenance 74 vii Reliability 75 Corrosion Resistance 76 Abrasion Resistance 77 Manufacturing Needs 77 Short List 78 Pump Selection Tables 79 6. Pump Selection: Worked Examples 89 Worked Example No.1: Low Lift 89 Worked Examples Nos. 2 and 3: Intermediate and High Lift 91 Worked Example No.4: VLOM Pumps for Intermediate and High Lift 91 Merit Point Evaluation 91 Handpump Compendium 97 Annex 1 Interesting Pumps Not Tested by the Project 183 Annex 2 Complete List of Pumps Tested 193 Annex 3 Comparison of Costs and Time Savings for CWS Options 195 Bibliography 199 Boxes Box 1.1 Laboratory Testing of Handpumps 9 Box 1.2 Field Testing of Handpumps 11 Box 1.3 The VLOM Concept 13 Box 2.1 Evaluating Technology Options: A Case Study from Thailand 21 Box 2.2 Health Benefits from Water Supply 24 Box 3.1 Village-Level Maintenance in Burkina Faso 33 Box 3.2 Handpump Maintenance: The Three-Tier System in India 34 Box 3.3 Community Involvement in Malawi's Integrated Rural Water Supply 36 Box 3.4 Bangladesh: Motorized Pumping Threatens Suction Handpumps 41 Box 3.5 Some Drilling Methods for Handpump Wells 42 Box 4.1 Handpump Types and Operating Principles 50 Box 4.2 Drawdown in Low-Yield Wells: Examples from West Africa 53 Box 4.3 Corrosion of Downhole Components and the Effects on Water Quality 54 Box 4.4 Effects of Handle Design and Cylinder Size on Pumprod Stresses 58 Box 4.5 Development of Plastic Bearings for Lever Action Handpumps 60 Box 4.6 Case Study of Handpump Development in East Africa 62 Box 4.7 Case Study of Handpump Development in Bangladesh 67 Box 5.1 The Relationship between Handpump Discharge and Pumping Lift 73 Box 5.2 Definitions of Reliability 76 vill "Lasting health and economic benefits for the rural and urban-fringe populations of Africa can be achieved through increased community management of water supply and sanitation systems based on proven low-cost technologies..." All-Africa Seminar on Low-cost Rural and Urban-Fringe Water Supply, Abidjan, Cotedlvoire, October1986. Prefaice The Abidjan statement quoted above reflects a growing designing or making handpumps. Policy makers and consensus among African countries of the political CWS program planners will find guidelines in Chapters 1 commitment and implementation strategies needed to and 2 for selecting the type of water supply system most meet that continent's urgent community water supply appropriate for the financial, technical and institutional (CWS) needs. In Africa, as in the rest of the developing resources available tothe benefitting community. world, the great majority of the rural and urban-fringe Global analysis of needs and resources suggests population lack safe water and proper sanitation. Many that wells equipped with handpumps will be an appro- CWS systems built with foreign aid lie abandoned priate choice for the majority of the 1,800 million low- because they cannot be maintained. Scarcity of capital income people in need of improved supplies in the resources, a shortage of skilled people, and poorly remainder of this century. However, case-by-case developed organizational structures hinder progress. evaluation is needed to ensure that communities with the Fundamental changes of approach are vital if future resources to sustain mechanized pumping schemes offe- programs are to result in sustainable and replicable ring higher service levels are encouraged to obtain them. projects. Evidence from the Project's first five years allows a The International Drinking Water Supply and Sani- measure of confidence that CWS programs designed for tation Decade (IDWSSD) brought attention to the plight community management of maintenance can be of the rural poor. As part of global efforts to bring sustainable and widely replicable, and that handpump improvements, UNDP, the World Bank, and a number of projects can readily form the first step in a progressive major donors have collaborated in projects designed to improvement of service levels. develop and promote low-cost simple technologies which Even in five years of intensive testing, not communities could afford and maintain with their own everything can be measured. To make this document as resources. complete as possible in its advice and recommen- Community Water Supply: The Handpump Option is dations, there have inevitably been points at which data the outcome of one such project. Project INT/81/026 - analysis has had to be supplemented by "best judgment" Laboratory and Field Testing and Technological of experienced Project staff. Wherever possible, such Development of Community Water Supply Handpumps judgments have been drawn to the reader's attention (The Project) - has now completed five years of testing and the basis of the judgment has been explained. and monitoring in 17 countries, involving some 2,700 Throughout its first phase, the Project has been individual pumps of 70 different models. This unique data guided by an Advisory Panel drawn from UN Agencies base, along with data from many more CWS projects, is and collaborating donors. In October 1986, the Advisory the basis for the recommendations in this document, Panel endorsed a program for the next phase (1987- which rounds off the first phase of the Project. 1991). The emphasis will now be on promoting the The wide experience gained and the breadth of data implementation of CWS projects incorporating the collected have justified extension of the findings and principles established during the first phase. Data from recommendations beyond specific guidelines for hand- new projects will be used to continue the analysis of pump selection. It is clear that successful CWS prog- outstanding key issues, such as drilling cost variations, rams need to be planned as a package of measures well design and construction, appropriate community designed to make best use of available resources and to management structures, water quality problems, health ensure that maximum benefits are achieved from benefits, and government support systems for training completed projects. The package includes economic, and spare parts distribution. financial, social and institutional elements as well as Meanwhile, it is clear that the momentum generated technology choice. Above all, success depends on the by the Project will continue to influence governments, sustainability of the CWS system. donors and manufacturers in the selection and provision The Project recommendations are aimed at a wide of appropriate low-cost community water supply audience, beyond those actively involved in buying, systems. lx Acknowledgments Results from the Project for Field and LaboratoryTesting UNDP-assisted projects in WUD - the Low-Cost Sani- and Technological Development of Rural Water Supply tation Project and the Training and Information Project Handpumps (INT/81/026), which are presented in this - for their inspiration and close collaboration. We want document, were obtained with the full collaboration of the to thank our former staff members Leif Rosenhall, Ken many governments with which we have worked over the McLeod, Anthony Ramuglia, Melissa Burns and Nicholas past five years. The Project has been supported by the Burnettfortheircontributions. Division for Interregional and Global Projects (DGIP), The members of the Advisory Panel, particularly United Nations Development Programme (UNDP), and Martin Beyer (UNICEF), its Chairman, have provided the following assistance agencies: Canadian Interna- continuous advice and encouragement. The initiator of tional Development Agency (CIDA); Danish International the Project was John Kalbermatten, whose vision helped Development Agency (DANIDA); Finnish International to shape a number of Decade activities. William Development Agency (FINNIDA); Ministry of Foreign Maschler, former Director of DGIP, UNDP, was instru- Affairs, France; German Ministry for Economic mental in making the Project a reality, and Timothy Cooperation (BMZ) and German Agency for Technical Rothermel, current Director, and Frank Hartvelt, Senior Cooperation (GTZ); Ministry of Foreign Affairs, The Programme Analyst, carry on the active support and Netherlands; Overseas Development Administration participation of DGIP, UNDP. (ODA, UK); Swiss Development Cooperation (SDC); and We extend our gratitude to the managers and staff the Swedish International Development Authority (SIDA). members of the rural water supply projects - nationals The United Nations Volunteers Organization (UNV) in and those from abroad - as well as other profes- Geneva, and the UNDP and UNICEF staff in the project sionals, who have collaborated with the Project. The countries have provided valuable assistance in the material presented in this document is to a large extent a implementation of the Project. Major technical contri- synthesis and analysis of the experience which they butions were made by, among others, the Consumers' gained from many years of dedicated work in the field. Association Testing and Research Laboratories (UK) and This Report would not have been possible without the Swiss Center for Applied Technology (SKAT). the work of our Assistant Regional Project Officers and UNICEF and Crown Agents (UK) have also assisted in monitoring staff in the field: San Shwe Aung, Ramon equipment procurement. Handpump manufacturers in Bisco, Aung Chein, Gerry Clarke, Humberto Cordero, both industrialized and developing countries have been Joe Fonseka, Diawoye Guindo, B.P. Joshi, John Keen, provided with feed-back and responded by improving Eliud Kimaro, Bent Kjellerup, Sampath Kumar, Maria their products. Kyber, Kithsiri Liyanage, Anne Malm, K.M. Minatullah, Many colleagues in the World Bank have contributed Thint Myat, Kyaw Myint, Kyaw Nyunt, Abdallah Syed to the document. Special mention should be made of Osman, Carlos Rodriguez, David Rowsome, Joseph Michael Cohen, Advisor during the main period of Saka, Khin Maung Than, Roland Titus, and M.P. preparation of the document, who closely followed its Vaufreydaz. progress. The economic analysis was prepared by Our warmest thanks go to Brian Appleton, Technical Edward Quicke and Fred Wright, both members of the Writer, who wrote most of this document, based on drafts Project team. The document also draws heavily on work prepared by the Project team. Thanks also go to done by staff in the Water Supply and Urban Develop- Christiane Pogany and Kedar Bryan for assisting in the ment Department (WUD) in the preparation of a sector preparation of the document, and to all the support staff strategy paper for rural water supply, which is still in of the Project in Washington and in the field locations, progress. We are indebted to our colleagues on other without whom this work would not have been possible. Exe? - , ; u e Ive1 mmary An estimated 1,800 million people need improved water individually important, and together forming a complete supplies in the fifteen years to the end of the century, if package for achieving dependable services: developing countries are to reach the target of full coverage. The first half of the International Drinking * Effective involvement of the community in the Water Supply and Sanitation Decade (1981-1990) has design, implementation, maintenance and financing seen increases in the percentages of the rural population of planned improvements, with promoting agencies with access to safe water supplies, but only in Asia has providing technical assistance and support services the pace been quick enough to envisage a target of as needed. The community's needs and wishes essentially full coverage by the end of the century (ten have to be reconciled with its capacity and years later than the original Decade goals). In Africa, willingness to pay for the level of service planned. present progress rates would leave half of the rural population still without safe water in the year 2000, while * Provision for full recurrent cost recovery, with in Latin America, it may be ten years into the next support of capital (construction) costs for poorer century before full coverage is achieved unless progress communities offset by full recovery where higher improves dramatically. service levels are provided. Accelerated progress is hampered by financial and technical resource constraints faced by many Maximum involvement of in-country industry in the developing countries, and the problem is aggravated by supply of services and materials for project the growing number of completed projects which are construction and maintenance (e.g. supply of broken down and abandoned, or functioning much below pumps and spare parts, servicing and repairs), with capacity. Attempts to increase the pace of providing the important proviso that quality control and improved community water supplies have often been reliability should be assured and that costs are frustrated because the technology used has proved competitive. impossible to sustain in village conditions. To make a lasting impact on the urgent needs, * Technology chosen to match the resources community water supply (CWS) strategies must be available to sustain it. based on sustainable and replicable programs, and must take account of the pace at which resource * Institutional and manpower development programs constraints can be overcome. Human resource matching the needs of the planned water supply development programs take time to produce results, and system. institutional changes can only be accomplished gradually. * Parallel programs in health education and sanitation improvements. The Integrated Approach Service Level and Technology Choice Successful CWS programs involve a combination of hardware and software - technology and The decision about the level of service (i.e. the amount institutional/organizational support elements - matched of water provided per capita and the convenience of in such a way that each community recognizes the obtaining it) that a particular community or district should benefits of the improved supply, can afford at least the have involves consideration of many of the issues listed costs of operating and maintaining it, and has the skills, above. The aim is that the technology chosen should spare parts, materials and tools available to sustain it. give the community the highest service level that it is To maximize health benefits, parallel investments in willing to pay for, will benefit from, and has the health education and sanitation programs should be institutional capacity to sustain. planned alongside CWS improvements. Choices may have to be made between surface This "integrated approach" to CWS planning involves water and groundwater as the principal source consideration of a number of key issues, each (sometimes supplemented with rainwater) and then from 1 handpumps, public standpipes, or yardtaps, as the Financial Implications method of distributing the water to the beneficiaries. Costs and benefits will both be linked to the number of Capital costs of the three technologies generally range water points provided, with improved convenience of from US$10-30 per capita for wells equipped with water collection ranking high in the consumers' handpumps to US$30-60 per capita for motorized evaluation of potential benefits. pumping and standpipes and US$60-110 per capita or Groundwater has many advantages over surface more for yardtap services. In global terms, that means water as a source for CWS improvements, the main one that cost estimates for meeting rural water supply needs being that, provided wells are judiciously sited in relation to the year 2000 range from US$50,000 million to to existing or future latrines, safe water should generally US$150,000 million, depending on the choice of be assured without the need for treatment (other technology. advantages are listed in Chapter 2). The resource With the obvious difficulties of mobilizing financial demands of water treatment plants needed to make resources for this scale of investment, rapid progress in supplies from surface water sources safe to drink are meeting basic needs can be achieved only if a large beyond the reach of most communities, and use of proportion of the population in need receives services at untreated surface water frequently represents an the lower end of the cost range. Upgrading to a higher unacceptable health risk. service level may then be financed by the community In cases where an upland catchment can be later, as benefits from the initial investment and from protected against contamination, a gravity-fed system other sources increase available resources. can be reliable and safe, but only a small percentage of Analysis of data from a wide range of CWS projects the population in need of improved supplies live in such indicates a similar divergence in the recurrent (operation areas. It will therefore be rare for CWS programs to be and maintenance) costs of the three options to that based on surface water as the source, and the already noted in the capital costs. With a centralized technology choices analysed in this report are focussed maintenance system, the annual per capita cost of largely on groundwater-based CWS systems. maintenance of a handpump-based CWS system can Assuming that equal system reliability can be range from US$0.50 to US$2.00. Well planned achieved, the three main technology options - community-level maintenance can bring that figure down handpumps, standpipes, and yardtaps - generally as low as US$0.05 per capita per year (see Box 3.1 in represent progressively increasing service levels, and Chapter 3). By comparison, centralized maintenance of a call for increasing financial and technical resources for standpipe system with motorized pumping costs from their implementation and maintenance. The choice of US$2.00 to US$4.00 per capita per year, and for yardtap appropriate technology for a particular project or program maintenance the range is US$4.00 to US$8.00. can only be made when resource constraints have been There are circumstances in which communities may taken into account, including the capability of the users value the time saved due to the extra convenience of to operate and maintain the alternative systems under yardtaps so highly that they are willing and able to pay consideration. the extra price. The analysis method outlined in Annex 3 The theme of reliability recurs throughout this is designed to help identify such communities. More document. In community water supplies, one of the most frequently, the serious shortage of readily available cash important influences on system reliability is the length of resources will mean that recurrent costs must be kept to time for which pumps stand idle when they break down. a minimum, and handpumpswill bethe indicated choice. The response times of centralized maintenance organizations covering dispersed communities can Resource Needs stretch to several months. Box 5.2 in Chapter 5 shows graphically how handpump maintenance carried out by As with financial considerations, comparison of other an area mechanic within a week of breakdown makes a resource demands of the different technologies also pump which breaks down on average every 8 months points to a substantial role for handpump-based systems more "reliable" than one which lasts for an average of 18 in meeting basic human needs. The most significant months before it breaks down, but then must wait two difference between handpump projects and those based months for the mobile maintenance team to arrive. on standpipes or yardtaps, is the switch to motorized In considering the service level to be provided by a pumping, and the consequent need for dependable particular technology, reliability is an important para- energy supplies and skilled pump mechanics, when a meter. Thus a reliable handpump supplying 30 liters per piped distribution system is provided. head per day for 95% of the year, will be providing a In cases where reliable low-cost electric power is higher level of service than yardtaps designed for 150 available from a central grid, an electric pump can be a liters per head per day but working for an average of only relatively inexpensive and operationally simple means of two hours a day because of leakage, breakdown, fuel lifting water. Communities which have the financial and shortages, or limited water available at the intake. technical means available to implement and sustain Comparisons of costs, resource needs, and projects based on electric pumping should be given benefits of the CWS options have to be based on a every encouragement to do so, as this frees scarce realistic assessment of the reliability and sustainability public sector funds and external aid for projects serving of each technology. poorer communities. However, the number of 2 communities with dependable electricity supplies is some of the major obstacles to sustainable water supply presently small - well below 10% of the total rural systems. Now recognized as one of the fundamental population in Africa, only a little higher in most countries principles of handpump design and CWS project in Asia, and reaching 40-50% in China and the more planning, the VLOM concept seeks to avoid the high developed countries of Latin America. cost, long response time, unreliable service and other In the absence of reliable electric power, the alter- operational difficulties in the repair of handpumps native power source for motorized pumps is diesel through central maintenance systems. engines. The logistic problems of ensuring dependable Many past failures of CWS systems can be blamed diesel supplies for dispersed communities have rarely on the inadequacies of central maintenance, in which a been successfully overcome, and there are few exam- water authority dispatches teams of skilled mechanics ples of diesel-powered rural water supply systems oper- with motor vehicles from a base camp, often serving a ating successfully in the long term. The cost of trucking large district, to respond to requests for repairs or to diesel fuel over hundreds of kilometers will usually prove carry out routine maintenance. Instead, maintenance prohibitive. Future developments in solar technology should be a community responsibility, and this in turn may eventually make solar pumping economic for means that the pump design has to be suitable for repair drinking water supplies, but at the moment such by a trained caretaker or area mechanic with basic tools, schemes have very high initial costs and require skilled and that spare parts should be affordable and readily maintenance. Similar conditions apply to windmills. available to the community. The Project strongly Adding the institutional constraints and the severe advocates that pump maintenance responsibilities shortage of skilled mechanics in developing countries, it should be delegated to village committees, and that is clear that systems involving motorized pumping are pumps should be selected with such maintenance in appropriate for only a minority of those in need of new mind. supplies in the coming years. For the rest, it seems clear Developing country governments and donor that drilled or dug wells equipped with handpumps will be agencies are increasingly changing their policies to the appropriate choice. This makes it vitally important include these principles in projects or programs. This is a that handpump-based projects are planned and imple- significant departure from previous practice, particularly mented in ways which will ensure that they perform in Africa, where many different types of unsuitable reliably and can be sustained in the long term and widely pumps have often been brought into a country through replicated. donor assistance. Recipient agencies have thus taken on unmanageable maintenance commitments, which rely The Handpumps Project on public-sector mobile maintenance. In 1981, as one of the activities in support of the Planning and Implementation International Drinking Water Supply and Sanitation Decade (IDWSSD), the United Nations Development Few handpump system failures can be blamed solely on Programme and the World Bank initiated a the pump. Other major causes are: inadequate or global/interregional project for the Laboratory and Field unrealistic provisions for maintenance; poor Testing and Technological Development of Community management, supervision, monitoring and evaluation; Water Supply Handpumps (the Project). The main poor well design or construction, allowing sand to enter objectives have been to promote the development of and damage pumping elements; and the corrosive designs and implementation strategies which will improve effects of groundwater, which are much more extensive the reliability of schemes based on groundwater and than had previously been suspected. handpumps, and which will enable schemes to be Experiences in the field trials and data from many managed by the communities and replicated on a large other CWS projects have enabled the Project to scale. formulate guidelines for the planning and implementation Technology was thought to be at the root of past of CWS projects using wells equipped with handpumps. problems experienced with handpump-based CWS The guidelines, amplified in Chapter 3, deal with six systems, and the Project has carried out laboratory critical elements - the community; the aquifer; well tests in the UK and field trials in 17 countries to measure design and construction; the handpump; the the performance of a total of about 2,700 handpumps. maintenance system; and finance. Field trials lasted at least two years on most pumps, with some 70 different pump models represented in the trials. Community Involvement Test results and conclusions about the performance of each of the pump types still on the market are included in The highest potential for sustainability is achieved when the Handpump Compendium at the end of this document. the community is involved in all phases of the project, In Chapters 5 and 6, the pumps are "rated" for different starting from the planning stage. If the scheme is to operating conditions, and worked examples illustrate continue to operate satisfactorily, people have to different pump selection applications. recognize the need for the improved service, be able and From the beginning, the Project has promoted the willing to pay for the maintenance cost (and eventually concept of VLOM (Village Level Operation and the construction cost), and be willing to manage its Management of Maintenance) as a means of overcoming maintenance. EXECUTIVE SUMMARY 3 Aquifer Analysis found for collecting money, arranging repairs and paying caretakers or mechanics. Initial training of selected Competing demands for other water uses, such as water committee members in simple accounting and irrigation pumping, have to be taken into account when financial management has been effective in a number of evaluating aquifer potential for handpump projects. To countries. The Project is seeking evidence of practical avoid unnecessarily high costs, the well needs to be community-level cost recovery and management mecha- deep enough to allow for seasonal and long-term lowering nisms, to add to those described in Chapter 3. of the water table, but no deeper. Legislation and administrative enforcement are needed in some areas to Today's Handpumps prevent overpumping for irrigation leading to drawdown of the water table and putting existing handpumps out of The standard test procedures used in the laboratory and service. field trials revealed many shortcomings in existing handpump designs. Manufacturers responded well, by Well Design and Construction modifying their products and introducing new models, and there are now many more pumps on the market which Wherever the rock is not fully consolidated, screens and are durable and which allow for substantial involvement filter packs are essential to prevent sand and silt of villagers in pump maintenance. intrusion. Otherwise rapid damage will occur to As a result, in the vast majority of developing commonly-used types of seals and valves. The right countries, it is now possible to design a handpump- choice of drilling equipment, backed by appropriate based water supply system which can be sustained in organization of drilling, can significantly reduce drilling reliable operation without dependence on continual costs and result in more dependable wells. intervention by a central authority. The Project has assisted a number of firms in Handpump Selection developing countries to begin handpump manufacture. Manufacturers from industrialized countries are also A number of factors influence handpump selection, in being encouraged to combine with enterprises in addition to the cost of the pump itself. Among the most developing countries to make pumps under licensing or important are suitability for the intended maintenance joint-venture agreements. In-country manufacture, system (e.g. can it be repaired by a trained pump backed by public or private sector distribution facilities caretaker?), durability, and discharge rate. Pump choice and retail outlets, strongly improves the likelihood that will depend on the required lift and the planned number of spare parts will be available when needed, and facilitates users per pump. Standardization on one or a few pump standardization of pump types in a country to simplify types for any one country can have a significant impact caretaker training and stocking of spare parts. on maintenance and is an important selection criterion; Encouraging as these developments are, there and corrosion resistance has to be taken into account remains a scarcity of handpump models which can be when groundwater is aggressive. described as VLOM and are suitable for lifting from The Project has prepared Draft Sample Bidding depths of more than about 25 meters (though the Documents for handpump procurement, to assist majority of the population in need lives in regions where governments and support agencies to take account of the water table is not so deep). The heavy weight of important pump characteristics when purchasing pumps downhole components makes extraction of the complete through international competitive bidding. assembly from deep wells difficult. An added problem is that handpumps deliver less water when pumping from Community Management of Maintenance greater depths. The pumps are therefore heavily used and so suffer rapid wear - a problem which is Under the system recommended by the Project, the aggravated by the tendency for deep wells to serve more community organizes and finances all repair and routine people per well, in order to spread the higher costs of the maintenance of the handpump. Work is carried out either well and pump over a larger number of users. by a designated community member with minimal training For low lifts (up to about 12 meters), direct action and basic tools, or by an area mechanic (usually with a pumps, like the Tara prototype developed in Bangladesh, bicycle or moped) covering a number of pumps. The in which the operator lifts and lowers a T-bar handle public authority has an important role to play in the directly attached to the pumprods, have a number of training of caretakers and mechanics, and the advantages. Elimination of the bearings that are part of organization of an adequate spare parts distribution lever or flywheel-operated pumps reduces maintenance system, but should then hand over maintenance of the needs, and the pumps can be manufactured in scheme to the beneficiaries. developing countries at a relatively low cost. They make extensive use of plastics materials, which make the Financial Management pumps light in weight and corrosion resistant. Direct action pumps have the great advantages over suction Even when the community is willing to pay for and pumps that they can lift from more than the 7-meter limit manage the upkeep of its water supply system, the for suction (important since groundwater levels are scheme may founder unless a suitable mechanism is falling in many parts of the world) and that they do not 4 need priming and therefore avoid the risk of and the available field and laboratory evidence. A contaminating the well by pouring in polluted water. methodology is suggested for using the ratings to For high lifts (down to about 45 meters), a below- compile a short list of acceptable pumps for a project or ground design which allows extraction of the piston (and program, and some worked examples illustrate appli- footvalve if desired) without removal of the cylinder and cation of the selection procedures in specific cases. It is rising main appears to be the most promising VLOM clear from the worked examples that some pumps are design. However, only a very few low-cost, durable and much more suited than others to conditions in developing corrosion-resistant VLOM designs for below-ground countries, and that as pumping lift increases, the number components have been used successfully in preliminary of pumps suitable for village-level maintenance declines tests for lifts between 25 and 45 meters. Development of rapidly. more VLOM pumps for use beyond 25 meters remains an important task for the next phase of the Project- Future Tasks and for manufacturers and implementing agencies. To take standardization further, attempts are now Implementation will be the central emphasis of the being made to develop designs in which some of the Project's second phase (1987-91). In their collaboration same components can be used for pumps designed for with governments and donors, Project staff will urge different depth ranges. In East African development inclusion of the "systems approach" in CWS programs. work, for example, a standard 50mm-diameter cylinder Every opportunity will be taken to collect data, with the same plunger, footvalve and pumprod is being demonstrate successful approaches, and develop det- tested with different pumphead configurations for the ailed implementation guidelines on the critical elements whole range of lifts from 0 to 45 meters. For low lifts, the identified in the first phase: drilling technology and well below-ground components are connected to a T-bar design; community participation; training at all levels; in- handle to be operated as a direct action pump; at higher country manufacture, standardization and spare parts lifts, a lever handle is used, with the handle length distribution; corrosion and water quality; complemen- varying (two options) depending on the lift. tarity of water supply, sanitation and health education; In Chapters 5 and 6, the monitoring results and evaluation of benefits and selection of service levels; experiences of Project staff and others have been used and non-domestic uses of groundwater. to "rate" each of the 42 handpumps tested by the Project Governments and donors have an important part to which are still on the market, under a series of design play, by committing resources to the implementation of criteria which may influence pump selection. The criteria low-cost CWS programs and by sharing experiences, so will not always match precisely conditions under which that lessons can be learned and model strategies deve- particular pumps have been tested in the field, and in loped for each element of the CWS package. Technical assessing pump performance over a range of conditions, assistance will be made available wherever possible, to Project staff have frequently had to make "best- support activities aimed at furthering community manage- judgment" decisions on the basis of their own experience ment of low-cost water supply and sanitation systems. EXECUTIVE SUMMARY 5 Chapter 1 Background Sector Review century. To maintain this goal, however, the commitment to constructing additional community water supply When the member governments of the United Nations systems must remain strong, and the systems installed proclaimed the 1 980s to be the International Drinking up to now must be properly maintained. Water Supply and Sanitation Decade (the Water In Africa, the prognosis is less good. Provision of Decade), they were responding to an urgent need. An improved rural water supplies (for 10 million people per estimated 30,000 people were dying every day, many of year) has just kept pace with the population growth rate. them from diseases attributable to a lack of safe water or At that rate, no more than half of the rural population will adequate sanitation facilities. In 1980, the World Health have an adequate water supply by the end of the Organization estimated that more than 70% of the century. world's rural population was without access to a safe and In Latin America and the Caribbean, rural water adequate water supply; some 1,150 million villagers supply services were provided at a rate of three million (China's statistics were not then available) were drinking people served per year, or twice the population growth waterwhichwasathreattotheirhealth. rate. If the same pace was maintained, it would be well The Water Decade is more than half over, and while into the next century before the region approached full much has been accomplished in rural water supply, the coverage. There is a strong need for increased efforts in large amount which still remains to be done re- both Africa and Latin America. emphasizes the urgent need to find sustainable and If the Water Decade's aim of bringing safe water to replicable ways of bringing clean water to rural and urban- all by 1990 is deferred to the end of the century, and fringe communities. account is taken of the progress made up to mid- Statistics on the first three years of the Decade Decade, the number of people to be served in the fifteen (Table 1.1) show that progress has been achieved in all years to the year 2000 is now estimated to be 1,800 the regions. The progress in building new rural water million, including 400 million in China. supplies has been greatest in Asia. About 70 million The magnitude of the task is daunting, particularly people a year obtained improved water supplies in the when seen against the background of severe financial rural areas of Asia and the Pacific in the first three years and technical resource constraints which faces so many of the Decade, while the rural population grew by 15 developing countries. And even if such a rapid million per year. If this trend were to continue, the region construction and investment schedule is possible, what would reach essentially full coverage by the end of the chance is there of new systems being kept in working Table 1.1 Water Supply Coverage 1980-1983 RURAL URBAN Totalpopulation Population served Totalpopulation Population served (millions) 1980 1983 (millions) 1980 1983 Region 1980 1983 mill. % mill. % 1980 1983 mill % mill. % Africa 334 356 73 22 103 29 135 160 89 66 91 57 Asia/Pacific 1064 1109 277 26 488 44 428 493 278 65 330 67 Latin Amerca 124 126 52 42 62 49 234 254 183 78 216 85 Source: Reportof the Secretary Generalof the United Nations to the Economic andSocial Councilof the UN GeneralAssembly - Progress in the Attainment of the Goals of the International Drinking Water Supply and Sanitation Decade. A/40/108, March 1985. 7 -S , ~T~ be imposed on communities which want and can afford .4.t ' higher service levels. :,; 1j,.,* Mobilization of local cash resources may provide additional funds where the community has a strong desire for a higher level of service and the technical capacity is available to maintain such a service. A successful approach in these higher income areas involves creation of institutional mechanisms, often -w- 4;<= --( through the private sector, by which people can obtain ^- -- X the type of water system they want and are able and willing to pay for. w:-_ , z N In Brazil and Kenya, among other countries, credit : banks have established revolving funds to assist - 1 .1 - M communities in the financing of new CWS projects, using ~. j > =_ revenue collected from existing schemes. In some cases, the funds are linked to other revenue earning An abandoned pump means wasted investment. Proper planning activities, such as agricultural production, and loans will ensure that adequate resources are available for main- may also be used for construction of schools, health tenanceandrepair, beforetheCWStechnologyischosen. centers, etc. One important reason why CWS coverage is presently so low is that many newly built water supply order, when many existing installations are already systems have fallen rapidly into disrepair and been broken down or abandoned? abandoned by communities unable to keep them Yet the case for providing improved water supplies functioning. Skills and equipment are in short supply in is compelling. Improved health, increased agricultural the poor areas of most developing countries, and production and accelerated village development bring technology choice has to be based on the capacity of economic and social benefits, to add to the powerful the benefitting community or the implementing agency to humanitarian arguments for reducing the toll of death operate and maintain the completed system at an and debilitating disease resulting from present insanitary affordable cost. conditions. The challenge for all developing countries, Most communities do not have either the skills or the and for aid agencies seeking to assist them, is to devise organizational capacity to maintain motorized pumps. a CWS strategy which matches the services provided Centralized maintenance, which depends on a mobile with the resources available to sustain them - and to team of skilled mechanics traveling to repair breakdowns implement that strategy quickly and effectively. A prime in motor vehicles, has proved to be expensive and objective of this document is to set out the essential unreliable on all types of water supplies, including elements of such a strategy. handpumps. Handpump systems enable simpler main- tenance arrangements to be established. Technology Choice More successful projects typically involve hand- pumps selected to be maintainable at the village level by Capital costs of efficiently built CWS projects generally a local caretaker equipped with basic tools, or by an area range from US$10-30 per capita for groundwater mechanic. The operation and maintenance demands of schemes based on handpumps, US$30-60 per capita for motorized pumping systems are greater, and it is vital standpipe supplies, and US$60-1 10 per capita for yard- that the community should have access to reliable fuel tap services. In global terms, that means a difference in supplies and to the necessary skills and equipment for cost estimates for meeting water supply needs to the upkeep of the system, before a decision is taken to year 2000 of as much as US$75-1 00,000 million, depen- implement a CWS project based on motorized pumps. ding on the choice of technology. It is clear that most of For communities connected to a dependable electric the population in need of improved supplies will have to grid, an electric submersible pump feeding standpipes or be provided initially with low-cost solutions, for financial yardtaps from an elevated tank can give a reliable reasons alone. supply, providing that skilled pump mechanics are on Upgrading to a potentially higher service level - e.g. by fitting motorized pumps on high-yielding wells initially equipped with handpumps and adding a piped "It is clear that most of the distribution system and standpipes - may eventually population in need of improved follow, as the community realizes the benefits of an improved supply and is able to finance further supplies will have to be improvements from its own resources. Immediate provided initially with low-cost implementation of higher service levels can really only solut in inial reasos be justified if all, or at least most, of the capital and solutions, for financial reasons recurrent costs are contributed by the community. This alone." does not mean, however, that low-cost options should 8 Box 1.1 Laboratory Testing of Handpumps A standard procedure for testing handpumps has inspected on delivery and packing, assembly, been developed by Consumers' Association Testing condition of parts and quality of installation and Research (CATR) Laboratories in the UK, and instructions are assessed. Measurements are taken some 40 types of handpumps have been tested to of volume flow, work input, mechanical efficiency, and date. footvalve leakage, at three water depths and three While laboratory testing cannot fully replicate stroke speeds. Reactions to pump operation are pump operation in the field, it can provide valuable obtained from different types of users (men, women comparative information in a relatively short period of and children), and the results of their performance time. Manufacturers can thus obtain an early assess- with each pump are recorded. An engineering ment of potential problems, before the pump is assessment includes evaluation of suitability for subjected to the more costly and time-consuming manufacture in developing countries, ease of stage of field testing. The controlled conditions of installation, maintenance and repair, resistance to laboratory testing also ensure that direct comp- contamination or abuse, potential safety hazards, arisons can be made between the performance of and suggested design improvements. different pumps. A brief verdict on the test results and an overall In the laboratory tests, each pump is subjected assessment of the pump is communicated to the to a 4,000 hour endurance test - 2,000 hours of manufacturer for comment. Full descriptions of the pumping clean hard water, followed by 2,000 hours in tests carried out and the assessments resulting from which a controlled concentration of abrasive them have been reported in Project Reports 1-4 and materials is added. Pumps are mechanically driven at World Bank Applied Technology Note No. 2. Report 4 40 strokes per minute, or the speed most appropriate (World Bank Technical Paper 29) also contains full to the pump design, with a simulated pumping head details of the test procedures. representing the manufacturer's recommended Laboratory test results have been used, and pumping limit. The full test corresponds to about 2 combined with field trial information where available, years of use in the field at an average 6 hours per to develop the pump ratings in the Pump Selection day. Guide (Chapter 5), and to prepare the individual pump Before endurance testing, each pump is entries in the Handpump Compendium. The Handpumps Project hand when repairs are needed, and an organization exists to collect charges and pay for repairs. Diesel Recognition of the important role that handpumps would pumps have a poor performance record in community have to play in meeting Water Decade objectives water supplies, principally because of the logistical prompted UNDP and the World Bank to initiate the Inter- difficulties in many developing countries of guaranteeing regional Project for Laboratory and Field Testing and fuel supplies to remote areas and the mechanical skills Technological Development of Handpumps for and spare parts needed to keep the pumps in working Community Water Supply (the Project) in 1981. order. Sponsored by UNDP, executed by the World Bank, and Regardless of the technology chosen, people will co-funded by a number of other agencies, the Project operate and maintain an improved water supply only if now has a program of activities extending to 1991. they value it. It must provide an appreciable improve- The initial aims were focussed mainly on hardware. ment over existing traditional sources (greater conve- Many of the handpumps then being used to supply as nience, better water quality); it must be well designed many as 500 villagers per pump in developing countries (sufficient pumps for the community population to avoid were little altered from the household pumps which long queues); and water points must be sited in served individual European and American families more consultation with the community. than half a century ago. The combination of financial, technical and insti- The large majority of handpumps in use in tutional constraints and the severe shortage of skilled developing countries today are suction pumps serving manpower in developing countries, mean that systems only one or a few families. There are several million in involving motorized pumping will be beyond the reach of use in China, over a million in Bangladesh, and hundreds the large majority of those in need of new supplies by the of thousands in other Asian countries. These pumps, year 2000. For them, wells equipped with handpumps will even though they have serious drawbacks, as explained be a first step. Guidelines to identify communities for in Box 4.1 in Chapter 4, are cheaply produced by local which handpumps will be the right option and those for manufacturers, are durable enough for their light use, which a higher service level is more appropriate are the and can easily be maintained by the users. The Project subject of Chapter 2. has therefore addressed itself to the more serious BACKGROUND 9 FIELD TRIALS AND NUMBER OF PUMPS TESTED ~~~~_ C _p. - 'r___. t ,. t_., j J c t' < >- 5 ~~~~~CHINA ' BANGLADESH 5/k~~~35O) ~ (160) S PHILIPPINES BURKINA FA N - HI,P (24o) (80) C, COTE D'IVOIRE YA (120) PAPUA 2 2 (55) t T ( \' ? NEW GUINEA \ t , (3801 FGHANA- NIA 1160) (60) (380) \< | > 2' ( 4-LAWI 1~~~ ~ ~ ~~~~~225) + UIA (220) - |IIIIhIIIIIIIJ |PROJECT COUNTRIES * FIELD TRIALS EQUATORIAL SCALE 1) ~~~~~50)) (80) NUMBER OF TESTED PUMPS I! I_ _ KILOMETERS Box 1.2 Field Testing of Handpumps By mid-1986, the Project had monitored the of 70 pump types tested are reduced to a total of 42 performance of some 2,700 handpumps in 17 individual entries because some are no longer manu- countries - eight in Africa, eight in Asia, and one in factured and others have been grouped with similar Latin America (see map opposite). Most field trials designs by other manufacturers. have had a minimum duration of two years, during Pumps were visited, inspected, and repaired as which a full-time Country Monitoring Engineer (CME) necessary, at intervals of one to three months, - usually a United Nations Volunteer - participated enabling the CMEs to keep track of user reaction, in the installation and maintenance, and monitored repair difficulties, robustness, and resistance to the performance of all pumps in each field trial. damage from abrasion or corrosion. The monitoring To be included in the field trials, a handpump had was not fully representative of actual operation in a to meet one or more of three criteria: typical community water supply, in the sense that maintenance and repair interventions were coordin- * The pump type was in widespread use in devel- ated by the CMEs, so that the maintenance system oping countries. was a combination of village participation and central management (Maintenance Systems A and C as * It was commonly used in the country of the field defined in Chapter 5). However, efforts were made, in trial. collaboration with the implementing agencies, to expand the scope and quality of village participation * It was judged by the Project to have VLOM as the field trials progressed. potential. Data from the forms were analyzed periodically by the CME and compiled in quarterly reports for the In all, some 70 different pump types were tested, information and comment of the Project staff and and it was thought that a minimum of 20 units of each agencies collaborating in the particular field trial. The type would be needed to ensure statistical validity of Regional Project Officers made frequent visits to each the results. In fact, an average of about 40 units of field trial area in their regions, to assess progress and each pump type were installed, but it turned out that results with the CME. only small numbers were needed to demonstrate the As the field trials progressed, some manufac- difficulty of repairing some pumps, while some turers modified their pumps, in response to infor- performed so poorly as to be totally unacceptable to mation from the Project about problems identified in the users or implementing agency and monitoring was the laboratory or the field. If the Project staff judged discontinued. that the modifications had potential for improving the The Project prepared standard monitoring forms field performance, modified components were retro- for use in all countries, to make data comparable. The fitted into the pumps being monitored, or in a few forms record well and pump characteristics, site cases replacement pumps were installed and inspection details, repair and maintenance inter- monitoring began again. ventions, social and cultural factors, and cost data This clearly meant that the new installations were (copies of the forms are contained in Annex E of monitored for a shorter period than the unmodified Project Report 4 - Handpumps Testing and pumps, and complicated comparison of the results. In Development: Progress Report on Field and presenting the results in this report, Project engineers Laboratory Testing - World Bank Technical Paper closely involved in the installation and evaluation of 29). In particular, each breakdown repair report the pumps have sometimes had to apply "best includes details of the reason for the breakdown, the judgment" in an attempt to make all the assessments type of repair needed, the amount of time taken, compatible. equipment used, etc, along with descriptions of parts In addition to the unique comparative data replaced and their cost. collected on handpump technology, Project personnel In a few cases where the same pump type is have been well placed to evaluate other factors which produced by more than one manufacturer, each can affect handpump performance. As Chapters 3 and manufacturer's pump has been evaluated separately, 4 emphasize, field trial experience has amply to cover potential differences in production quality demonstrated that, while a suitable pump is a critical control or design modifications. Any variations in per- ingredient for a successful water supply, other formance between different manufacturers' versions ingredients are also vital, among them: proper well of the same pump model are noted in the Handpump design and construction; proper pump installation; Compendium at the end of this report, where the total and proper planning of operation and maintenance. BACKGROUND 11 program. In all, some 40 pump models have been subjected to endurance tests, designed to reveal their -[> ir s XD durability and the frequency of maintenance or repair needed. The laboratory trials also involved other tests, to assess the suitability of pumps for manufacture, operation and maintenance in developing countries (see Box 1 .1). Results were reported to the mnanufacturers as the need arose during testing, and Project Reports 1 to 4, which include details of the CATR findings, were circulated to a wide audience in the CWS sector. The aim, achieved in many instances, was to encourage improvements to existing handpump models alongside - f s w - ¢ e L-1 Z the formulation of guidelines for new designs. The laboratory results provide a useful quick guide l'I i_ito a pump's likely long-term performance, but they Some 40 types of handpumps have been tested so far in cannot fully simulate the conditions under which a specially built test tower at the CATR Laboratory in the handpumps must operate in developing countries. The UK. Project has therefore undertaken an extensive program of field testing of handpumps, creating a unique data problem of pumps for use by more than about 50 people. base on the performance of most pumps in common use Based on the supposition that high failure rates on for community water supplies. A total of 2,700 individual past handpump projects were caused by inadequate handpumps have been monitored in trials covering 17 pump designs, the Project set out to evaluate the major countries and spanning over two years of actual handpump types then on the market, to cooperate with operation. Again, results have been shared with researchers and manufacturers in the development of manufacturers, participating governments and donor design improvements, and in new designs, and to organizations, and feedback has played an important produce guidelines to assist developing countries in the part in the data gathering and analysis of field trial selection of appropriate pumps for specific applications. results. Box 1.2 describes the methodology of the field While these initial objectives have remained at the trials. core of the program, the focus has widened The initial intention to develop a new generation of considerably, as it became clear from the early findings handpumps specifically designed to be durable when that handpump technology, though clearly important, used in developing countries was only part of the was only one of several interdependent factors solution to performance problems on handpump influencing the success or failure of community water projects. The field trials confirmed that, as Paceyl and supply projects. Other critical elements were identified, others had written, maintenance difficulties often arose such as: the planning and organization of handpump more from institutional or financial shortcomings than maintenance; the design and construction of wells; and from technical difficulties with the pumps themselves. the capacity and willingness of the community to pay for Pumps had been remaining idle because mechanics, the upkeep of the completed system. Crucial elements in the evolution of the Project and in the formulation of conclusions and recommendations if have been the rapid and widespread dissemination of ...maintenance difficulties results and conclusions, and the feedback obtained often arose more from from collaborating governments, donor agencies, and institutional or financial manufacturers. The wide scope of the Project has made it vital that as many people as possible were kept shortcomings than from informed about its activities and about the concepts technical difficulties with the being developed. The Project methodology therefore includes provision for regular contacts among those pumps themselves." directly involved in Project activities, workshops to exchange experiences and ideas with others involved in the sector, and many individual contacts with handpump tools or spare parts were not readily available, or manufacturers. because there were no funds to pay for the expensive The Project began with laboratory testing of the central maintenance teams to travel long distances to most commonly used handpumps in a purpose-built test carry out individual repairs. And many pumps were failing rig at the Consumers' Association Testing and Research because of poor well construction, allowing large (CATR) Laboratories in Harpenden, England. CATR had previously tested 12 handpumps in a program sponsored 1. Pacey, Arnold. 'Technology is Not Enough: The Provision by the Overseas Development Administration (UK), and and Maintenance of Appropriate Water Supplies." Aqua 1 these results provided a basis for the Project test (1977):1-58 12 Box 1.3 The VLOM Concept An early conclusion of the Project was that strong be motivated. Recognizing that central maintenance involvement of the user community in maintenance cannot be dispensed with overnight, the Project has was essential for successful projects. The Project also encouraged manufacturers to improve the coined the term VLOM - Village Level Operation durability of existing pumps, to lengthen the interval and Maintenance - as a means of bringing home to between repairs. handpump manufacturers and users the key issue in The VLOM principles were well received. solving widespread problems experienced with Manufacturers quickly responded to reliability centralized maintenance. problems identified in laboratory and field testing, and Experience in one country after another has worked to develop pumps which can be more easily shown that a central maintenance system, requiring a repaired by handpump caretakers or local mechanics. motor vehicle and crew to move out from a base At the same time, planners and promoters of hand- camp, is unable to keep pumps in satisfactory pump schemes began to pass on responsibilities for operating condition. The large expense of such maintenance to the pump users, selecting pumps maintenance and the logistical and staffing needs to accordingly and introducing training courses for pump supply enough experienced and motivated teams of caretakers and area mechanics. As project exper- mechanics to carry out repairs promptly have proved ience has grown, and donors and implementing very difficult to sustain. But the desirable alternative agencies have experimented with better ways to of village-level maintenance is only feasible if the design projects, alternative maintenance systems pump design allows for it. have been assessed, and it has become clear that Initially, the VLOM concept was applied only to different models work best in different circumstances. the hardware, the aim being to develop pumps This has led to an extension of the VLOM concept specifically designed to be: into software, or organizational matters. A common feature of successful handpump * Easily maintained by a villager caretaker, requ- projects is the emphasis on village management of iring minimal skills and few tools; maintenance, reducing the dependence on central government support of essential functions. In the * Manufactured in-country, primarily to ensure the extended VLOM concept, where M means availability of spare parts; Management of maintenance, these elements have been added: * Robust and reliable under field conditions; and * Community choice of when to service pumps; * Cost effective. * Community choice of who will service pumps; When the Project started, pumps meeting these and needs for lifts of more than 7 meters were not readily available on the market, and their development had to * Direct payment to repairers by the community. quantities of sand to reach the pumping elements. term - VLOM - for Village Level Operation and Once these critical issues became clear, the scope Maintenance, which has been closely associated with of the project was extended. Data has been collected the Project since 1981 and is now widely used by from the field trials and from as many other CWS projects planners and manufacturers alike. The VLOM concept as possible, which would enable conclusions to be drawn includes the development of handpumps specifically about all the key elements of a handpump-based CWS designed to be maintained by village caretakers, but system. Many of these conclusions are relevant to other also extends into the institutional arrangements needed CWS technologies as well as handpumps, as will become to ensure that skills, tools and spare parts are available apparent in Chapter 2. when needed (see Box 1.3). The term VLOM has New concepts were developed, as the defects of therefore been expanded to mean Village Level existing systems became apparent. Data from a number Management of Maintenance (see Box 1.3). of different countries showed that a major cost element Promotion of the VLOM concept through in pump maintenance was transport, and the Project workshops, press articles and individual or group began to look for ways of reducing the need for discussions became another element in the Project expensive mobile teams. It was clear that greater program, and spawned additional activities alongside the involvement of the community itself in maintenance monitoring of field trials. To assist the development of would bring both lower costs and better reliability. pumps suitable for village-level maintenance, Project This very early conclusion led to the coining of a new staff have collaborated with existing manufacturers in BACKGROUND 13 the formulation of new designs. In addition, the Project laboratory field trials or by experiences on other projects has provided technical assistance to a number of have been brought to the attention of the Project's wide manufacturers in developing countries stimulating audience as quickly as possible. In this way, it has been improvements to existing designs and developing quality possible to ensure that changes in technological or control procedures. institutional approaches could be implemented quickly, Developing country governments have been given without waiting for detailed analyses to be published in a technical assistance in the planning and implementation final report. It is encouraging to note ways in which of handpump projects based on VLOM principles, and preliminary findings from the Project have influenced feedback from planners and designers is being recent developments in the CWS sector. incorporated in model maintenance systems developed by the Project for future field demonstration and testing. * Aware of a large potential market for suitable pumps, As the field trials were coming to an end, results and manufacturers have responded quickly to test preliminary conclusions were submitted to the results, seeking to produce improved pumps, or collaborating agencies, and their reactions too are being even to undertake complete re-design. While some incorporated in the Project recommendations for future manufacturers withdrew pumps from the market activities. after they performed poorly in laboratory or field In the course of the field trials, a number of issues trials, many chose to make changes and have been have arisen which have special importance on particular very willing to submit their new designs to the projects, and which local Project staff have investigated rigorous scrutiny of Project testing. One result is in some detail. Their findings will need further study that recent projects in West Africa, using before general conclusions can be drawn, but the data international procurement procedures, have collected has already provided some solutions for attracted a large number of qualifying bids, a pressing local problems. Among these special studies reflection of both increased interest in the sector are: links between water supply, sanitation, and health and more pump models which meet performance and improvements (e.g. Bangladesh); corrosion and durability requirements. The Project has published groundwater quality (e.g. Ghana); and well construction Draft Sample Bidding Documents for the techniques (e.g. Kenya and China). procurement of handpumps by international competitive bidding. The Reliability Issue To accelerate the introduction of design changes In comparing the performance of different handpumps in needed to produce true VLOM pumps, Project staff the field trials, it has become apparent that the have been collaborating with manufacturers and conventional interpretaion of "reliability", based on the research organizations in developing countries. Mean Time Before Failure (MTBF), is inappropriate. The Local manufacture of handpumps is growing rapidly critical item is the period of time for which many pumps in many countries, with joint ventures and licensing stand idle while waiting to be repaired. The Project has arrangements also making some existing pumps therefore adopted a definition of Reliability which in the more suitable for VLOM. There is still a shortage of mechanical engineering industry would refer to pumps which meet VLOM requirements and are Availability, i.e. capable of pumping from depths beyond 25 meters, but several prototypes have performed well in Reliability is the probability that the pump is preliminary field tests and there are grounds for in operating condition on any one day, optimism that choice will be less restricted in the calculated as the sum of the operating time near future. The new prototypes make substantial before failure divided by the total time. use of plastics for below-ground components and for long-lasting easily-replaceable plastic bearings With this definition, it is clear, as Box 5.2 in Chapter which are also light and cheap (see Chapter 4). 5 shows graphically, that a pump which breaks down on average after 18 months of operation, but then stands * By identifying weak elements in past handpump idle for two months each time, waiting for the mobile schemes, the Project was instrumental in creating maintenance team to arrive, is less reliable than one an awareness among donors and implementing which breaks down after 8 months, but is repaired within agencies that pump selection and planning of a week by an area mechanic. maintenance are critical to long-term success. This This concept of reliability is crucial in comparing is beginning to lead to a tightening of pump CWS technologies. The response time of maintenance specifications, and a recognition that a policy of tied organizations is critical, and reliability can only be aid involving pumps from the donor country is assessed when the characteristics of the technology ultimately counter-productive, because failure of the and the institutional support are taken into account. pump jeopardizes the much larger investment in the well. Project Impact Donors now increasingly monitor handpump perfor- mance on their own projects, and are assisting with Throughout the Project, issues brought to light by in-country manufacture of the most suitable hand- 14 pumps. Apart from its added development impact, the donors find that avoiding tied aid for handpumps significantly reduces the extra commitment that they have had to make in the past to continued - ______ financial and manpower support for operation and maintenance of imported pumps. Probably the most significant impact of the Project to date, however, has been the widespread recognition that management of systems once they are installed must be a community responsibility, _ and that community participation must start at the planning stage. When that recognition is translated into establishment of village-based organizations to look after completed projects, dramatic improve- ments can be expected in the reliability of handpump- The potential of handpumps for micro-irrigation is largely based schemes (India has already shown what can unexplored. be achieved in a short time, by reducing the failure rate of village handpumps from about 70% in the mid- 70s to about 20% today, with further improvements anticipated as more design modifications are made widespread implementation of low-cost CWS programs. to the standard India Mark II in line with VLOM Within projects designed to take advantage of the criteria). present state of knowledge, studies will continue into issues which can be expected to lead to additional * Sand pumping was found to be a major cause of improvement in the effectiveness of future programs. handpump failure in the field trials - affecting even Among the issues to be addressed in this second phase those pumps which had performed well in the are: laboratory tests. Damage to leather cup seals was the main cause of breakdown, and new designs of * Community financing and management, including nitrile rubber seals are now being tested for a the role of women. number of pumps, with encouraging results. At the same time, the Project has demonstrated in East * Cost-effective drilling, well design, construction and Africa the dramatic impact on pump performance of development. improved well design and construction. The same techniques are now being introduced in other field * FurtherdevelopmentofVLOM handpumps. trial areas with sand pumping problems. * Human resources development at all levels in the * An important result of the field trials in West Africa public and private sectors. was the extent of rising main, pumprod and other component failures caused by corrosion (as many * Establishment of maintenance systems, including as 60% of the failures in the southern Ghana field selection, training and payment of caretakers. trials were directly attributed to corrosive well water, and galvanizing offered little protection - see Box * Project design criteria, including choice of service 4.3 in Chapter 4). The findings have been combined level. with data from other agencies, and revealed that corrosive groundwater is much more widespread and In-country manufacture of pumps, including quality much more damaging than previously suspected, in control procedures and spare parts supply and both Africa and Asia. Further work is planned on this distribution. important problem. * Solutions to water quality-related problems, Future Activities especially corrosion. The first phase of the Project, during which primary * Sanitation and health education components. emphasis was placed on the improvement of pump technology, is drawing to a close. Worldwide experience * Non-domestic water uses, such as micro-irrigation with CWS projects has established the essential and cattle watering. elements of sustainable and replicable CWS systems. The Project emphasis is now switching to imple- Governments and aid agencies will be offered mentation. Through technical assistance in project assistance in selecting the most suitable pumps for preparation, and collaboration in activities incorporating each country or region, in institutional aspects of the concepts of community management and public system management, and in ways to introduce a policy agency support, the Project will be actively promoting BACKGROUND 15 of standardization to maintain an uninterrupted supply of The Project has already demonstrated that CWS spare parts. The technical assistance already being systems perform best when the community is involved in provided in some countries for manufacture is to be each stage of project planning, construction and main- extended to include advice on pre-selection of designs tenance, and when proper training has been provided for and strengthening of internal and external quality control pump caretakers and mechanics. Future projects will procedures. From manufacture, the process will be include measures to involve the community from the taken through, as needed, to distribution, with the beginning, and will give special emphasis to the potential establishment of networks of spare parts outlets, role of women as pump caretakers where appropriate, ultimately handled by the private sector. and to cost recovery, contracting of maintenance staff, The key issue of drilled-well design and construction and involvement of the private sector. is to be tackled by an investigation of the reasons for A crucial aspect of the Project's next phase will be high well costs in Africa and guidelines on design and its collaboration with developing country institutions, to construction techniques. Wherever possible, new assist in building up their capacity to provide the projects will serve as venues for establishing efficient necessary guidance and support in the long term, and to drilling processes and bringing down costs. extend and replicate successful projects. This will The advantages of handpumps for rural domestic involve the creation of action plans for institutional deve- water supply are now clearly established, but limited lopment, training, research and testing. attention has yet been given to the potential use of The scope of future Project activities was recently handpumps for micro-irrigation. Small-plot irrigation approved by its Advisory Panel. Core funding has been offers both subsistence and cash earnings in parts of assured by UNDP, and several bilateral aid agencies are Africa and elsewhere, but is hampered by the unreli- committed to cost sharing. The Panel emphasized ability and high cost of motorized pumping. Combining however the need for other organizations, particularly domestic water supply with micro-irrigation and livestock donors and specialized agencies, to increase their watering could have appreciable economic benefits for efforts along similar lines. village communities, especially, but not solely, in the dry Close collaboration will therefore be sought with zones. Studies are planned to assess the demand and governments and donor agencies to benefit from the cost-benefit of such multi-purpose use of handpumped combined experience gained so far, and to work towards water. the common goal - rapid implementation of sustainable 16 Table 2.1 Options for Community Water Supply Step Type of Service Watersource Quality protection Water use Energy source Operation and Costs General remarks LPCDa maintenance needs Groundwater Good, no treatment Well-trained operator; High capital and Most desirable Gravity reliable fuel and O&M costs, service level, but 5 House Connections Surface water May need treatment 100 to 150 Electric chemical supplies; except for high resource Diesel many spare parts; gravity schemes needs Spring Good, no treatment wastewater disposal Groundwater Good, no treatment Well trained operator; High capital and Very good access Gravity reliable fuel and O&M costs, to safe water; 4 Yardtaps Surface water May need treatment 50 to 100 Electric chemical supplies; except gravity fuel and institu- Diesel many spare parts schemes tional support Spring Good, no treatment critical Groundwater Good, no treatment Gravity Well trained operator; Moderate capital Good access to Electric reliable fuel and and O&M costs, safe water; cost 3 Standpipes Surface water May need treatment 10 to 40 Diesel chemical supplies; except gravity competitive with Wind many spare parts schemes; handpumps at Spring Good, no treatment Solar collection time high pumping lifts Low capital and Good access to 2 Handpumps Groundwater Good, no treatment 10 to 40 Manual Trained repairer; O&M costs; safe water; few spare parts collection time sustainable by villagers Improved traditional Groundwater Variable Very low capital Improvement if 1 sources Surface water Poor 10 to 40 Manual General upkeep and O&M costs: traditional source (partially Spring Variable collection time was badly protected) Rainwater Good, if protected contaminated Surface water Poor Traditional sources Groundwater Poor Low O&M costs Starting point for 0 (unprotected) Spring Variable 10 to 40 Manual General upkeep (buckets, etc); supply Rainwater Variable collection time improvements a. LPCD = liters per capita per day CLapter 2 Choice of Community Water Supply Technology The technology choices open to planners of community have failed to live up to expectations suggests that an water supply (CWS) programs are best characterized by important factor was the choice of a CWS technology the type of water points they provide: handpumps; which was not sustainable with the resources available standpipes (i.e. public taps); yardtaps; and others, to the community. The important message for CWS such as dug wells without pumps. Costs and potential planners is that: benefits differ for each option, and technology choice cannot realistically be made on the basis of cost alone. * The technology chosen should give the Measuring benefits is difficult, involving technical, community the highest service level that it is economic, behavioral, nutritional, and public health willing to pay for, will benefit from, and has factors among others. But an estimate of benefits has the institutional capacity to sustain. to be made in order to compare technologies and select the most appropriate. The scale of benefits is influenced In general, technologies offering higher service by two key technical factors - the service level (i.e. levels place correspondingly higher resource demands the distance water must be hauled from the water point on the benefiting community. The most obvious is the to the dwelling, queuing plus filling time for each water need for more capital investment, but equally important hauler, and the ease of drawing water); and the are operation and maintenance costs and the demands reliability with which water is available at the water for technical skills and materials (fuel, chemicals, etc.). point when needed. The low cost and simplicity of handpumps have Technology Options proved attractive to government agencies and external support organizations seeking maximum impact from Table 2.1 shows the different CWS technology options limited budgets, and have led to increasingly widespread as a series of steps. Provided satisfactory reliability implementation of handpump projects in recent years. can be achieved, the level of service rises with each But handpumps also have their limitations: though the step, as do the total costs, the complexity of the haul distance will normally be shorter than from the system, and the difficulty of designing, constructing and original traditional sources, water must still be pumped maintaining it. by hand and carried home, with corresponding costs in The step analogy of water supply improvements is time and effort; and maintenance needs, though simple useful, but it should not be taken too literally. When when compared with motorized pumping or water reliability is taken into account, the level of service supplies involving treatment facilities, may still be actually provided is often much lower than planned. beyond the capabilities of the community. Also, the steps are not equal; progress is not If motor pumps can be reliably operated and main- necessarily achieved one step at a time; and not tained, the community may be willing to pay more for the everyone will start at the bottom. Many communities may improved service level. As pumping lift increases, hand- find that one of the lower steps offers a satisfactory pumps produce less water and require more effort to option for the foreseeable future, while others will pump, increasing comparative advantages of well-run upgrade to a technology giving a higher service level motorized pumps with standpipes or yardtaps. The when the community acquires operational experience options need to be compared in a consistent economic and the capacity to manage a more complex system. and financial framework, which also takes account of The main task in planning CWS improvements is to physical and institutional resource constraints. select the technology which will give the highest service Close scrutiny of the reasons why past projects level practical with the available resources: 19 "Success or failure depends primarily on one factor: can the new water supply be sustained?" A - 11i; Groundwater is usually preferred over surface water _01 _ ql tfr as a source, because it avoids the need for special, often unreliable, measures to safeguard water quality or improve it through treatment. If simple rules are followed about the proximity of latrines and the construction and management of well surrounds, groundwater should be ^tW,, ._,M tU # safe from bacteriological contamination. _*N-M >>> SaS ]11When well water is not up to drinking standards, a combination of sources may be the right answer, as the example from Thailand in Box 2.1 shows. In many areas of Thailand, none of the water sources alone satisfies '7-- _ - : -i- - domestic needs. Dug wells, with or without covers and The skills and resources needed for operation and maintenance handpumps, tend to be both chemically and bacterio- are important considerations when selecting an appropriate logically polluted. Drilled wells have an unacceptably water supply technology. Handpumps suitable for servicing by high mineral content, while rainwater storage provides village caretakers stand a good chance of providing reliable only enough water for drinking and cooking. The program service. therefore uses a mix of sources for different purposes. Investment Efficiency * Financial resources (for capital and recurrent costs); When resource constraints are applied to the selection of an appropriate water supply technology, it may turn * Physical resources (water and energy); and out that improvement of traditional sources (Step 1 in Table 2.1) is the only feasible option. In this rare case, * Organizational resources (manpower and no further comparison with other options is needed. In institutional). most situations, however, comparison is needed of several feasible options, in which the benefits expected If that selection is right, the scheme can be from the different service levels vary, as do the costs. expected to provide the desired service level for many A common approach is for the goverpment, years, and may later be upgraded to, or replaced with, a sometimes in collaboration with donors, to set a target technology giving a higher service level. If, on the other for a desired service level, and to select the feasible hand, any of the resources needed for the chosen system which gives the lowest total cost (annualized technology are not reliably present, none of the capital cost plus recurrent cost) for that service level. anticipated benefits may materialize after construction. This method has often been applied, in an effort to bring Success or failure depends primarily on one factor: can small but important improvements to as many people as the new water system be sustained? possible. Its weakness is that it takes no account of the In terms of service level, the technology options in different levels of benefits provided by different levels of Table 2.1 can be divided into two groups, according to service, and does not leave room for those communities the way in which water is conveyed to the users' homes. which are willing and able to pay for a higher service level Steps 0 through 3 involve communal supplies from which to express their preference. In other cases it may lead to the water is carried by the user, while in steps 4 and 5 the selection of an inappropriately high service level for pipes transport it to individual homes. only a few people, leaving the majority of the population The level of service provided by communal supplies without coverage. varies according to the amount of time it takes to travel In the Philippines, for example, even in relatively to and from the source, to queue, and to fill containers; it high income areas with good infrastructure, a large depends too on the reliability of the supply at the source. subsidy provided for the construction of wells with Standpipes are more convenient than handpumps in that handpumps has meant a very low demand for piped water is drawn from a tap rather than by manual pumping, schemes (offered with virtually no subsidy). Another but, unless a gravity supply is available, they must rely example comes from Thailand, where a donor-assisted on motorized pumps and elevated storage to maintain project initially tried to put just a single well in each supplies. village. The strategy failed because the communities did 20 Box 2.1 Evaluating Technology Options: A Case Study from Thailand Of the four basic water resources available in rural potable water available to all households throughout Thailand - rainwater, shallow aquifers, deep the year. One of NESDB's projects is the Thai- aquifers, and surface water - none is able alone to Australia Village Water Supply Project, which began provide all the needs for community water supply. A in 1983 and has carried out studies to evaluate the typical Thai household needs about 5 liters per effectiveness and cost of different water supply person per day of safe, palatable water for drinking, options. cooking and cleaning teeth. Other domestic uses, Surveys showed that rainwater storage and such as washing, bathing and latrines, require about capped shallow wells are the only facilities which 50 liters per person per day. On a seasonal basis, consistently provide safe, palatable water, and that each rural family also needs about 4000 m3 per year treatment to improve the quality of water from other for supplementary irrigation. sources is not practical. Handpumps on drilled wells Rainwater, collected from roof runoff and are a major source of domestic water supply. In Khon stored in jars and tanks, is generally of good quality, Kaen Province, for example, 65% of the villages but barely enough to meet drinking needs. Shallow have a government tubewell, supplying 25% of aquifers, tapped usually by open wells, or domestic needs in the wet season and 40% in the dry occasionally by a sealed well with a suction season. However, only 10% of the wells are used for handpump, are commonly used for drinking and other drinking. domestic uses, though bacteriological quality from Cost analyses (Box Table 2.1A) show that open open wells is unacceptable for drinking, and in the shallow wells are by far the cheapest form of water-short Northeast the wells often dry out during domestic water supply. Rainwater storage in jars is the dry season. Deep aquifers, tapped by more economic than in tanks, costing about the handpumps on drilled wells provide water with same per household per year as a covered shallow acceptable bacteriological quality, but in most areas well equipped with a suction pump. Ponds and weirs the chemical quality is poor, and the taste is have high capital costs, while the highest cost per unacceptable. So, though the supply is reliable, it is household is for drilled wells with handpumps. rarely used for drinking or for agricultural needs. Quality and cost criteria together have led Surface water comes from natural lakes and NESDB to a strategy based on a mixture of rivers, and from man-made ponds, irrigation ditches, technologies. Despite their higher costs, deep wells weirs and reservoirs. The water is of poor quality and with handpumps are popular with villagers, because unsuitable for drinking, but can provide domestic and they provide convenient and reliable clean water agricultural supplies. suitable for most domestic purposes (but not Since 1966, Thailand's National Economic and drinking). Because of these benefits, Thai Social Development Board (NESDB) has been communities are willing to pay more for handpumped implementing a national project which seeks to make supplies. Box Table 2.1A Costs of Rural Water Supply Options in Thailand (US$) Capital Maintenance Totalannual Households Annual costl Type of system cost cost cost served household Rainwaterjar 19 0 2.50 0.31 8.15 Rainwatertank 245 1.85 29.00 1.78 16.00 Shallow dugwell without handpump 93 0 15.00 20 0.75 Shallow dugwell with handpump 540 93.00 165.00 20 8.15 Drilled deepwell with handpump 2660 93.00 440.00 20 22.00 Pond 1850 3.70 305.00 20 15.25 Weir 10000 18.50 1625.00 100 16.25 Note: Converted from Baht at US$1.00 = Baht 27.00 CHOICE OF COMMUNITY WATER SUPPLY TECHNOLOGY 21 It would be inappropriate however to promote handpump-based water supplies in areas with good infrastructure, where people are willing and able to pay for the greater convenience of yardtaps or household. wells, especially when a reliable electricity supply permits the use of electric pumps. If financial and institutional resources are available to support operation and maintenance, consideration of the higher level of service should be encouraged. Seemingly lower cost ~ S--; ~. options will fail under these conditions, even when subsidized by government agencies, because the low - !t " -_. .level of service that they provide does not meet the -- _ ~ users' aspirations and will not be accepted. '_inwater - ', "~ are Regardless of how the capital costs of CWS projects --are financed, recurrent costs (for operation and Rainwaterstorage can be an effective and economic option for maintenance) should be borne by the community. The providing drinking water, and should be analysed as a possible Project has provided further evidence to support the componentof CWSprograms. view that community involvement is a critical element in successful CWS maintenance, and that community not value the improvements highly enough to contribute management, including financial management, of to their maintenance. A second approach provided system operation and upkeep is the only way to achieve several standpipes dispersed around the villages, but acceptable reliability at an affordable cost. also failed for the same reasons. Only when yardtaps Besides analysing costs to the direct beneficiaries, were brought to most villagers did the scheme become it is also necessary to consider the capital and recurrent successful. Though the yardtap plan was much more costs which would result from the planned investment in costly, households were willing to pay because they the national perspective. For national planners to be able valued the extra convenience. to make choices on economic grounds, all quantifiable costs should be included and adjusted for taxes, Costs subsidies, price controls and exchange rate imbalances, using accepted project analysis techniques. All too Capital costs of various levels of service depend very often, the rural cost structure is distorted by agricultural much on local conditions, but the relative costs of the prices, and under these conditions there is little different groundwater-based technologies are apparent incentive or capacity to generate locally the necessary even though the range of costs may be quite wide. Wells funds for rural development without government equipped with handpumps generally cost from US$10 to assistance. US$30 per capita; for motorized pump schemes with Incomes in rural areas of many developing countries standpipes, the range is US$30 to US$60 per capita; and are typically between US$50 and US$300 per person per for yardtap services the per capita cost can be expected year, with the distribution of cash and kind income to range from US$60 to US$1 10 per capita. With some varying widely. Even so, the annualized capital and 1,800 million rural people in need of improved water recurrent cost of low-cost water supplies should supplies by the end of the century, the extra costs of constitute only a small proportion of that income. high-level service can be justified only when benefi- Table 2.2 includes low and high cost estimates for ciaries are willing and able to pay the extra costs in full. the different technical options, to illustrate the financial The Project has focused on CWS systems involving resources which need to be mobilized for different types wells with handpumps because the large needs and of water supply improvements. To take account of the limited resources of many developing countries mean range of cost data that was obtained under similar that such lower cost technologies will be the only conditions from a large number of projects in Africa and practical first step if as many people as possible are to Asia, a "low" and a "high" case are given. "Low" be served in a reasonable time period. represents a situation of favorable hydrogeology and efficient implementation and maintenance (with community participation); "high" is based on a combination of adverse conditions which exist on some "... high-level service can projects. Estimation of capital and recurrent costs ahead of be justified only when project implementation is difficult, especially at the beneficiaries are willing beginning of a CWS program. Judgments may sometimes have to be made on the applicability of data and able to pay the extra from comparable programs in other countries, and . ,, estimates must then be refined as the program evolves, costs in full. as in the example from Thailand described in Box 2.1. .___________________________________________ However, most countries have some experience of 22 Table 2.2 Community Water Supply Technology Costs (For a community of 400 people) Low Hiah Technology Handpumps Standpipes Yardtaps Handpumps Standpipes Yardtaps CapalQQ cost $) Wells1 4,000 2,000 2,500 10,000 5,000 6000 Pumps (hand/motor) 1,300 4,000 4,500 2,500 8,000 9000 Distribution2 none 4,500 16,000 none 10,000 30000 Sub-total 5,300 10,500 23,000 12,500 23,000 45000 Costpercapita 13.3 26.3 57.5 31.2 57.5 112.5 Annual cost (US$/yeart Annualized capital3 700 1,500 3,200 1,400 3,000 6000 Maintenance 200 600 1,000 400 1,200 2000 Operation (fuel) none 150 450 none 300 900 Sub-total (cash) 900 2,250 4,650 1,800 4,700 8900 Haul costs (labor)4 1,400 1,100 none 3,000 2,200 none Total (including labor) 2,300 3,350 4,650 4,800 6,900 8900 Total annualized costper capita Cash only 2.3 5.6 11.6 4.5 11.8 22.3 Cash + labor 5.8 8.4 11.6 12.0 17.3 22.3 Notes: 1. Pumping water level assumed to be 20 meters. Two wells assumed for handpump system (200 persons per handpump). 2. Distribution system includes storage, piping, and taps with soakaway pits. 3. Capital costs with replacement of mechanical equiment after 10 years annualized at a discount rate of 10% over f 20 years. 4. Labor costs for walking to the water point, queuing, filling the container, and carrying the water back to the house. Time valued at US$ 0.1 25/hour. several levels of CWS technology, and careful review of as the new water supply functions reliably. total system costs can provide a basis for estimates on Health benefits, in terms of reduced medical future projects. However good the present data base care, improved productivity, etc., have often proved may be, monitoring and evaluation of new projects is a difficult to isolate and quantify for any single intervention valuable way of improving forecasting for future like community water supply. Health impact studies have schemes. rarely been designed adequately to isolate health improvements due to provision of safe water from those Benefits brought about by other influences (nutrition, sanitation, health education, etc.). Some benefits from CWS. improvements are immediate A recent review of a large number of impact studies and highly visible. Access to a convenient source of does show that significant health benefits can be clean water brings time savings and reduced obtained from well-designed CWS programs (Box 2.2). drudgery for the household water carriers - commonly What emerges is that community water supply is women and children, while the easy availability of water perhaps not a sufficient intervention in itself to improve for washing and bathing encourages greater cleanliness health and quality of life, but it is an essential part of any and leads to better living conditions. Other intervention package. benefits, of which the most important is better health, Protecting the source from contamination can may be less immediately apparent, and will often depend reduce transmission of some diseases, but when water on additional inputs such as sanitation improvements is carried from the water point to the home and stored and hygiene education if maximum impact is to be there, recontamination occurs, as a number of studies obtained from the CWS improvements. have shown. This recontamination negates the need to Assessment of benefits is a critical element in CWS insist on a high water quality standard at the source, as technology selection, as widespread implementation of is the policy in the industrialized countries. Emphasis improvements at the pace needed to meet global needs should instead be placed on improvements in hygiene can only be achieved if communities are able to make a through sanitation, health education and other major contribution towards the costs. Contributions in interventions, so as to reduce disease transmission cash or kind depend on the community valuing the through water in the home. benefits to be obtained, and will continue only for as long A more direct benefit of improved water supply CHOICE OF COMMUNITY WATER SUPPLY TECHNOLOGY 23 Box 2.2 Health Benefits from Water Supply Evaluation of health benefits resulting from an improved water supply is a subject of some controversy. A number of well-designed studies have Box Table 2.2A Reduction in Diarrheal produced substantial evidence that health benefits Morbidity Rates due to Improvements arise when communities receive improved water in Water Supply and Sanitation supplies, but the picture has been confused because other studies have given inconclusive results, largely Improvementin % reduction because they were not properly designed to isolate compounding factors. Waterquality 16 There is little room for doubt that water plays a key Wateravailability 25 role in the realization of health improvements from Both quality and availability 37 combined interventions, including promotion of such Excreta disposal 22 measures as personal hygiene. Much more difficult to establish is the priority that improved water supply Source: SA Esrey, RG Feachem and JM Hughes should be given in an investment program over other Interventions for the control of diarrhoeal diseases health interventions, such as oral rehydration, among young children: Improving water supplies and immunization and sanitation. Recent advances in excreta disposal facilities." WHO Bulletin 63(4), 1985 methodology, particularly the introduction of the case pp637-640. control method, will allow impact studies to be carried I out retrospectively, at lower cost. The target group for health interventions is usually magnitude of the effect varied considerably with the young children, as they are most susceptible to a presence of other risk factors, such as poor feeding variety of diseases, especially those causing practices and low literacy rates (Esrey, Feachem and diarrhea. It is estimated that nearly 5 million deaths a Hughes, 1985, pp 764-768). year occur in children under five years of age (the Separate research on the effect of hygiene statistics do not include China), and that each child education shows that it may further increase the under five averages 2.5 incidences of diarrhea a year impact. The general conclusion to be drawn from the (Snyder & Merson 1982). evidence is that: A recent review of impact studies from many countries shows a substantial reduction in diarrheal Well-designed projects combining the avail- morbidity rates (frequency of diarrhea) in young ability and quality of water supply, excreta children attributable to water supply and sanitation disposal, and hygiene education may improvements. Improvements in water availability or achieve a reduction in diarrheal morbidity excreta disposal were shown to have more impact on of 35-50% - and more for diarrheal mortality diarrheal morbidity than improvements in water quality, unless oral rehydration has been success- while a substantial impact (37% reduction) resulted if fully introduced (p768). both quality and quantity were improved. The studies also showed a reduction in diarrhea mortality as a As part of the Project, the International Centre for result of improved water supply and sanitation, but the Diarrhoeal Disease Research, Bangladesh (ICDDR,B) systems is the reduction in the time and energy improved supplies and suggesting the optimum level of required to collect water. Once water is available in a service for given economic conditions. village, the chore of collecting it will take less than an Estimating the value of the time saved can be hour a day, compared with many hours in the frequent difficult since, in economic theory, it will depend not only cases where traditional sources are long distances on alternative income-producing activities but also on away. such things as caring for children or the value of leisure. It is possible, using the method of analysis Some have suggested using potential income from described in Annex 3, to compare the costs and handicrafts, street peddling, garden plots, etc., as a benefits of the various CWS options, assessing benefits notional value of time; others stress that willingness to on the basis of time savings alone. pay, measured by properly designed household surveys Because people readily perceive the relationship (or in some cases indicated by prices paid to water between improved water supplies and time savings, both haulers) is the only way to obtain good estimates. the Inter-American Bank and the World Bank have Irrespective of the precise value attributed to time, placed increasing emphasis on the time saved in comparison of the estimated benefits from time savings carrying water as one way of assessing the benefits of with the calculated costs of proposed CWS schemes 24 is conducting an impact study on the effects on contact and contaminated food. The manner in which diarrheal morbidity in young children of combined different risk factors interact to cause a particular improvements in water supply (drilled wells with disease incidence is not fully understood, but it is handpumps), health education, and latrine construc- clear that, to realize the full health benefits from RWS tion. Preliminary results from a study area in Mirzapur, improvements, sanitation and food hygiene must also where handpumps and health education have been be improved. provided, show a reduction in diarrhea cases in It has at times been argued that oral rehydration children under 5 of 31% over a period of one year, should be given priority over water supply when compared with a control area in the same district. improvements for cost reasons. While oral Implementation and monitoring will continue, to rein- rehydration, applied through a primary health care force the health messages and improve utilization of program, is a very effective and relatively inexpensive the installed facilities, and to collect more impact data. means of reducing diarrheal mortality, other For some diseases, water provides the only interventions are needed to reduce morbidity and to transmission route, so that improved supplies are the prevent or treat chronic or dysenteric diarrhea. This only way to reduce disease incidence. The best known integrated approach to health care forms the four-part is Guinea Worm (Dranunculiasis), a debilitating strategy of the Diarrheal Disease Control Program of disease, occurring in India and West Africa, and the World Health Organization: transmitted by drinking water containing an organism which is a host for the Guinea Worm larvae. Provision 1. Improved case management, with particular of a safe potable water supply is a highly effective emphasis on the early use of oral rehydration preventive measure, as documented in two towns in therapy in acute diarrhea and on appropriate western Nigeria. Before the supply of piped water in feeding during illness and convalescence; 1963 and 1965, Fiditi and Igbo-Ora (combined population 30,000) recorded incidences of Guinea 2. Improved maternal and child health care, with Worm of 20% among schoolchildren in one town and particular emphasis on breast-feeding, weaning 60% among the total population in the other. No further practices, personal and domestic hygiene, and cases were reported two years after completion of the maternal nutrition; water supplies, even though the disease was endemic in the surrounding areas (Source: R Muller: 3. Improved use and maintenance of drinking water "Dracunculus and dracunculiasis". In: B Dawes, ed. and sanitation facilities, and improved food "Advances in parasitology, Vol 9", New York: hygiene; and Academic Press, 1971, pp 73-151). Water supply improvements have to be seen as 4. Detection and control of epidemics. only one of several interrelated health interventions, forming an integrated program of health care for a Source: RG Feachem, RC Hogan, and MH Merson: particular community. Unlike Guinea Worm, most "Diarrhoeal disease control: reviews of potential diseases have multiple routes of fecal-oral interventions". Bulletin of the World Health transmission, including water, person-to-person Organization, 61(4),1983, pp 637-640. can provide a useful indication of the level of service to the chosen technology: financial, physical and organi- be provided and the technology to be selected. Thus, for zational. example, although one well per 500 persons would provide a lower cost per capita than one well per 200 Financial Resources persons, the additional time spent queuing would be so great that villagers would simply prefer to continue If CWS projects are to be implemented at the pace collecting water from an existing unimproved source. necessary and on a wide enough scale to match the Some of the main conclusions from applying cost- needs of developing countries, capital and recurrent benefit analysis to the choice of CWS technologies are costs must be considered within a framework of limited discussed in Annex 3. resources. Only if a sizeable proportion of total costs are recovered from the benefiting communities, will it be Resource Constraints possible to generate funds and replicate projects on the scale needed. Choice from the technology options is not only based on This does not mean that governments or donor a comparison of their benefits and costs, but also on the agencies should stop supporting investments in feasibility of providing the resources required to sustain community water supply, but only through mobilization of CHOICE OF COMMUNITY WATER SUPPLY TECHNOLOGY 25 infrastructure needed to keep it functioning reliably. Converting the high priority for water supply improvements felt by communities into contributions towards their costs is a challenge to governments, which can be met only by good communily education and WI. ' _.; > participation. The principle of community involvement or *1 f 2 ~~~~~~~~~~~~participation in CWS development has been promoted for -- --.- 5 ' ----- t many years and most agencies have accepted that g / - -$ s . ~ z \~ some form of participation is a prerequisite for success. There is evidence from all over the world that it is the I ,= . j S > schemes developed by the community (with technical 4 . e r ! } i -_ assistance from outside) which stand the greatest chance of being sustained in good working order. Jr.. t 4sA Constraints on available funds for capital and recurrent costs mean that low-cost options will be favored in an environment where maximum coverage is X ;_ 76 | ¢ F _ ~~~~~~~~~~~the goal. .s.. low cost options will be favored in an environment where maximum coverage is the goal." Physical Resources Level Oeratio and Mantenane VLOMWater resource limitations are the first and perhaps Village Level Operation and Maintenance - VLOM - easiest to assess of the physical resource constraints handpumps has a substantial effect on reducing recurrent tosbe taken o acc ounwh comparin nts costs. The alternative of centralized maintenance is the only to be taken into account when comparing CWS option formotorized pumps. technology options. Surface water sources (rivers, springs, etc.) need to be identified, and compared with groundwater in terms of availability and water quality. local cash resources is there hope for widespread rapid Compared with surface water, groundwater as a and self-sustaining improvements in the global situation. source has a number of advantages: An important difference between handpump schemes and motorized-pump systems is the degree * It yields safe water which rarely needs treatment. that the latter depend on support from outside the community (it will become clear in Chapter 3 that many * It provides a substantial storage buffer to cope with present handpump projects also rely on external seasonal variations in supply and demand and with support, but the Project has shown that the VLOM prolonged droughts. (Village Level Operation and Maintenance) approach can minimize or even eliminate this dependence, resulting in * It enables a variety of relatively simple installations much higher reliability). Once that outside support is to supply water directly to the user at low cost, by fully reflected in cost estimates, sizeable differences manual, electric, diesel, wind, or solar powered emerge in annual recurrent costs per capita of the CWS pumps. options. Because of the urgent need, re-emphasized by the * It allows for phased development without the high Water Decade, to provide all rural populations with at "up-front" costs for storage, transmission lines, least a minimum level of improved supply, it will be treatment plants, etc., needed to meet final demand necessary for most of the construction costs of piped in a surface water scheme. systems, storage reservoirs, etc., associated with the higher levels of service in Table 2.1 to be recovered from Of most importance in CWS planning is the safety the community. In evaluating an individual project or that groundwater usually offers. Because surface program, planners need to be sure that finance (sources waters are prone to serious contamination, even of expenditure and repayments) is available for the temporary failure of the treatment system can result in service level under consideration - including the an outbreak of waterborne disease. Reliable operators, spare parts and uninterrupted supplies of fuel and 26 chemicals are therefore a prerequisite of systems based Figure 2.1 Pumping Lift Frequency on surface water sources. Distribution in Field Trials In choosing a water source, it is far preferable to find one which supplies sufficient good quality water and to 30 protect it, rather than to take water from a doubtful Median 12 meters source and treat it. Springs, protected upland streams 25- and groundwater are thus the preferred choices. There O are however some situations in which groundwater may Z 20- prove unsuitable. Naturally occurring salts can make the w water unpalatable or aesthetically unacceptable (e.g. 15 high iron levels impart a bitter taste and can stain food and laundry), and in some cases may be damaging to 10 health. The level of groundwater and the potential yield of 5 drilled wells have to be assessed. Handpumps usually turn out to be more economic the smaller the pumping lift ° and the lower the cost of well construction. As figure 2.1 10 15 20 25 30 35 40 45 50 shows, the vast majority of rural water supply wells Pumping lift (meters) worldwide have pumping lifts of less than 25 meters, for which handpumps can provide very good service. In the Project field trials, efforts were made to site wells where However, as the pumping lift increases, the effort groundwater was as deep as possible - the aim being to develop handpumps suitable for deepwell applications. needed to pump water manually also rises. Below 40-50 However, as the diagram shows, 75% of the wells involved meters, motorized pumps should be used wherever they pumping lifts of less than 20 meters, and 85% were less than 25 can be maintained. The quantities of water pumped from - meters. It seems likely that these figures are a good reflection wells for domestic water supply are small, and will rarely oftheglobalsituationintermsofgroundwaterdepth. exceed the natural recharge capacity of an aquifer. There are however numerous examples of lowered water price several-fold, but the actual cost of the fuel is less tables caused by prolonged pumping for irrigation significant than its reliability. All too often, diesel fuel is (Bangladesh, India and China among others), and this diverted to other buyers rather than the isolated pump, can have a damaging effect on nearby CWS wells. or access is prevented by bad road conditions, or the Hydrogeological knowledge is important in delivery truck breaks down. determining well yields. In the basement rocks of Africa Successes and failures of major pumping projects and India for instance, it can be difficult to site wells based on renewable energy resources (wind or solar) are even to draw the minimum acceptable flow for a not so well documented. Renewable energy has one handpump (about 0.2 liters/sec), and very large clear advantage over diesel, in that there is no depen- drawdown can be expected if motorized pumps are used. dence on external fuel supplies. However, wind and solar To take advantage of the economies of scale that pumping schemes have substantially higher initial costs are possible with motorized pumps, wells are typically and they do share diesel's other big handicap - the need designed to provide sufficient yield to meet the total for more sophisticated and costlier maintenance skills demand of a small community. Water use in a community and spare parts that are not readily available to the of 400 people will be from 8 to 50 cubic meters a day, community. Some components of solar systems that depending whether standpipes or yardtaps are installed, have been introduced in developing countries cannot and that will usually mean a pump discharge rate of 1 even be repaired at the country level, but have to be liter/sec or more. Achieving such well yields in basement replaced with new equipment or shipped to the overseas rocks can make wells very expensive, and success manufacturer if a breakdown occurs - a logistically rates are likely to be low. prohibitive option. Renewable energy systems also involve extra costs in comparison with handpumps, Energy Resources include primarily human, electric, because of the back-up water supply needed to cope diesel, wind, and solar. Any CWS system which depends with times when the energy source is not available. on something other than human energy for its operation These constraints do not rule out motorized pumps, involves an added risk of failure through supply but they do mean that ways of ensuring reliable supplies interruption (electricity from the grid, diesel, wind, etc.). must be worked out and costed, before the community These reliability risks can be minimized by proper takes the decision on the affordability of higher service design, but often this means much higher costs and levels. forces the community to rely on external resources outside its control. Organizational Resources In most cases, water can be pumped for substantially less cost if an electric grid is available than These are perhaps the most difficult to evaluate in if the pump must be driven by diesel, wind or solar power. planning a CWS program, which may explain why so Trucking diesel fuel over long distances can raise its many projects founder because the right skills, materials CHOICE OF COMMUNITY WATER SUPPLY TECHNOLOGY 27 or institutional structures are not available to keep them water supply sector, particularly in rural areas. Lack of functioning. The better trained the mechanics, the more professional and semi-professional staff is one of the frequent the outlets for spare parts, the closer and more top constraints reported to the World Health reliable the fuel supply, the better the supervision of well Organization in that agency's monitoring of progress in construction, etc., the greater will be the reliability of the the International Drinking Water Supply and Sanitation CWS system. Decade. Evidence is easy to find: many of the disused Organization and management of available skills schemes in urban and rural areas are idle because the and equipment becomes more complex as the service personnel could not be found or retained to organize and level increases - a powerful argument for step-by-step carry out the repairs needed. progress. For handpump schemes, the organizational Assessment of organizational resources has to be structure needed involves creation of a mechanism such carried out at both national and community level, and a as a water committee to manage collection of charges decision reached on the duties for which each will take from users, to initiate repair and maintenance activities, responsibility. Reliance on national organizations for to pay for maintenance services, and to procure spare regular maintenance support is not a satisfactory option, parts. Motorized pumping schemes include these as it becomes an increasing logistical burden on central elements and, in addition, require an operator, a reliable government as more and more systems are installed, electric power or diesel fuel supply, a greater variety of and it is susceptible to future policy changes. Self spare parts and tools, and more advanced mechanical reliance at the community level is the only workable repair skills. alternative in the long run, and the community must If reliable electric power is available from a central assess whether it can provide the level of skills and grid, an electric pump can be a relatively inexpensive equipment needed for a higher level of service, or opt for and operationally simple means of lifting water. However, the lesser maintenance needs of a handpump-based if the power is irregular, or available for only short system. periods each day, daily water demand may not be met and expensive elevated storage may have to be The Right Choice increased. When the supply is intermittent, users tend to leave taps open, to fill containers when power is Returning to the steps in CWS improvement presented in restored. Distribution is then inequitable, with only those Table 2.1: closest to the storage tank being able to obtain water, and there is high wastage. Automatically closing taps Step 1 - Improvement of traditional sources - offers and flow restrictors have sometimes been successful in few benefits, either in terms of time savings or improved saving water on larger, mainly urban, schemes, but they water quality. It may nevertheless be the only choice are expensive and unpopular with users, who quickly available for communities which have not even the find ways to disable them. financial or organizational resources to manage the Diesel pumping is generally less reliable than upkeep of a handpump. electric pumping. In rural areas, it is difficult to ensure reliable fuel supplies; and diesel engines have more Step 2 - Handpumps - has clear advantages over complex maintenance requirements. An example from Step 1, particularly in its use of groundwater without Nigeria illustrates the resource needs. A typical costly or unreliable water quality protection or treatment installation consists of a 40m deep drilled well with a usually associated with improvement of surface water pumping lift of about 20 meters, a submersible electric sources. Where groundwater is not available in adequate pump, a diesel generator housed in a small building, and quantity or quality for handpumps, other feasible options a storage tank with one day's capacity. Watchmen are will need to be explored. Typically, handpump-based employed round the clock for security and to prevent schemes have often had a high proportion of pumps out wastage, and one or two operators run the generator and of order at any one time, because one or more of the carry out basic maintenance. Scheduled maintenance important components necessary for success has been and major repairs are the responsibility of mechanics lacking. Specifically, projects have suffered from: wrong from the government workshop. The users are choice of handpump (low durability, unsuitable for local responsible for ensuring that there is enough diesel. One maintenance, poor installation, lack of spare parts, organizational structure involves the watchmen noting etc.); insufficient community involvement and comm- frequent users and establishing a roster of families to unity financing; poor borehole design and completion supply the fuel for the generator (covering transport (sand inflitration, poor water quality, insufficient yield, costs as well). The system is dependent on all the inputs etc.); central rather than community-managed main- being reliable and is somewhat fragile, as once the one tenance (high cost, long delays). More recent schemes day storage is used up, users must revert to traditional show a marked improvement in performance, but further sources. improvements in the implementation of systems are still Availability of skilled manpower is a critical needed. The critical elements now known to be consideration in technology choice, as it has a direct necessary for sustainable and widely replicable impact on the feasibility and cost of installing and programs, are discussed in detail in Chapter 3. sustaining any type of system. Developing countries typically have a severe shortage of trained people in the Steps 3 and 4 - Standpipes and Yardtaps - The step 28 logistical and technical support being available as it does on the selection of hardware. It means too that increasing dependence on mechanical or electrical equipment or on external supplies of spare parts, fuel or chemicals can prevent the planned service level from _Z~ being achieved, unless pre-planning can guarantee that necessary skills and supplies will be reliably available. Sustainability based on community resources is a vital PI , ; r -_ design parameter, if rural water supply is to expand r __W { _ ~--> _ without being a continual drain on scarce financial and 71' -, j \> > 4human resources, and will determine the speed with which CWS programs can be implemented on a wide _ ~~~~~~~~~~~~~~~scale. Assessment of CWS successes and failures Goursources need to be analysed throughout the developing world leads to the conclusion andcompared intermsofquantityandsquality. that experience in operation of a handpump system, and realization of the benefits of improved water supplies, can greatly enhance the chances of success with higher from manual to motorized pumping is a big one, markedly service levels implemented later. In exceptional cases, increasing the complexity of the system. Put simply, the even the resource commitments needed for a reliable increased complexity of CWS systems designed to handpump system may be too great to allow immediate provide progressively higher service levels brings added implementation, in which case simple improvement of risk of failure. As a result, the level of service actually traditional sources will be an essential first step. provided by motorized pump schemes is often much In selecting that first step, CWS planners must work lower than planned, though costs remain high. closely with the communities to be served, to evaluate Typical problems that arise in some projects with the resource demands of each technology option, and piped distribution systems include: compare them with available resources. The cost-benefit analysis alone may suggest that a higher service level * Intermittent supply (often made worse because than handpumps is appropriate, but in many parts of the users leave buckets under open taps, resulting in world, the organizational resources do not exist to uneven distribution and wasting a high proportion of sustain such a service level. Handpumps may then be the waterwhen the supply is restored); seen as a first-stage development, enabling experience to be gained at a comparatively simple level of * Power supply failure (electric grid supplies can be technology, while providing the opportunity for upgrading unpredictable, while diesel trucked over long the system later. If water resources allow, it may be both distances may be diverted for other purposes or practical and economic for diesel or electric pumps to be unreliable due to transport problems); fitted to wells originally drilled for handpumps, once the community has gained experience in managing the * Prolonged system failure because complex devices handpump project and has demonstrated a desire, a cannot be repaired locally (parts, tools or skills willingness to pay and the means to pay for the higher needed from outside); service level. The premise for technology selection (Page 19) was * Insufficient water available at the source for motor that: "the technology chosen should give the community pumping (often a seasonal problem with springs, the highest service level that it is willing to pay for, will streams or boreholes); and benefit from, and has the institutional capacity to sustain." The conditions may seem obvious, but all too * Drainage problems arising from the higher per capita often the caveats of sustainability, reliability and consumption and increased wastage. affordability are ignored in the desire of planners and donors to reach higher steps on the technology ladder. The overriding message for CWS planners is that, The result is allocation of limited resources to far fewer for any system, reliability depends as much on the communities than could be reached with sustainable necessary combination of management skills and services at a more moderate level. CHOICE OF COMMUNITY WATER SUPPLY TECHNOLOGY 29 Chapter 3 Projei" Plannin lmplementat o Wells equipped with handpumps are among the simplest correct poor pump performance) over all the field trials of community water supply technologies. Compared with is six months, with a wide range of values for the electric or diesel pumps, handpumps require substan- different pump models, depending on the water level, the tially less financial and institutional resources. With the number of people served, the type of pump, etc. Sturdy right planning, handpump-based community water construction and durable materials may increase the supplies can be adequately managed by benefitting interval between essential repairs - usually with added communities. But, regardless of whether a handpump cost and difficulty when the repair actually is needed. project is initiated as a first-stage water supply develop- But any handpump will need attention eventually. ment or as the long-term solution to a community's water Too many projects fail because the maintenance needs, experience shows that its success depends on needs cannot be met. It follows that a key objective of proper attention to six key elements of the whole system any community water strategy should be to create - the community, the aquifer, the well, the maintenance projects which can be kept in proper working order with system, the pump, and the finance. the resources known to be available. The fact that this Few failures can be blamed solely on the choice of apparently simple goal has proved so difficult to achieve handpump. Analysis of a great many schemes which in the past has called for a detailed analysis of the have failed to live up to expectations reveals one individual elements involved in water project planning predominant cause - inadequate arrangements for and operation. The result is a series of guidelines for routine operation and maintenance. Along with the improving the chances of providing reliable and sustain- choice of inappropriate pump technology, other prom- able community water supplies based on handpumps. inent causes of failure are: badly constructed wells; lack The guidelines cover the six interdependent parts of any of community involvement in project selection and handpump project - the community, the aquifer, the implementation; designing for the wrong service level; well, the maintenance system, the pump, and the siting pumps in the wrong place or at the wrong depth; finance. These key elements are discussed in detail in failure to ensure an adequate spare parts supply; the remainder of this Chapter, beginning with the issue disregard of water quality implications (taste or which has been shown to be central to overall success: corrosion); and failure to ensure funds for equipment or spares. The Maintenance System It is not sufficient to ensure that most of these prob- lems are avoided. Failure to deal with any one of the key Maintenance is an inevitable requirement of any system elements can jeopardize the success of the whole which depends on mechanical equipment, however scheme. Long-term success in fact depends on a simple that equipment may be. Historically, handpump complete package of hardware and software elements maintenance has been managed in many different ways, designed to ensure that the completed scheme can be though, with few exceptions, the principle has been to reliably sustained by the benefifting community. repair the pump once it has broken down rather than to Whatever manufacturers' literature may claim, the carry out scheduled preventive maintenance. maintenance-free handpump does not exist. The Project In most projects, a centralized mobile maintenance has tested most of the internationally recognized hand- team run by national or regional government or a donor pumps which were on the market when the field trials got organization is responsible for maintenance of large under way in 1982, more than 70 pump models in all. To numbers of widely dispersed handpumps. The central date, the average period between essential inter- organizations, with few spares for the pumps and ventions (actions necessary to repair breakdowns or vehicles, few operational vehicles, and long response HANDPUMP PROJECT PLANNING AND IMPLEMENTATION 31 : I S . i 9 a ^., j organization finances and organizes all handpump main- tenance and repair. Success is related to a sense of community ownership of the well and pump and can only x- L 4 - i * wa_ : be achieved when the organizational capacity of the * : _- i ^. i l community is adequate. C Aji_ t, ,, * i For community management to be feasible, the selected pumps must be suitable for simple routine main- |:' j E t_4x- _ t f tenance with basic tools and minimal skills. Common spare parts must be readily available in or near the comm- . , _ 6 = ~~~~~unity, which will usually mean that they are manufac- tured locally; and there must be a suitable community XY WrrD 1f j rWstructure for recovering the costs of maintenance and t-r - < . repair operations. The public sector has a crucial role to play in estab- lishing theframework for community maintenance by: [- .A..... - s i_ _ ., a * Ensuring the availability of handpump spares, by encouraging standardization, facilitating manufac- Women' are increasingly becoming involved in handpump main- ture through appropriate incentives, and enforcing tenance, with beneficial effects on the reliability of completed quality control; schemes. Here, Bangladeshi women caretakers are replacing a plunger seal. Caretakers need to be trained in basic technical skills, and must have ready access to regularly needed spare * Providing extension support for handpump main- parts. tenance through initial training of community leaders in financial management and pump caretakers in times, are often unable to provide this service satisfac- basic technical skills, and, periodic monitoring and torily. Their budgets are too low, management is inad- refresher courses to maintain standards. equate, and there are few incentives for staff to perform well. In the few cases where centralized maintenance is After an initial period of heavy involvement in highly effective, usually with donor support, it is construction and the initiation of community main- expensive. tenance, the role of the public authority will greatly In recent years, backed by strong promotion from diminish. A backup service may be needed for extra- the Project, developing country governments have ordinary repair (e.g. in case of clogging of the drilled recognized the shortcomings of centralized mainte- well), or intervention in the event that community man- nance and the need for greater community involvement. agement collapses. Periodic monitoring and refresher The concept of village-level operation and maintenance courses for caretakers and mechanics will also help to (VLOM - see Box 1.3 in Chapter 1) spread quickly assure reliable operation, and should form part of long- among handpump specialists and was adopted as a goal term extension support to community development. In by a number of manufacturers (though not always with addition, the government has a responsibility for the same interpretation as the Project intended). VLOM ensuring that quality standards are established, and to designs were consciously developed from 1981 monitor compliance with such standards through onwards, and a number have featured in the Project field periodic visits and testing procedures. trials and received technical and financial support for Under community management, maintenance and further development. repair is in practice carried out either by one or more Possible handpump maintenance systems cover a caretakers, or by an area mechanic servicing wide spectrum, from total community management with several pumps in the vicinity. no external intervention to complete control by the government water agency or other external organization 1A. Village Caretaker with no involvement of the community at all. In discus- Preventive maintenance and pump repair is carried out sing the merits of individual handpumps and their by one or more designated community members after a maintenance needs in the remainder of this report, it is minimum of training. Procurement and storage of useful to define two categories of maintenance, accor- essential spare parts and provision of necessary tools ding to whether the decision making rests with the water and equipment for pump maintenance is a community authority or the community, recognizing that each cate- responsibility and any external help is initiated and paid gory can only be an approximation to the actual situation for by the community. on any particular project or program. Costs are very low; transport is not required, except possibly to buy spare parts from the nearest outlet; 1. Community Management of breakdowns are infrequent because of preventive Maintenance maintenance, and response times when breakdowns do occur are usually short; and full control of the water The key element in this type of management is comm- supply is in the hands of the community. The community unity choice. The water committee or other community collects money to create a maintenance fund, which is 32 Box 3.1 Village-level Maintenance in Burkina Faso Village-level management of handpump-based comm- point committees with seven members, including two unity water supplies is a key feature of a rural water women and two pump caretakers, and the members supply project covering two provinces in Burkina were given training appropriate to their respon- Faso (Yatenga in the north and Comoe in the south- sibilities. west). Cost estimates from Yatenga indicate main- At the provincial level, enough area mechanics tenance costs of about US$0.05 per capita per year, were trained to service the pumps on the basis of one and monitoring by the Handpumps Project for two mechanic to every ten pumps. The mechanics them- years showed that 85% of the pumps were working at selves were nominated by the villagers, and were any given time. generally already involved in some type of mechanical The maintenance cost of the handpumps work (bicycle/motorcycle repair, etc). The project also compares with an estimate of US$0.65 per capita per helped to set up a distribution network for pump spare year for the cost of fetching water by traditional parts. means (bucket and rope) from Yatenga's typical well Responsibility for project execution was given to depth of 20 meters. national staff, and local well drillers were contracted Financed by the European Development Fund to rehabilitate and deepen old dug wells using hand- (EDF), the rural water supply project in Burkina Faso operated cable-tool rigs. has been modelled on principles developed by Pump selection too was made with village-level experts from African, Caribbean and Pacific maintenance in mind, and after competitive tender the countries and the European Economic Community at foot-operated Vergnet pump was selected and 465 a consultative meeting in Bamako, Mali, in 1979. A pumps were installed in the first phase. The Vergnet is major objective of the meeting's recommendations relatively light; the pump cylinder can be pulled from was that responsibility for operation and maintenance the well without lifting equipment; and wearing parts of water points should be transferred to the users. In can easily be replaced by trained area mechanics. the case of the EDF project in Burkina Faso, the aim Under the management of the water committees, has been to set up a system which is entirely routine maintenance is carried out by the pump independent of outside support (from government or caretakers, and the area mechanics perform major donor). repairs. Spare parts prices are controlled, while the Motivation of villagers to participate in main- area mechanics negotiate fees for their services with tenance of the completed project began early. The the water committees. The caretakers are generally communities were directly involved in the decision unpaid, though in some instances they may receive making processes - choosing between dug wells cashorlaborassistanceincultivatingtheirfields. without handpumps and drilled or dug wells with The water point committees collect money for handpumps, and taking part in selection of well sites. handpump maintenance and typically have a reserve Contributions were collected towards financing of the of about US$100 held in a cash box. The system is well superstructures, and villagers met the cost of working well, and costs are affordable by the comm- handpump installation and maintenance. unity. The handpumps are accepted and valued, and Before any well construction started, the vill- all the people directly involved (caretakers, area agers were told about the technical aspects of mechanics, local spare parts traders) are ready and potential water supply improvements, the advan- able to take on the necessary responsibilities. tages and disadvantages of water points equipped Paradoxically, the most fragile point of the main- with handpumps, and the commitments they would be tenance system on the EDF project is not the village- expected to fulfil in terms of financial contributions managed repair operations, but the supply, and maintenance duties. distribution and cost of the imported spare parts. The project helped in the organization of water used to buy necessary spare parts readily available on A comparatively recent development has been the the market, and to pay the caretaker(s) if necessary. substantial involvement of women in handpump Caretakers may sometimes be volunteers, but an maintenance. Concerns that training women in arrangement whereby they receive payment is strongly maintenance skills would be inappropriate to their role in recommended, as it helps to provide lasting motivation rural society have proved unfounded in a number of to stay on the job. This type of maintenance was the countries. On the contrary, women caretakers have original VLOM concept and it remains a long-term goal, demonstrated interest, enthusiasm and ability to keep offering the most effective way of maintaining new the water system working, because of their traditional systems. role as providers of water for the family. HANDPUMP PROJECT PLANNING AND IMPLEMENTATION 33 Box 3.2 Handpump Maintenance: The Three-tier System in India In support of India's extensive rural water supply program, a "three-tier" system has been developed Box Table 3.2A Cost Data on for maintenance of the India Mark il handpump. By Handpump Maintenance the end of 1982, there were some 150,000 Mark Ils in operation in 14 Indian States (the figure is now , approaching one million), and the Government of Madhya Tamil India, with support from UNICEF, sponsored a survey Orissa Pradhesh Nadu Rajasthan on the effectiveness of maintenance in four states - __ Orissa, Madhya Pradesh, Tamil Nadu and Rajasthan. Pumpcost The results, published in 1984, showed distinct (US$) 270 280 379 N.A. variations from one state to another, and provided valuable information about the targets which were Maintenance Motorized Block Block Private feasible in operation of the three-tier system. system mobile mechanic mechanic mechanic The aim is that a village pump caretaker should team team mechanic be responsible for routine maintenance of a single handpump (Tier 1); a "block mechanic" (in India a Percentofpumps "block" refers to a large area with several villages) working 95 98 78 75 with specialist skills and tools should be responsible for more complex maintenance and most repairs, with Annual recurrent responsibility for 50-60 pumps (Tier 2); and a mobile cost (US$, 1984)a team at the district level should be on hand for major repairs calling for transport of heavy parts or lifting Labor- local 12 43 21 lob gear. The mobile teams should cover about 500 Transport 6 13 11 pumps (Tier 3). The system was developed following Pump spares 21 9 5 5 surveys in the early 1970s, which had revealed that Othercosts 1 2 as many as 75% of handpumps installed in India were Total 40 67 37 - out of operation at any given time. Cost per capitaC 0.20 0.34 0.19 The 1984 results were much more encouraging (Box Table 3.2A), with the number of pumps out of commission in the sample ranging from 25% in Notes: a. Overheads not included. b. Amount allo- Rajasthan to just 2% in Madhya Pradesh. cated by PHED to Rural Development and Panchayat. Unfortunately, cost information is sparse, particularly c. Based on 200 people per pump. in relation to transport - usually the most expensive lB Area Mechanic as the one in West Africa described in Box 3.1, repairs The community may contract a mechanic from nearby to are effectively organized under community fix the pump, paying for the service through a management. In other projects, the area mechanic is maintenance fund. A typical example involves the responsible to the government water authority, as in employment of a repairman with a bicycle who lives Malawi (Box 3.3). A similar arrangement exists in India locally and services handpumps in a number of (Box 3.2), though in some States local government units surrounding communities. This system reduces the need involving groups of communities are beginning to for simplicity of the pump to some degree (the repairman assume responsibility for maintenance with a continued can be expected to carry a tool kit and to have better subsidy from State or central government. mechanical skills), but lightness and ready availability of spares are still important requirements of handpump 2. Central Management of Maintenance design. While maintenance carried out by a village caretaker A governmental or other agency maintains the is still relatively rare, area-mechanic maintenance has handpumps, with mobile teams travelling from base gained rapid popularity in recent years, and constitutes camps to carry out repairs. There are two types of such a substantial improvement both in cost and in the maintenance, depending on whether the community reliability of the service provided. In some projects, such participates in maintenance activities. 34 element of any system which depends on mobile The fourth survey area was Amjer District in teams. However, the data provide illustrative Rajasthan, where a single level "one-tier system" had comparisons of different versions of the planned been implemented by training a number of private maintenance system (see Box Table 3.2A). sector mechanics to carry out pump maintenance and In Orissa, Mayurbhanj District was the first to repairs, on the basis of about 30 pumps per mechanic. introduce the three-tier system and it was not fully At the time of the survey, about half of the repairs operational at the time of the survey. The 2,700 were actually being carried out by the private pump pumps were being maintained by three mobile units repair mechanics paid by the Panchayat with funds (900 pumps per unit) under the control of the Public transferred from the PHED. Not all of the mechanics Health Engineering and Municipal Works Department were being paid and several had left their jobs for (PHED). Block mechanics had not been established other occupations. PHED block mechanics were carr- and pump caretakers had been appointed in less than ying out most of the repairs on the remaining pumps, half of the blocks surveyed. The survey found that with a few being repaired privately. Overall, 75% of the 95% of the pumps were working, but noted that 80% pumps surveyed were working satisfactorily, but the were less than four years old. average downtime of one month was considered by In the Jabhua District of Madhya Pradesh, 36 the investigators to be too long a response time. block mechanics and three mobile units looked after One important conclusion from the survey is that 2,130 pumps. No pump caretakers had been app- local block mechanics can maintain India Mark II ointed in the survey area. Again, a high proportion of handpumps, while depending on mobile teams only for the pumps (85%) were less than four years old, and in extraordinary repairs. By basing the maintenance sys- this case 98% of the pumps were working. In Tamil tem on local mechanics, vehicle costs can be consid- Nadu, the survey was conducted in Tirunevelli erably reduced, and the overall recurrent costs District, where over 95% of the maintenance on 3,210 brought down to affordable levels. Pump caretakers pumps was carried out by 31 block mechanics (104 were not found to be effective for carrying out main- pumps per mechanic). There were four mobile teams, tenance. Lacking tools, grease, materials, etc, and each responsible for 800 pumps and pump with no financial incentives, they had little interest in caretakers had been appointed for three-quarters of the upkeep of their pumps, though their role remains the pumps, but their duties were limited to reporting important as a means of contacting the mechanics breakdowns. Half of the pumps were more than 4 when breakdowns occur. Indeed, the survey noted a years old and the survey found that 78% were lack of any commitment by local communities towards operating. Since 1982, responsibility for maintenance pump maintenance, and attributed this in part to the has been transferred from the PHED to the Govern- absence of any financial contribution being required ment's local administrative units (Panchayat Unions). from the community towards pump maintenance. 2A Central Maintenance with surrounds. As with System 1, the Project recommends Community Involvement that such caretakers should be paid, and that the Responsibility for carrying out and financing operation community has an organization (e.g. a water committee) and maintenance is divided between the community and responsible for funds collection and other management an external agency - usually the government water activities. Major repairs are usually the responsibility of authority, but sometimes a parastatal, donor or non- the external agency, which pays the repair teams and governmental organization. This division of provides the spare parts. responsibilities is specified in an agreement settled in A degree of community participation has also made discussions with community leaders in the planning it possible in some projects to dispense with, or phase of the project. Pump maintenance is managed by considerably reduce, the use of motor vehicles. Instead, the external agency, with the community accepting government mechanics are located in areas where each certain responsibilities as part of its contribution to the can service a number of pumps (from 15 to 100 or more). scheme. These mechanics, together with village caretakers, have The arrangement will typically involve a designated been able to repair pumps in countries such as India and handpump caretaker within the community undertaking Malawi (Boxes 3.2 and 3.3), using only a bicycle to travel some preventive maintenance and probably simple between pumps and to transport tools and spares. repairs, commonly limited to the pumphead and This form of maintenance has been coming into HANDPUMP PROJECT PLANNING AND IMPLEMENTATION 35 Box 3.3 Community Involvement in Malawi's Integrated Rural Water Supply The Livulezi Rural Water Supply Project in Malawi has the stores held by the two mechanics. When moni- a number of interesting features, which have helped toring ends, other arrangements will have to be found to keep down costs and promote reliable functioning: for supplying spare parts to the Livulezi project area. Another problem, already becoming apparent, is * Wells were only drilled if hand-dug wells could not funding for centralized procurement of spare parts. be constructed at the particular location. The Malawi government does not presently seek any Wherever feasible, existing wells were rehabili- payments from villagers for recurrent costs. tated and, in the case of dug wells, protected. Assuming that the wells have a life of 20 years * Drilling extended only far enough to obtain a flow and the pumps a life of 10 years, and with interest at into the well to support the discharge for a hand- 10%, the annualized cost of handpumps and drilled pump. This usually meant that depths were wells at Livulezi is about $207 per pump, including restricted to 20-30 meters, most of it through capital and maintenance. This amounts to $0.83 per weathered rock; little penetration was needed capitaperyearforthe250usersperpump. into basement rock. * The cable tool rigs which were used had belonged to the government for more than 15 years, and Box Table 3.3A Capital Costs of their costs were fully depreciated. Livulezi Wells (US$) * Drilling and dug-well construction were integrated in clearly defined projects, allowing greater prod- Drilled well Dug well uction, effective supervision, and lower costs. Direct costs pluspump plus pump * Most wells were equipped with handpumps Materals 300 280 produced in Malawi to alleviate the problems Labor 70 20 associated with imported spare parts; the pumps Subtotal 370 300 were designed for village-level maintenance. Indirect costs * Maintenance of the handpumps is decentralized. Camp 180 150 A village caretaker was appointed for each pump Transport 260 210 and is responsible for simple maintenance. Break- Other 130 60 downs are reported to one of two government- Subtotal 570 420 trained mechanics, each equipped with a bicycle Total well costs 940 720 and living in the project area. The villagers Pump and Apron (estimate) 450 a themselves assist in transporting the tools to the Total Cost 1,390 720 pump and help the local mechanic with repairs. * Costs of construction and maintenance have No. of people served 250 125 been recorded throughout the project. Cost per person $5.56 $5.75 Drilled wells were constructed by the Department of Note: Costs are averaged over 96 drilled wells and 42 Lands, Valuation and Water (DLVW). The community dug wells. They are based on 1982 prices in Malawi participated in site location as well as construction. Kwatcha converted to US$ and adjusted to 1985 Design criteria were: 27 liters per head per day; a . . maximum walking distance of 500 meters; and a Box Table 3.3B Maintenance maximum of 125 people served by a dug well and 250 Costs of Wells people served by a drilled well. The completed - , Livulezi Integrated Project consists of 200 wells Annualcost Annualcost (including rehabilitated wells), which serve almost perpump perperson 50,000 people. Its success led to similar integrated Direct costs projects in other parts of Malawi, and in other Spare parts 2.84 0.01 countries. Maintenance staff 4.64 0.02 At present, logistical support for the supply of Subtotal 7.48 0.03 spare parts depends in large measure on the United Indirectfcosts Nations Volunteer, an engineer employed by the Transport 6.22 0.03 Handpumps Project, whose main job is recording the Subtotal 16.42 0.07 performance of pumps being monitored in the field trials. Having a pick-up truck at his disposal, he has Total $23.90 $0.10 also been transporting spare parts and restocking _ 36 popular use since the beginning of the 1980s, and there unity level, the fact that control is in the hands of an are many encouraging success stories. Costs are lower outside agency means that there is no sense of owner- than those of System 2B, where all maintenance is ship of the handpump system. Misuse and vandalism of carried out by the external authority. It is also more pumps occasionally occur, leading to a vicious circle of readily achievable in political terms in many developing failure and unreliability. countries than immediate village-level management of maintenance, and can serve as a transitional form of Maintenance Strategies maintenance until the community can assume full responsibility under System 1 A or 1 B. Until recently, the heavy construction and complex main- The distinction between this arrangement and tenance routines of most handpumps demanded skilled System 1 B is that these area mechanics are managed mechanics, numerous tools and lifting equipment, so and funded by the agency, with little chance of full central maintenance was the only practical option. recovery of maintenance costs from the community. The Development of lighter, simpler handpumps has made it long-term sustainability of such an arrangement is easier to pass some responsibility to the community, therefore questionable. A major disadvantage too is that and to move towards area-mechanic maintenance, with policy changes or budgetary restrictions could reduce significant reductions in cost and improvements in the effectiveness of maintenance activities, even when reliability. the community is paying in full, if control of the funds Whichever maintenance system is in operation, rests with the government. several possible maintenance strategies are available. Breakdown repair remains the most common approach 2B Central Maintenance where central maintenance applies; limited preventive This remains the most common form of handpump maintenance is frequently adopted alongside breakdown maintenance and will continue to be needed for the more repair when the community is involved in maintenance complex and heavy handpump types and for deep pump activities, and some central maintenance systems settings. The usual form consists of a public sector include routine inspections and preventive maintenance; organization managing mobile (district) maintenance there is virtually no evidence of scheduled servicing of teams strategically located across the region. The handpumps under any of the maintenance systems. teams report to a regional or national headquarters which A strategy based solely on response to breakdowns handles overall budgets and spare parts procurement or serious drop in performance may lead to unnecessary and distribution. Each team includes skilled workers damage to other parts of the equipment, and more equipped with special tools and a motor vehicle (some- expense in the end. A good example in the case of hand- times a large truck with a crane). Handpumps are visited pumps is bearing wear, a progressive effect leading to when the community reports a breakdown or, in excep- gradual reduction in performance. Left to deteriorate tional cases, according to a regular maintenance until the pump becomes unusable, the resulting play in schedule. the pump handle can cause serious, sometimes irrep- High cost and poor service are generally associated arable pumphead damage. Even the limited preventive with the system, because: maintenance in which community members lubricate moving parts and tighten loose bolts can have a * direct costs of vehicles are typically 50% or more of significant impact, by red,ucing the number of break- the total costs of mobile maintenance teams; downs and spotting the need for repair in good time. * vehicle breakdowns result in long delays in respon- The Community ding to reported handpump maintenance needs; Most communities in developing countries need assis- * transport management in the public sector is tance with the construction and maintenance of wells difficult, and the use of vehicles for other purposes with handpumps, but they must be encouraged to than handpump maintenance may further increase participate to the maximum extent possible. Too often, costs and downtime. an improved water supply has been seen as a free service that the government must provide to improve the In many countries where it has been introduced, life of its citizens. While many communities may need central maintenance has a poor record, with response financial help, relegation of their role to that of recipients time between reported breakdown and actual repair without significant participation has often resulted in an sometimes stretching to several months. At the comm- inappropriate choice of technology and service level, wrong location of the water point, unnecessarily high F cost, inability to keep the scheme operating, and "In many countries where it has ultimately user rejection. Community participation that is been introduced, central limited to contribution of free labor results in nothing ueen mirouuceu, cengra, more than a small cost saving, without addressing other maintenance has a poor crucial issues. Strong community initiative is essential record.. for the successful long-term maintenance of hand- .__________________ ...________________________ pumps, and to achieve it, community members must be HANDPUMP PROJECT PLANNING AND IMPLEMENTATION 37 intimately involved right from the planning stage. In some countries (e.g. China and Guatemala), this has been standard practice; others have recognized the need for community involvement and are experimenting with ways of increasing it. The following recommen- M a dations are based on experience gained in the course of the Project field trials, and on a wealth of information - gleaned from other projects. Much of what is said is geared primarily to African conditions, as the need to promote stronger community involvement is generally greatest there, but the principles apply to all developing countries. How then should one go about establishing comm- unity management of a village water supply system? g .-' - - a) The institutional capacity of the community Users have lined up some 150 water jugs while waiting to use this Volanta pump in Burkina Faso. Long queues are common in must be evaluated. Organizational experience may be areas such as the Sahel in Africa, where drilling costs are high, apparent from the existence of self-help groups, coop- and user groups must be large to spread the costs. But service eratives, etc., but the strength of the leadership must be level has to be assessed carefully, as intensively used pumps assessed, along with the level of education and skill. For willbreakdownmorefrequentlyandberejectedbyusers. many communities, an improved water supply will be the first time that social structures have had to adapt to the of different service levels will be the value of time spent management of a service that combines organizational, queuing and hauling water. Thus the service level for a technical and financial skills. handpump project relates to the number of people Handpumped water supplies lend themselves to served from each pump and the walking distance to the maintenance by user communities with very limited tech- pump. As will be apparent in the discussion of pump nical knowledge. Nevertheless, the needs are real and technology later, the daily output is controlled by several must be defined and catered for if the scheme is to be factors, the most significant being the pumping lift. reliably maintained. There are thus practical limits to the number of people A water committee may grow to form a focus within who can obtain water from one pump, which vary with the the community for other development activities - depth of the water table. including an eventual upgrading of the water supply. The more people served by each pump, the longer will be the queues and the greater the risk that people will b) The demand for water supplies has to be estab- return to alternative traditional sources. Pump break- lished. Here, demand is taken to mean the amount of down frequencies are also directly related to hours of water households want to obtain each day, once they pumping, so that greater intensity of pump use will mean are aware of the price, including any cash amount that more frequent needs for maintenance or repair. On the has to be paid and the time which will be taken up by other hand, particularly where drilling costs are high, it queuing and hauling. It is still common for an external will be necessary to spread the cost of each installation agency or government planner to determine in advance among as many users as possible. In the end, the what water demand will be and to set the number of water number of wells to be provided and their location has to points according to some predetermined formula. Such reflect the community's needs and desires, and this projects have limited chance of success. Unless the decision will have to be based on financial and technical community is aware in advance of the alternatives avail- information prepared by specialists from the sponsoring able and the costs and benefits of each, there will be government agency. hardly any sense of ownership and little prospect of the The availability of alternative water sources will community assuming the responsibility to manage the have a major influence on the number of handpumps that new system. must be installed to provide an acceptable improved Demand for water from handpumps may be low if level of service. In Bangladesh, for example, where alternative sources are easily accessible, and if these surface water is often readily available near the home, it existing sources are unprotected, health education may has been found that a typical handpump should serve no be needed to convince community members of the value more than about 75 people, or many will choose to use of safe water. There may also be demand for water for nearer, polluted sources. By contrast, in southwest other than household uses, such as livestock watering Sudan and in northern Nigeria, where during the dry and small-plot irrigation. It is important that the season people must often walk several kilometers to community should take the decision itself on how much obtain water and must then wait in long queues at the water is needed. source, one well and handpump can be located to serve as many as 250-300 people. c) Closely linked to the demand for water is the The smaller user group per handpump is affordable service level to be provided by the new system. Part in Bangladesh because wells can be sunk by the of the community's evaluation of the costs and benefits "sludger" method at a cost of US$100-200 per well (exc- 38 luding the price of the pump). In India, where wells cost ment can improve the chances of the scheme being about US$2,000, service levels of about 125 persons properly maintained by organizing refresher courses for per pump are practical, but in West Africa, much larger caretakers, and by encouraging the community to pro- user groups are typically necessary to spread the high vide incentives to repairers. drilling costs (US$4,000-20,000) over more users and so The period of project construction provides an reduce the per capita cost. excellent opportunity for training in the skills necessary for the subsequent upkeep of the system. Qualified d) The willingness of the community to make a finan- trainers from the implementing agency, supported if cial contribution - in line with its ability to pay - has necessary by representatives of the pump supplier, can to be assessed. One promising mechanism increasingly take advantage of the community interest in project acti- being used is for the community to be asked to make a vities to organize demonstrations of pump installation material commitment (e.g. to collect enough money to and maintenance, particularly for those selected by the cover the first year's maintenance), before any decision communityto care forthe pump. is taken to start drilling. When deciding on the number of pumps to be installed, a balance must be struck between what the sponsoring agency pays and what the comm- The Aquiferl unity pays. As a minimum, the community should pay operation and maintenance costs in full for a level of Accessible groundwater exists under more than three- service that offers a basic improvement (such as a well quarters of the earth's surface, but knowledge of its with a handpump), and should also be responsible for the local characteristics (hydrogeology) is often sparse. full incremental cost of any higher service level. Some engineers have preferred to develop surface water resources because they have a better understanding of e) Defining the boundary between activities for which the hydrology. For the reasons outlined in Chapter 2, the community can reasonably assume responsibility analysis will normally lead to selection of groundwater and those which should be part of the public sector's rather than surface water development, and planners are role is difficult but important. The government water urged to undertake the necessary studies and surveys agency is almost inevitably stretched to provide support to gather full information about aquifer potential before services at the community level, while the range of skills embarking on community water supply programs. and equipment available to pump caretakers is likely to Though handpumps draw comparatively small be small. Difficulties arise when the community depends amounts of water from the aquifer, their effectiveness on outside help for all maintenance and repair work, and reliability can be significantly influenced by proper because centralized maintenance is expensive and at consideration of local groundwater conditions. Problems times difficult to manage. If the community takes full typically arise when designers fail to recognize sea- responsibility, the danger is that spares, tools or skilled sonal movements in the water table or competing people may be absent when major breakdowns occur. demands from irrigation pumps, or when low-yielding Increasingly, private mechanics are providing the aquifers are developed without allowance being made for critical bridge between the limits of the water agency's the drawdown which will arise during pumping, or when management capabilities, and the community's skills. the chemical quality of the water makes it unpala- Box 3.1 demonstrates well how the mutual interests of table orcorrosive. community members and private sector mechanics keep Any large scale national or regional community water the water flowing at affordable cost. supply program should include preparatory groundwater Improved water supplies are necessary but not studies and continuous monitoring and record keeping. sufficient to bring health benefits. It is the complemen- Much knowledge can be gained from existing well const- tarity of safe water, proper sanitation and good hygiene ruction projects, if data on water depth and pumping practice that is the basis of the International Drinking rates is kept systematically. Increasing knowledge of Water Supply and Sanitation Decade action plans. hydrogeology will pay back the initial investment very Health educators must ensure that communities benefit- quickly through more effective projects and avoidance ting from new water schemes understand the principles of misguided developments. of disease transmission and are encouraged to improve The amount of information about groundwater nee- sanitation practices and construct latrines where ded to ensure reliable designs for handpump schemes necessary. varies considerably from region to region. No extensive The government water agency may have an impor- studies are needed to show that the vast groundwater tant role in health education and training specifi- reservoirs of the Indus and Ganges basins can support cally directed at water supply and sanitation system community water supplies. In contrast, detailed geophy- management. Commitments in these fields should be sical exploration may be necessary before effective recognized at the planning stage and instituted before schemes can be designed for many areas of Africa and construction starts. If missing community skills can be created through training programs implemented before and during construction, the goal of community manage- 1. An aquifer is a stratum or zone below the earth's surface ment will be much easier to achieve. After responsibility which yields groundwater to a well in sufficient quantities for the has been handed over to the community, the govern- required use (water supply, irrigation, etc.). HANDPUMP PROJECT PLANNING AND IMPLEMENTATION 39 advertised as suitable for pumping lifts as high as 100 meters, experiences during the Project confirm that handpumps should not be installed at heads greater than 60 meters, because their performance and reliability at those depths have not been established. Any pumping ______1 \=GR,roand khead over 45 meters must be considered to be very high, as, even at that depth, discharge will be low for an accep- table pumping effort and maintenance will be difficult. in permeable aquifers the pumping water level will be little different from the static water level, but in low-yielding aquifers drawdown of many meters may occur, resulting Pumping lift in high pumping heads and consequently lower delivery rates. Static water level (SWL) Handpump withdrawals alone will rarely lead to ____ ____ ___ seasonallyvariable) depletion of groundwater resources. Even in low rainfall areas, natural groundwater recharge is almost invariably enough to replenish the aquifer. But there are other dan- gers. Motorized pumps providing irrigation supplies may Pumpingwaterlevel(PWL) cause nearby wells with handpumps to run dry because of big drawdown effects in the vicinity of the well. In the longer term, widespread and indiscriminate motorized pumping may lead to "mining" of the groundwater and a Well depth progressive lowering of the water table. As well as (after sand,infiltration, if any) causing environmental damage (e.g. land subsidence, Origina well depth loss of trees and vegetation, saline intrusion), such over- exploitation of groundwater may render low-lift hand- In an unconfined aquifer, the static water level in the well pump systems useless if the water falls below their (without pumping) is the level of the groundwater table. After the operating limits (Box 3.4 quotes an example from pump has been used for some time, the water level in the well will Bangladesh, where suction pumps were put out of use sink to the pumping (or dynamic) water level. The difference by widespread withdrawals for irrigation). between the two levels depends mainly on the rate of pumping, Community water supply programs may involve the the length of time the pump has been used, and the permeability drilling of tens of thousands of wells (hundreds of of the aquifer (the rate at which the porous medium transmits thousands in the case of India or China). We have seen water). The pumping lift is the distance between the dynamic in Chapter 2 that handpump projects are easily upgraded water level and the discharge point, though for convenience itis and that movement to an affordable higher service level normally regarded as the depth of the dynamic water level below is to be een t h an one preve futur the ground sufface. is to be encouraged. How then can one prevent future developments from undermining the widespread benefits brought by the initial handpump projects? India, where suitable aquifers can exist as small isolated Regulation of groundwater exploitation is important weathered pockets in crystalline basement rocks such to any country, and legislation to control groundwater as gneisses and granites. withdrawals adds strength to community water supply A full groundwater management strategy involves strategies. Licensing of wells and approval of pump surveys to locate the water-bearing strata, use of types and discharges may be administratively difficult, special techniques to define the aquifer geometry but uncontrolled exploitation of aquifers is an expensive (area and depth) and determine its capacity (reliable price to pay for inaction. yield) and water quality, development of measures to In planning handpump programs, the potential for regulate its exploitation and ensure its protection upgrading should be an important consideration. If early from contamination, and design of suitable methods of upgrading seems practical, deeper or larger diameter groundwater withdrawal. drilling in the handpump phase will normally be more For handpump projects, knowledge of the aquifer economic than further drilling to accommodate motor geometry and its capacity may limit the degree to which pumps later. Well testing during construction of early the community can participate in the selection of well projects and groundwater monitoring over time will sites, but will have the compensating benefit of reducing provide data for long-term planning and may indicate that the number of costly or non-productive wells. Yields limits have to be imposed on future service levels and greater than 0.2 liters/sec are enough for handpumps, irrigation supplies if the resource is to be used equitably. which means that many areas of the world underlain by Regular groundwater monitoring has been introduced relatively impermeable rocks not generally regarded as on several projects in West Africa and is a simple and potential groundwater sources can be suitable if the right effective operation which should be implemented for all service level is chosen. important aquifers. One crucial constraint on the use of handpumps is As well as protecting the aquifer from excessive the pumping lift or head. While some handpumps are withdrawals, legislation may be needed to safeguard 40 Box 3.4 Bangladesh: Motorized Pumping Threatens Suction Handpumps In many ways, Bangladesh is the ideal location for ex- 1970 to 1983 reveals that water tables dropped tempo- tensive groundwater development. The vast deltaic rarily below 8 meters at some time during that period plain consists of fertile alluvial soils overlying a over 10% of the area in which groundwater is used for groundwater resource replenished each year by an irrigation. That means that between 50,000 and average of 2,000mm of rainfall and the widespread 100,000 village handpumps are at risk of drying up for annual flooding of the Ganges and Brahmaputra as much as 3 months of the pre-monsoon season rivers. The geology makes it easy to drill wells quickly each year. And a similar proportion of farmers using and cheaply, while the shallow water table has encou- shallow tubewells are in the same position. raged a proliferation of suction handpumps to provide For the farmers, the problem can be rectified by millions of rural people with low-cost clean water digging a 2-3 meter deep pit and lowering the portable supplies for domestic use and small irrigation. motorized pump. Villagers depending on suction hand- However, in recent years, unregulated motorized pumps for clean water have no such option, as the pumping for irrigation is thought to be a major factor in pumps are not designed for forcing the water the the lowering of the groundwater table, which is neces- additional distance to the surface. They may be able sitating a new approach. Since the 1970s, the Depart- to obtain supplies from the nearby irrigation pump, or, ment of Public Health Engineering (DPHE), with more likely, return to the previous unsafe surface substantial support from UNICEF, has promoted and sources, in an environment where the risk of contrac- implemented a village water supply program based on ting cholera or other diarrheal diseases is high. the use of locally manufactured suction handpumps. Future handpump projects in areas of Bangladesh The program was very successful and by the mid where the groundwater level is falling have a new 1980s there were more than 800,000 such hand- technological option in the form of the Tara pump. This pumps in use, all capable of lifting from a water table direct action handpump (Box 4.7 in Chapter 4) has no more than 7 meters below ground. been specially developed for local manufacture and Irrigation development has also been rapid, with village-level maintenance, and can lift water from 12 to an early emphasis on deep, high-production pumps 15 meter depths. (200 cu m/hour), giving way in the late 1970s to so- In Bangladesh, the technical solution is probably called "shallow tubewells" from which centrifugal preferable to the legislative one, as regulations pumps with surface-mounted diesel engines deliver controlling groundwater withdrawals for irrigation 25-30 cu m/hour. There are estimated to be more than would be difficult to implement in an equitable way and 100,000 of these in operation throughout Bangla- would interfere with the important goal of increasing desh. About 300,000 privately-owned handpumps are agricultural production. also thought to be in use for both drinking water and Few, if any, countries have such immense ground- irrigation purposes. water resources as Bangladesh, and the experience The heavy irrigation pumping in the dry season there with suction pumps is an important warning to all undoubtedly contributes to the rapid lowering of the designers contemplating the use of such pumps. Full groundwater table during that season. The ground- account must be taken of competing demands on water is then replenished in the rainy season and the local groundwater resources when estimating draw- water table rises again. Groundwater monitoring from down and therefore maximum seasonal pumping lift. groundwater quality. Industrial nations provide affect taste or color, making the water unpalatable or ample evidence of damage to precious groundwater. aesthetically unacceptable (high iron levels are not Industrial effluent, landfill waste disposal, accidental uncommon and will impart a bitter taste and stain food chemical spillage, excessive application of fertilizers, and laundry; sulfates can give an unpleasant smell and and use of pesticides, are all inexorably reducing the have a mildly laxative effect; and salinity levels may quality of groundwater and threatening present and sometimes be too high for palatability). Groundwater future drinking water supplies. In most developing coun- may also be corrosive, and this can have a considerable tries, the risks are presently not so great, but the impact on pump breakdown rates, when corrodible warnings should be noted in time. In particular, sanit- components like mild steel pumprods and rising mains ation program planning must ensure that latrines are are attacked (corrosion problems are discussed in more sited in such a way that they do not endanger shallow detail in Chapter 4). aquifers. Water quality problems such as high iron or fluoride Groundwater quality is important for several levels can be overcome through treatment, but this will reasons. Some naturally occurring salts, like fluorides, be costly and demand greater institutional strength can make the water injurious to health. Other salts may because of the more complex management involved. HANDPUMP PROJECT PLANNING AND IMPLEMENTATION 41 Box 3.5 Some Drilling Methods for Handpump Wells The largest single cost item in a handpump-based under consideration. Box Table 3.5A lists some of community water supply (CWS) program is almost the more commonly used drilling rig types, indicating invariably the well drilling. Correct choice of drilling their cost ranges and operational needs, as well as method can have a considerable impact on overall their drilling capabilities. costs and thus on the service level (number of Though the waterwell drilling market is large, few pumps) which can be provided, drilling rigs have been specially designed for the Available drilling equipment covers a wide range. application. The range available is mainly dictated by The drilling rig itself may cost as much as the needs of mineral exploration or mining. For US$500,000 for a large multipurpose rotary rig, or as handpump projects, drilling demands are little as US$1,000 for a simple hand-operated device comparatively light. Simplicity, curability and capable of drilling shallow wells in soft ground. As well maneuvrability are often important criteria, alongside as varying in price and capabilities, different drilling cost. rigs call for widely varying skills and backup support if The drilling duties specified in Box Table 3.5A they are to perform efficiently. cover most situations likely to arise on CWS programs Selection of the right equipment depends very in developing countries. Many schemes involve only much on local geology and anticipated drilling depths, shallow wells (15 meters deep or less) in but it is also important to recognize the constraints unconsolidated ground; few require drilling beyond 80 imposed by operational requirements for the rigs meters. In hard consolidated rock, the well diameter Box Table 3.5A Cost Comparisons for Different Technologies Hand digging Hand-operated Cable-tool Small air-flush Multi-purpose rig rig rotary rig rotary rig Approx. capital cost range in US$ $1,000 $1,000-5,000 $20,000-100,000 $1 00,000-250,000 $200,000-500,000 Running cost very low low low medium very high Training needs for operation very low low low-medium medium very high Repair skills very low low low-medium medium very high Back-up support very low low low-medium medium very high Approx. range of penetration rates in meters per 8-hr day 0. 1-2.Om 1-15m I-Ism 20-1lOOm 20-lOO0m 200mm* holes to 1 5m in unconsolidated formation -f ast fast impossible very fastt 200mm* holes to 5Om in unconsolidated formation -slowanddifficult fairly fast impossible very fastt 200mm* holes to 1 5/50m in semi-consolidated formation -impossible fairly fast impossible very fastt 1 00mm holes to 1 5/50m in consolidated (hard) formation (not gravel packed). -impossible very slow very f astt very fastt *200mm holes to give 1 00mm diameter f inished well after screening and gravel packing. t Constrained by logistical support. 42 can be restricted to the 100mm needed to accom- depth of 80 meters. Any capabilities beyond those modate a handpump cylinder, while in unconsolidated minimum requirements which make the rig more formations, allowance for casing and gravel pack will costly, more cumbersome, or more difficult to operate mean a diameter of 200-250mm. are undesirable. The ideal drilling rig would therefore perform In the absence of a purpose-designed rig for CWS quickly and efficiently drilling 200-250mm diameter work, the choice is inevitably a compromise. As an holes in soft rock and 100mm diameter holes in hard approximate guide to selection, the following notes rock - sometimes in the same well - to a maximum amplify remarks in Box Table 3.5A. operators. Effective in unconsolidated or semi- consolidated formations down to about 50 meters, they can offer considerable cost savings and other benefits when compared with rotary rigs. However, cable-tool rigs are not suitable for hard-rock drilling. Small air-flush rotary rigs ; / XSpecifically designed for drilling small diameter holes quickly in hard rock, small rotary rigs are restricted to wells which will not require gravel packing. Even then, the need for a mechanically complex compressor can a - 4- be a handicap for CWS work. In the hands of a capable drilling contractor, these rigs can, however, be very effective. Hand-operated drilling equipment Simple, inexpensive and highly maneuvrable, hand drilling may be the most appropriate choice for shallow wells down to 15-20 meters. Beyond 20 - meters, hand drilling becomes very difficult, and , progress is inevitably slow. One apparent advantage k L -the lack of any mechanical equipment which requires servicing - is less significant than it first - , , - appears if the equipment has to be carried from well L.- to well by motor vehicle, as the servicing needs of a . , light cable-tool rig are usually less than those of a - -- motor vehicle. |S f_- Multipurpose rotary rigs Massively over-designed for CWS work and , 0 ,i j.correspondingly expensive and complex to operate and maintain, large rigs are often provided by donors *_-X . on the basis of rated performance which cannot be reproduced under field conditions. Limited maneuvrability means that they are regularly bogged down on rural roads, and manning and servicing the L->-- ^ - - 9 sophisticated rigs often proves difficult for water E; . ._agencies in developing countries. Though restricted choice may point to selection of these expensive Cable-tool rigs machines, a smaller rotary rig for hard-rock drilling, An old and simple design which has changed little a cable-tool rig for semi-consolidated rock drilling, or over the years. Cable-tool rigs are generally durable hand-operated equipment for shallow-well drilling in and easy to service, requiring only minimally trained soft formations, are all likely to be more appropriate. HANDPUMP PROJECT PLANNING AND IMPLEMENTATION 43 The Well ground should be avoided to reduce pumping heads, and sites should preferably be chosen away from (ideally up- The long-term reliability of a handpump project depends gradient of) pollution threats such as latrines or cattle to a great extent on the wells through which the pumps stockades. Here, the advisers must explain the prin- draw the groundwater. Analysis of breakdowns during ciples of selection to the water committee, including if the Project field trials demonstrates beyond doubt that necessary making strong recommendations against even a well-designed and carefully selected handpump certain sites on technical grounds. Ideally, it is the may not perform satisfactorily if it is installed on a badly committee which must make the final decision, and only constructed well. Sand entering pumping elements leads if the scheme is technically or economically impossible, to rapid deterioration of valves and seals, calling for should the community's wishes be overruled. frequent repair and replacement and disenchantment The most difficult situation arises in some of the among users. semi-arid areas of Africa and elsewhere, where the Usually the most costly part of a community water weathered profile is thin and groundwater is found in scheme, wells can be designed to protect the hand- fractures within the unweathered rock. Geophysical pumps from damage and to ensure that the potential of surveys may be the only way to locate adequate the aquifer is fully realized. Too often, however, prom- resources, and a distance of only 10 meters might make oters presume that any hole in the ground will suffice for the difference between a productive well and a dry one. a handpump, with the result that digging or drilling costs Here, the selection procedure is different, with the are wasted because the pump will perform poorly on the community first identifying desirable and undesirable resulting well. areas and the 'echnologikts then finding the optimum Water wells divide into two categories: dug wells; drilling points within the chosen areas. and drilled wells, and each category may then be subdivided according to whether the well is constructed The next important consideration will be well depth. by hand or by machine. For definition purposes, a dug Wells must be deep enough to ensure reliable supplies well is a well that a person can enter to clean or deepen even during prolonged droughts. The Project encoun- and will rarely be less than 800mm in diameter. tered very serious problems due to wells drying up in the Handpumps can be installed in dug wells or drilled long dry periods of the early 1980s in Africa. Over half of wells of any depth and diameter, subject only to the the wells in one large community water supply program practical limit that the pumping water level should became unreliable during the driest spells, when water normally not be more than 45 meters down (60 meters in levels fell 5 meters or more below their seasonal average exceptional cases, if other pumping options are not levels. feasible). Detailed discussion of actual construction Ensuring that drilled well depths are adequate is rela- methods for water wells is beyond the scope of this tively simple, as drilling commonly proceeds 15 meters report, though the merits of alternative digging and or more below static water levels to achieve sufficient drilling techniques are referred to briefly in this chapter flow of water into the well. Dug wells are a bigger prob- and some examples are given in Box 3.5. lem. Dewatering during construction is difficult, and dug Aspects of well design and construction which can wells usually penetrate only a short way below the static influence handpump system performance are: siting, water table, relying on well storage fed by percolation depth, screen design, development, and apron design. during the night to meet daily needs. Such wells are of course the first to dry out when the water table drops. Well siting is a good example of the way that the With traditional open wells, the answer is simply to advisers and the community need to share knowledge dig deeper when the need arises. The same principle and opinions. Too often, a drilled well is sited purely on should be applied to dug wells fitted with handpumps. the basis of a geophysical survey, irrespective of the Covered access openings must be provided into the community's wishes. A common result is that few people well, and must include an adequate seal against surface make use of the new facility, regardirig it as inconvenient contamination. There is a double benefit, as the access and imposed from outside. openings provide a backup means of drawing water by There are many cases in alluvial plains, where the bucket if the handpump breaks down and cannot be community can have full freedom of choice in locating its repaired quickly. wells. In Bangladesh, for instance, groundwater is ubi- Particularly with drilled wells, there is a balance to be quitous and plentiful, and hand drilling to sandy horizons struck between extra reliability and cost. Drilling is an protected from pollution by overlying clays offers an expensive operation in many parts of the world, and almost guaranteed success. In these circumstances, making excessive allowance for drawdown of the water householders generally choose to site wells in their bari table may lead to waste of resources. Again, knowledge (hamlet), next to their homes and the ideal hydrogeology of the local hydrogeology and planned irrigation develop- of the region means that costs are low and risks are few ments can lead to substantial savings, and the value of (unless the well is directly adjacent to a latrine). record keeping on all projects cannot be stressed too Technical advice becomes necessary in situations highly. like the deeply weathered basement areas of central Africa, where adequate quantities of groundwater can be Preveritirrg sand entry into the well is the next task of expected almost everywhere, but excessively high the well designer. The problem relates mainly to drilled wells; lining and support of a dug well is often important Frequently the new pump becomes a focus of community to prevent infill or even collapse, but it is less common life. Its amenity value can be enhanced by adding for sand movement to be a threat to water quality or clothes washing and bathing facilities. Many villages, en- pump components in large diameter wells. It is, however, couraged and helped by government extension workers, as has already been mentioned, a major cause of hand- divert drainage water from the apron to irrigate a small pump breakdown in poorly designed and developed vegetable plot. The appearance of the pump and its drilled wells. surrounding apron can be a useful guide to a comm- It is frustrating for handpump specialists to witness unity's organizational strength and to its capacity to the waste of time and effort resulting from sand damage, manage its own water supply system. when relatively simple measures incorporated in the design of wells could practically eliminate the problem. It The Handpump is a fundamental principle of well design that a well screen and filter pack are provided to prevent sand Chapter 4 deals with the different factors which can incursion, except in consolidated rock where there is no affect handpump performance, and the remainder of this danger of formation movement and the designer can document is devoted to analysis of handpumps which consider leaving the hole uncased for the rock section. have been tested by the Project. If proper attention has Even in this type of well, the soil overlaying the rock been given to the establishment of appropriate comm- section must be cased and grouted, to prevent abrasive unity management; if the capacity and limitations of the particles from cascading down the hole and being drawn aquifer have been recognized; if the well has been into the pumping elements. soundly designed and constructed; and if the main- The right combination of pack material and slot size tenance capabilities of the community and the support can ensure that formation sand cannot move into the facilities available have been critically assessed and well to cause blockage or pump damage. In a low-cost matched to the level of skill required to maintain a comnmunity water supply project, there is rarely any need chosen handpump, then conditions are right for a for individual designs for each well; knowing the aquifer successful community water supply project. type, a safe design can be chosen. Planners, consul- Selection of the most appropriate pump for specific tants and contractors involved in community water site conditions involves a detailed appraisal of those supply programs in developing countries must recognize conditions and of the attributes of the different pumps on that proper design requires screens and filter packs in offer. Chapter 4 has the details. unconsolidated and semi-consolidated formations. Adequate supervision is needed during well construc- Finance tion, to ensure that installation is carried out correctly. Malawi's Livulezi project (Box 3.3) provides a good In the years leading up to the International Drinking example of the impact that good well design can-have on Water Supply and Sanitation Decade (IDWSSD), rural pump reliability. Before the project began, seals were water supply was a badly neglected sector. Low invest- replaced on average every six months on each of over ment, poor achievements and a weak political lobby led 4,000 handpumps. The project brought improved control to the sorry coverage statistics quoted at the beginning of well quality, as a result of which 85 of the 106 pumps of Chapter 1. needed no seal replacement after an average operating That situation is changing. In the course of the period of two years. IDWSSD, governments have increasingly recognized the potential benefits of community water supply invest- Long-term performance of drilled wells can also be ments, and the pace at which improvements can be improved considerably by proper well development. accomplished if appropriate low-cost solutions are Extensive sand pumping before the well is brought into adopted. Donors too have committed themselves to the commission, boosts the water flow into the well, avoids integrated approach, and have taken initiatives to coor- clogging later by removing fine material from around the dinate their activities in support of programs based on screen, and reduces the amount of sand which might low-cost technologies. otherwise be working its way towards the pumping The mood is now right for accelerated progress, but elements. The Project has found that well development the needs are enormous. Continuing efforts are needed is often neglected or poorly carried out, partly because to bring down costs, and to ensure that health and there is a belief that for a handpump well it does not economic benefits are maximized. matter. A properly constructed well will outlast even the Well construction will normally be the biggest best handpump by many years. capital cost item in a handpump-based water supply program. At present, well costs can range from less than The only visible part of the completed well, apart from the US$200 for a 50m deep hand-drilled well in alluvial plains pump itself, is the surrounding apron. In simple design in South Asia to US$20,000 or more for a machine-drilled terms, the apron serves to protect the well from pollution well of the same depth in the harder formations in West caused by contaminated water flowing back into it and Africa. Geology has a big effect on drilling costs, but prevents muddy pools of standing water from forming even in very similar geological conditions, the Project around the pump. The pump apron also provides an has found that there can be a 5-10 fold difference in opportunity to promote improved health and hygiene. costs for the same kind of well in different regions. HANDPUMP PROJECT PLANNING AND IMPLEMENTATION 45 In India, a 50 meter well drilled by a local contractor purchasing power effectively. Removing import duties on using a locally-made down-the-hole-hammer drilling rig raw materials and other taxes for locally-manufactured will range in cost from about US$1,500 to US$2,000 - handpumps will not only stimulate national industry, but very similar to costs in the USA and other industrialized also encourage potential importers to cut profit margins nations. In Africa, it is rare to get a 50m well for less than in order to compete. Standardization policies should also $5,000 and not uncommon for the cost to exceed increase the competition for initial orders. $15,000. The Handpump Compendium includes indicative The difference comes from the organization of well prices for many of the handpumps presently available on drilling and the equipment used, and can be substantially the market. The range is quite wide, with a clear price influenced by unrealistic currency exchange rates. In advantage in favor of pumps manufactured in developing the past, donors have often supplied sophisticated countries. With a few notable exceptions, pumps suit- drilling rigs, theoretically capable of drilling perhaps a able for low-lift applications should be available for less well a day, but in practice achieving as little as two or than US$200 per unit, including rods and rising main. As three holes a month. Drilling equipment should be pumping lift increases, prices of both the pumping unit chosen so as to be operable and maintainable within the and the rods and rising main rise, and so does the range existing capacity of the public sector or contracting of prices. So, for a pumping lift of 30 meters, the total industry, and should be standardized for any one cost of pump, rods and rising main can be as low as country. US$500, or as high as US$2,500. The scale of water supply development needed Handpump prices can have an impact on the capital (70% of Africa's rural population lack access to safe cost of projects, particularly when wells are shallow and water) demands lower costs. Otherwise, the cost of drilling/digging costs are low. However, the right choice providing sufficient wells with handpumps to give a level of handpump is even more critical in relation to of service which people value will be prohibitive. There is recurrent costs. Though handpump maintenance no evident reason why costs of well drilling in Africa costs vary greatly in different parts of the world, and few should not come down close to those in Asia. Achieve- individual countries have examples of each type of ment of reasonable well costs should be a high priority of system, the extensive data collected during the Project governments and donors alike. Both must recognize the clearly demonstrate the general rule that the greater the need to build up a national drilling capability, preferably involvement in maintenance activities of agencies out- in the private sector, and create a competitive climate by side the community, the higher the maintenance cost. encouraging local contractors to purchase appropriate Malawi's Livulezi project offers a good example (Box equipment and submit bids for drilling projects. 3.3). With 200 pumps maintained by village caretakers Part of the solution lies in using the right drilling and repairs carried out by two trained government main- equipment. Box 3.5 shows a few of the many different tenance workers, the average annual cost of maintaining drilling technologies in use in various parts of the world. each pump during 1984 and 1985 amounted to US$24, or Too often though, the choice available is dictated by US$0.10 for each of the 250 users per pump. donor preference and the market in the industrial Significantly, two-thirds of the costs relate to overheads countries, where there is little demand for the shallow, and transport costs for the government maintenance small-diameter holes in remote places which charac- activities. Once pumps have been installed which are terize handpump programs in developing countries. VLOM in both the above and below-ground compo- Selection is usually a compromise involving cost, speed, nents, the indications are that the resulting savings maneuvrability and technical sophistication. when full village-level maintenance is introduced will The growth of indigenous rig manufacturing bring annual maintenance costs in Malawi down to 5 or 6 industries in India and Brazil is leading to innovative cents per user. designs specifically for rural water supplies. There are At the other end of the scale, a centralized main- positive signs too that, partly because of Project initia- tenance example from another African country shows tives, major rig manufacturers from industrial countries the prohibitively high transport costs (US$135 per year) have recognized the large market for drilling rigs and administrative charges (US$30) involved in main- designed specifically for rural water supply work. taining each handpump. Added to a direct labor cost of Evaluation of drilling methods and management will US$19 and spare parts cost of US$9, these result in a be an important component of the Project's second total maintenance cost of US$193 per pump per year. phase, with the aim of focussing the same concentrated Even with the comparatively large user groups (about attention on this major cost element as has been 400) commonly served by one handpump in that region, devoted to handpump development in the first phase. centralized maintenance is costing almost 50 cents per Well costs tend to dominate community water supply user per year. economics, at least in terms of capital investments. That For logistical and financial reasons, centralized does not mean that handpump costs should be neglec- maintenance is not a viable economic option for most ted. The large competitive market now opening up, and countries. To replace a piston cupseal costing as little the increasing scope for in-country manufacture of as US$2, a truck with 3-4 people has to be sent out from proven handpump designs, should lead to a progressive the base camp, travelling perhaps 100km to the pump. lowering of pump prices. This trend will be given added The whole operation can end up costing US$200-300. impetus if developing countries and donors use their 46 The economic argument in favor of community-man- save money, and make community management aged maintenance is decisive and is reinforced even easier to achieve. further by the improved reliability of handpumps serviced at the village level. Dependable pumps are valued by The Community users, who will be willing and able to pay the compa- ratively low costs involved in maintaining them. What is * Community participation should include involvement needed is a suitable mechanism within the community for of a water committee in the selection of service collecting and administering maintenance funds. level, well location and technology choice, as well as Attempts to initiate simple accounting practices for project construction. the upkeep of CWS systems have not always met with success. If agricultural credit banks, post offices or * Financial and technical commitments must be shown farmers' cooperatives already exist in the vicinity, water to be within the community's capabilities, and any committee members can be trained to take responsibility operational links needed between the local manage- for a maintenance fund, under the guidance of such an ment and external agencies must be established organization. However, many communities are out of before the scheme is implemented. Private sector reach of convenient banking facilities, and must rely on mechanics have been shown to be an effective a cash box kept by a designated community member. bridge between the central authority and the Despite the risks, the Burkina Faso example in Box community. 3.1 shows how such a system can work successfully, while also stimulating private mechanics to spread their * Government extension workers should be respon- influence over a wider region, because of the mutual sible for training village pump attendants and benefits. Maintenance costs are extremely low - only management in operation and maintenance needs US$0.05 per user per year, compared with an estimated and cost recovery procedures, and this should be US$0.65 per user per year replacement costs for the backed up by refresher courses and project moni- alternative rope and bucket systems - yet the mech- toring and evaluation. anics find the earnings attractive, and provide prompt service when there is a breakdown. * Though full community management is the ideal, Other examples exist of workable community transitional stages in which community members financing of handpump systems, but there is a need for take on limited responsibilities, to reduce the load on more data. During the second phase, the Project will the central agency, can have a significant impact on further analyse different maintenance arrangements and costs and reliability. The important criterion is that offer guidance for governments and donors. institutional, technical and financial resources match the needs of the selected system. Summary of planning Guidelines The ultimate objective should be full community res- Analysis of the six key elements in community water ponsibility for management of point source supplies. supply projects using handpumps points to a series of guidelines, which, with the supporting evidence outlined The Aquifer in this report, may lead CWS planners towards estab- lishing the conditions for optimum performance and reli- * National and regional data collection on groundwater ability in a handpump-based community water system: resources provides valuable information for hand- pump project planning and design. Existing and new The Maintenance System wells should be monitored, to build up as complete a picture as possible of aquifer geometry, water * The trend towards increasing community manage- quality and potential yields. Governments should ment of handpump systems is soundly based, exploit the effectiveness of available computers, as keeping down costs and improving reliability. a means of establishing a groundwater data base Contracting of nearby area mechanics (or which can be continually updated. privatization of the service) will prove to be the optimum solution in many cases. * Knowledge of seasonal groundwater level fluctu- ations and carefully executed pumping tests are * Every element of system design should be directed especially important in low-yielding aquifers, to towards simplifying the upkeep of the completed ensure that well depth is adequate to provide suffi- scheme and ensuring that skills, tools and materials cient dry season yields. Selection of the right will be available when needed. Spare parts and tools handpump and cylinder setting depend on accurate should be distributed to each community as part of assessment of maximum drawdown (and thus maxi- project execution. mum pumping lift). Drawdowns of tens of meters have been recorded in handpumped wells located in * Scheduled servicing, involving periodic replacement low-yielding aquifers. of wearing parts, should be evaluated in the project planning stage, as it is likely to reduce breakdowns, * Regulation of aquifer development through legis- HANDPUMP PROJECT PLANNING AND IMPLEMENTATION 47 lation is the best way to prevent handpump wells down as a result, but further reductions are from being undermined by later developments necessary if needs are to be met. involving motorized pumps. Legislation should also be considered as a means of protecting groundwater * Drilling is the most significant capital cost item in a resources from pollution due to surface activities. handpump project, and drilling costs remain much too high in several parts of the world, and parti- The Well cularly in Africa. New strategies are needed, to encourage private sector initiatives, and to develop * Sand and silt ingress into pumping elements is a drilling techniques appropriate for CWS programs. major cause of handpump breakdown. Properly This will be a key element of phase 2 of the Project. designed screens and filter packs have been shown to reduce damage to seals and valves dramatically, Encouragement of handpump manufacture in devel- and should be seen as an essential element in drilled oping countries can stimulate competition and bring well design for unconsolidated or semi-consolidated down costs, in addition to the benefits for operation formations. Proper well development will also and maintenance. improve the long-term performance of wells and pumps. * The economic argument in favor of community- managed maintenance is decisive, and the resulting * Though hydrogeological conditions influence the improvement in system reliability increases the choice of well location, community preferences community's willingness to pay for the upkeep. should be taken into account when possible sites are selected. * Simple financing and administrative arrangements for community management of handpump-based * Full advantage should be taken of the amenity value CWS systems are proving successful in several of the well apron, to promote improved health and countries, and further analysis of these arrange- hygiene. Clothes washing, bathing and small-plot ments will be included in the second phase of the irrigation can be encouraged by good apron design. Project. * The right drilling equipment and management can substantially reduce the well costs - commonly the Handpump-based community water supplies have to be largest cost element in the whole CWS system. seen as a package of elements, each important in its own right, but with the balance of the elements also vital The Handpump to long-term success. Inadequacies in pump design or installation will lead to unsatisfactory performance, even * The above guidelines are intended to establish the on properly constructed wells, just as good pumps optimum conditions for operation and maintenance cannot be expected to function reliably on badly of the handpump. Final selection involves detailed constructed wells. Even the best pumps need repairs consideration of the attributes of individual pumps in sooner or later, so appropriate organization of comm- the particular conditions for which they are being unity management of maintenance is essential; ineffec- chosen. That is the subject of Chapters 4 and 5. tive and expensive centralized or regional maintenance does not provide the needed service. The central Finance authority does have a role to play in the setting and monitoring of standards, training of community care- * The International Drinking Water Supply and Sani- takers and area mechanics, and in the organization of tation Decade has seen a marked switch in favor of adequate outlets for spare parts (preferably within a CWS strategies based on community management bicycle ride of the village) when VLOM pumps are being of low-cost technologies. Unit costs are coming used. 48 Handpump failure rates in India dropped from about 70% Centuries in Europe and the United States. The Industrial in the mid-i 970s to about 20% less than a decade later. Revolution brought mass production techniques for cast This transformation came after an intensive program by iron and meant that thousands of manufacturers were Indian central and state governments and UNICEF to able to turn out handpumps to meet the huge demand for develop appropriate pumps and maintenance systems. It convenient water supplies at that time. It has been is a good demonstration of the influence that pump estimated that some 42 million handpumps were made in selection and system design can have on handpump the USA, mostly in the period up to 1920, when electric performance. Recent and continuing handpump improve- pumps began to replace them.2 ments mean that much higher success rates are If the basic design of the reciprocating handpump achievable if enough emphasis is placed on the critical has not changed much in the 20th Century, its use issues: choice of suitable pumps; maintenance certainly has. European village pumps were huge arrangements; well construction; spares availability; and structures, serving as much a monumental as a training. Progress made during the last few years has functional role, while the big market was for smaller provided answers to many of the earlier problems, backyard pumps used for 10-30 minutes a day by though anumber remain to besolved. individual families or farmers. Today in the developing Working conditions for handpumps in developing countries, a single pump may have to supply up to 500 countries are severe. Many hours a day of pumping, villagers and be in continuous operation for 10 or more rough handling, corrosive groundwater, and inadequate hours a day. maintenance are among the challenges that face Though the potential market for such pumps is vast, manufacturers attempting to offer reliable products. little development work went into designing handpumps Problems highlighted in India and elsewhere in the specifically for rural water supply applications in late 1970s, in preparation for the Water Decade, pro- developing countries until quite recently. Manufacturers vided the impetus for the Project. Since 1981, field trials continued to supply the old backyard pumps, and rarely and laboratory tests have amassed unique comparative received any feedback about how their pumps were evidence on the performance of handpumps under widely performing under the totally different operating differing conditions, enabling the Project to offer conditions. informed advice on how to choose pumps which will give During the 1970s, other types of positive displace- the best performance. For manufacturers, the message ment pumps, commonly used for industrial applications is that the key elements of future designs should be: (the diaphragm pump and the progressing cavity pump), robustness of fixed components; easily-replaced, low- were adapted for rural water supply use and installed in a cost and readily available wearing parts; and corrosion- number of developing countries. At the same time, resistant materials. UNICEF sponsored a great deal of research and develop- ment work in India, culminating in the first production History of Handpumps models of the India Mark 11 handpump in 1978. The first Indian national standard for this pump appeared in 1979. The history of handpumps goes back a long way; Box 4.1 overleaf describes the operating principles McJunkinl reports the use of positive displacement and the merits and shortcomings of the five principal reciprocating pumps in Ancient Rome as early as 275 ____________ BC. One of the best documented early examples of a 1. F.E. McJunkin, Hand Pumps, The International Reference wooden pump using metal flap valves, from Saxony, was Centre for Community Water Supply, The Hague, The Nether- recorded by Agricola in the 16th Century. lands, 1977. But most of the reciprocating handpumps in common 2. Bernard Ewbanks, The Story of the Pump and Its Relatives, use in developing countries today have their origins in 1971, Salem, Oregon, USA (private printing of 400 copies), page designs developed during the late 19th and early 20th 171. HANDPUMP TECHNOLOGY 49 Box 4.1 Handpump Types and Operating Principles Of the 42 pumps featured in the Hand- familiesorsmaligroups. There is no need for priming, which is pump Compendium (i.e. all pumps which All the moving parts of a suction also an advantage over suction pumps. have been subjected to laboratory pump are located above ground, and They differ from suction and deepwell and/or field tests during the Project), 38 only the suction pipe extends down into pumps in that the operator's effort is are reciprocating pumps; 2 (Mono and the well. On the upstroke (illustrated) applied directly to the plunger, without Moyno) are progressing cavity pumps; water above the plunger is forced out the mechanical advantage achieved and 2 (Vergnet and Abi-ASM) are diaph- through the discharge spout and more is through a lever or flywheel. This ragm pumps, both using the same down- drawn into the cylinder through the open elimination of the mechanical advantage hole components. The laboratory and check valve. On the downstroke, the restricts application of direct action field trial results do not indicate major check valve closes, the plunger valve pumps to the depth from which an indivi- performance differences related to mode opens and water passes through the dual can physically lift the column of of operation. The most useful classifi- plungertobeliftedinthenextcycle. water. On-the other hand, the mecha- cation for pump evaluation and selection The operating limit is set by baro- nical simplicity of the pumps and the is the depth from which particular pumps metric pressure (equivalent at sea level can drawwater-i.e. the pumping lift. to a 10.4 meter head of water) and the effectiveness of the seals, which make LOW LIFT the practical limit only about two-thirds of full barometric pressure. This 7 meter Suction Pumps limit on pumping lift is the biggest drawback of suction pumps. With water Suction pumps draw water from shallow tables falling below that level in many depths by creating a partial vacuum in parts of the world where such pumps the suction pipe. Depending as they do have been installed, the pumps are _ Pump rod on atmospheric pressure to drive water becoming inoperable and must be . Rising main up to the surface, their use is restricted replaced with deepwell pumps. to regions with water tables no more than Another serious disadvantage of Cylinder 7 meters below the surface, but in those suction pumps is that they must be --Piston areas they have been very popular for primed by pouring water into the space Foot valve reasons of both economy and conve- above the plunger each time that Strainer nience. There are more suction pumps in pumping recommences. Use of contami- use in the world than any other type; nated water for priming is an obvious over one million are known to be installed health hazard, which is difficult to avoid. in Bangladesh and there are several In their major application as family million in China, mainly serving individual pumps, suction pumps do not need to be potential for low-cost, lightweight const- as sturdy as handpumps used by larger ruction, makes them well equipped to communities, and the low lifts also meet VLOM objectives. subject components to less stress and Use of large diameter lightweight reduced wear. When typical suction pumprods can help to balance the effort pump models have been subjected to needed on the upstroke and downstroke, community use, they have generally and reduce the stresses on the rods and PistonX I shown rapid wear and poor durability. In linkages. This element of direct action Suction check valve the Project trials, heavy use caused fre- pump design is being studied as part of quent problems with the Lucky, Jetmatic the Project, and is discussed in the and New No 6 pumps. Only the SYB-1 00 section on Pumprods in the main text. in China proved reasonably robust in Though some direct action pumps community use. are still in the development stage, there -Rising main has been extensive experience in a Direct Action Pumps number of countries over the past 16 years to justify the Project's optimism Foot valve is Suitable for pumping lifts of up to about that such pumps can have widespread . opstional for 12 meters, direct action handpumps are application for community water sup- reciprocating pumps which can continue plies, offering considerable advantages to operate when the water table has over suction pumps for low-lift appli- fallen below the reach of suction pumps. cations. 50 INTERMEDIATE AND HIGH LIFT turned into a pumping action through Progressing Cavity Pumps alternate stretching and relaxing of the Deepwell Reciprocating elastic membrane (diaphragm), which is A rotary motion provides the lifting Pumps filled with water in a closed system. energy in progressing cavity pumps. An Expansion of the diaphragm inside the accurately machined helical rotor turns In deepwell pumps, the cylinder is rigid cylinder closes the suction valve in a fixed rubber stator and progres- immersed below the water level. They and opens the delivery valve, driving sively pushes the water upwards conti- are suitable for lifts down to 45 meters or water to the surface through a flexible nuously. The meshing surfaces provide more, depending on the effort that users hose rising main. When the diaphragm their own moving seal. A gearbox contracts, water is drawn in through the transmits the operator's rotation in the suction valve, as in a conventional crr Rod hanger reciprocating pump on the upstroke.The Chain Fulcrum connecting principle of the pump is attractive, link because it allows the use of flexible tube for the pilot hose and rising main and is therefore easy to install or remove without the need for special tools or equipment. Diaphragm life is compara- tively short, and replacement may cost Rising main as much as US$200 in the field, beyond Pump rod many villagers' capacity to pay. Piston Pump rod Cylinder Rising main R Valve Cylinder Rotor Stator Foot valve c Operating pedal Strainer are willing to apply for progressively less ,,,_ _ water as depth increases. The sub- merged cylinder eliminates the need for , | f f, ~~~~~vertical plane into a horizontal plane priming, but means that repairs or main- rvro,tica plane into a hodriota planIe tenance involve removal of components | J version with the handle rotating in a from down the well. vI w t Deepwell reciprocating pumps exist l Ll \ horizontal plane is also available). One in a number of forms, with the operating advantage of rotary pumps is that they mechanism available as a lever, a fly- Pilot pipe Pilot piston are simply converted to motorized or | . . L ~~~animapoe.Othotehndte wheel or a pedal, and a variety of ways Pilot cylinder al power. On the other hand, the of converting the operator's action into a rods and rotor assembly need special ofcconvertingmotionof the orratng. Wintoh Discharge pipe lifting equipment when installed in or reciprocating motion ofteplunger. With j-.i removed from deep wells. economy and ease of maintenance as 1 11 11 1 important selection criteria, a consi- C-IockI derable amount of Project time has been T fiveControl check valve devoted to monitoring the performance T fv co a of differentdeepwellpumpdesigns. Dischargecheck valve pump types tested during the l lill lill ~~Handpumps Project. Pumps with Diaphragm Pumps Pump Elsi oe other operating principles are being body Elastichose used for community water supplies, The illustration shows the Vergnet foot- Cylinder though the Project has not tested pump, but the same downhole compo- them. Among the options available nents are used in the Abi-ASM, which Foot valve are air or water Jet pumps and has a conventional lever handle. In each Strainer pulsating (inertia) pumps. case, the operator's applied force is So.rce Etablissements Pierre Mengin, Monrargis, Franc HANDPUMP TECHNOLOGY 51 pump types: suction pumps; deepwell reciprocating remove conventional downhole components), and 45m pumps; direct action piston pumps; diaphragm pumps; (considerable effort is needed below that depth to and progressing cavity pumps. These categories cover produce acceptable discharge rates). the majority of pumps presently on the market, and all of A critical factor to be taken into account is the those tested by the Project. Other interesting designs do drawdown of the water table which will be caused by exist, such as air or water jet pumps, and pulsating pumping of water from the well (in addition to any (inertia) pumps, but models based on these operating seasonal drawdown and general lowering of the water principles have not been tested by the Project. table caused by nearby motorized pumps). For high- As UNICEF's involvement in village water supply and yielding wells in permeable formations, the discharge sanitation programs built up during the 1970s, the from a handpump will cause minimal drawdown. However, agency undertook monitoring exercises in a number of where the maximum yield of the well is in the same order countries and, for the first time, a picture began to as the pump discharge rate, excessive drawdowns can emerge of just how many handpumps were out of order. result (drawdowns in excess of 20m have been India, which had been investing heavily in rural water recorded). Figure 4.2A in Box 4.2 shows the variation in supplies based on handpumps from the beginning of the drawdown over a few hours pumping in some typical low- 1970s was found to be suffering badly from breakdowns. yield wells in Southern Ghana. Average static water level In 1975, UNICEF reported that at any given time 70 to in this region is 10 to 12 meters below ground, but 80% of the handpumps were out of order. pumping can lower it significantly, as the graph shows. Other countries too were finding it impossible to keep In low-permeability rocks, such as the basement pumps in operation. A 1977 US Peace Corps survey rocks of Africa, high seasonal fluctuations combined found that only 40% of the handpumps in Sierra Leone with high drawdown often bring pumping water levels were working. In 1982, the International Development down to the level of the cylinder intake. When that Research Centre (Canada) reported that in Sri Lanka happens, air pumping may occur, possibly accompanied only 60% of recently installed handpumps were still by sand movement, seal damage and heavy shock loads functioning. Few countries seemed able to keep more on the pump. than 25-50% of their pumps in service at any one time. Pumping tests will give an indication of likely well yields and drawdown for different pumping rates. Factors Affecting Handpump Selection should then be restricted to pumps capable of Performance delivering enough water at the increased pumping lift, but it may also be prudent to eliminate high discharge pumps The Project field trials have produced considerable new if these would draw the water down excessively. evidence about the way that handpumps function and the factors influencing their performance and reliability. 2. Daily output Chapter 3 dealt with the elements of the water supply Daily output is a convenient way to express the demand system which have to be considered if the pump is to from an individual pump, as it combines domestic water have a chance of achieving optimum reliability. In consumption calculated on a per capita basis with other selecting the handpump itself, the designer can take supplies for small-plot irrigation, animal watering, etc. advantage of Project experiences by comparing the Chapters 2 and 3 have dealt with the choice of service ratings given to pumps in the Pump Selection Guide, levels and the compromise which must be made on deep Chapter 5 of this document. First it will be useful to wells between the economic number of users per pump examine the effects of various operating conditions on and the time and effort needed to raise large quantities of the breakdown rates and downtime of different types of water from great depth. pumps. In comparing handpumps for a specific lift and daily output, the important parameter will be the pump's actual Operating Conditions discharge rate at the given head (in other words the number of pumping hours needed to achieve the required 1. Pumping lift daily output). Project observations clearly show that, One of the key design criteria for any handpump is the whenever there is a choice, handpump users will favor depth from which water must be lifted to the surface. In the pump which fills their containers more quickly, even the case of suction pumps, there is a physical limit fixed if, within limits, it is heavier to operate than alternatives. by the height at which the water column can no longer be Provided therefore that a high discharge pump will not supported by atmospheric pressure. In practice that cause air pumping as a result of excessive drawdown, means that, at sea level, suction pumps should not be and/or sand-flow problems in the well, its choice is the used if the pumping level will be more than 7 meters onemostlikelytobeacceptedbyusers. below the surface, and at higher altitudes the limit is less (down to 4.5m at 3,500 meters, the elevation of much of Maintenance System the Andean plateau of South America). Lift limits for other pump types are less precise, though the Project The practical and economic arguments in favor of has found it convenient to categorize pumps according community management of handpump-based water to their performance at maximum depths of 12m (the systems were given in Chapter 3. This principle will have approximate limit for present designs of direct action an important influence on handpump selection, and it is pumps), 25m (beyond which lifting gear is necessary to imperative that project planners (and manufacturers) 52 Box 4.2 Drawdown in Low-Yield Wells: Examples from West Africa Basement rocks, which occur across large areas of upland Africa and Asia, are essentially impermeable Figure 4.2A Drawdown and Recovery crystalline rocks and will transmit water only when of Five Handpumped Wells in fractured or weathered. Deep weathering is common Southern Ghana in tropical wet areas, such as the forest belts of o west, central and east Africa, and these rocks, though their permeability is low, provide an adequate aquifer for widespread development of handpump- 5 based rural water supplies. In dry zones, like the Sahel, often only minimal weathering has occurred ^l and groundwater is limited to fractures in the crystalline rock. Low permeabilities can cause problems due to 15- very high drawdown of the water level in the well \ ®fPumpingrae during continuous pumping. Yields from wells are 2 --- X ( Pumpinutes generally low; analysis of data from 110 positive 50 boreholes drilled in the Liptako area of Niger shows \l that 14% yielded less than 1 cu m/h and another 25- I 1 29% produced 1-2 cu m/h. This is by no means \ D 12 unusual in the Sahel region, and is reasonably 5.5 indicative of the situation in other dry zones. 30 Caution is needed when determining maximum 0 1 2 3 4 pumping lift and selecting handpumps for low-yiel- Pumping and recovery time (hours) ding wells, because excessive drawdown can lead to sand pumping and damage to both the well and the such as permeability are often more important than pump. Figure 4.2A plots the drawdown and recovery the pumping rate in determining drawdown, as of five wells with different permeabilities in Southern evidenced by Curve 1, where the well with the Ghana. Each well was pumped continuously for three highest pumping rate has the least drawdown. hours, at the rates shown, then allowed to recover. To prevent air pumping and well and pump In each case, the static water level was 10-15 damage, the well depth and cylinder setting must be meters below the surface when pumping started. The deep enough to cater for anticipated drawdown, and figure shows that drawdown can easily exceed 10 in low-yielding wells the pump chosen should have a meters where permeabilities are low, even when design discharge reasonably matched with the well pumping rates are low (curves 3, 4 and 5). Factors recharge rate. recognize the elements of handpump design which make mechanic, C - Centralized maintenance. a pump suitable for village-level maintenance. While it is These classifications are chosen to represent certainly true that handpump reliability suffers different levels of skills, tools and equipment available dramatically when the community depends on fallible for pump maintenance, as these are the ruling criteria in external support, many projects also fail because village handpump selection. Pump performance may also be utilities take on maintenance commitments that are influenced by the way that the maintenance is managed beyond their capabilities. (by the community or a central agency), as discussed in Much of the Project field study work has been Chapter 3, but the choice of the pump itself will not be concerned with identifying the causes of breakdown or affected by the management system adopted but by the poor performance of different handpump types in maintenance structure available. different operating conditions. In the Handpump Typically, a pump which needs a mechanic to remove Compendium, readers will find details of the frequency and replace handle bearings, plunger seals, or other with which each field trial pump needed repair or wearing parts will not be classified as suitable for maintenance interventions, and the pump components maintenance under a Level A system, and any pump which caused breakdown or poor performance to occur. which requires heavy lifting tackle to remove the cylinder From this information, and knowledge of the skills and and rising main, and motorized transport to carry equipment needed to carry out repairs, the Project has essential spare parts, demands a Level C system. rated pumps according to their suitability for satisfactory Pump reliability (availability) depends on both the maintenance under each of the three typical frequency of breakdowns and the length of time for which maintenance structures - i.e. A - Village-level, B - Area- the pump is out of service each time it needs HANDPUMP TECHNOLOGY 53 Box 4.3 Corrosion of Downhole Components and The Effects on Water Quality High failure rates of galvanized rods and rising mains concentrations shown in Figure 4.32, and meant that in the corrosive groundwaters found particularly in the pumps were no longer rejected by users because the West African field trials were surprising and of unacceptable water quality. worrying. Concern has prompted study of the factors Selection of corrosion resistant materials is affecting corrosion, and the effects on the taste of therefore very important if groundwater is aggres- water drawn from affected wells. The issue of taste is important. Overnight build- Figure 4.3B Changes in Iron Concen- up of iron concentrations in wells with corroding rods trations in Well Water due to Substi- or rising mains can be very high. Figure 4.3A shows tution of Corrosion-Resistant Pumps the result of pumping tests on wells in southern Ghana where the galvanized pumprods of the Moyno 60 Moyno pumps - ~~~~~~~~(galvanized pump Figure 4.3A Variations in Iron Concent- rods and ration during Pumping 50 rising mains) V _ergnet pumps 60 mg/4I (corrosion- 24 resistant downhole 20 -o30 components) E 16 - n20 Wells 1. 2, and 3 had been used very little handp s i eWells 1, 2, and 3 are used very little.a with wonumps. geerll bee won ob esta gl h ey pms orsostems ithl cause. pMeasure 10 C 8 8 o 1 i~~~~~~~~~~~-~~~~~--- 23 fell away rapidly aspmin rate Uortnate Well reference number Hoee,maurmnsi_n well just threeuday sive. But, how do we recognize aggressive ground- afterumin thiesmevaed (hours thwntalio atper? Unfrtunatefuly theervedi neor tstimlanswe. t Pumped water quantity (mlo) this question. The first obvious step is to inspect any existing installations in the project area for evidence of corrosion. handpump were being attacked by corrosive Analytical evidence can also help if there are groundwater. Natural groundwater iron content existing wells in the area. If dug or drilled wells equip- measured in wells equipped with corrosion-resistant ped with non-corrosion resistant handpumps show handpumps in the West African field trial areas has higher iron concentrations than wells without such generally been found to be less than 1 mg/I. The very pumps, corrosion is the most likely cause. Measure- high initial iron concentrations in the illustrated wells ments of electrical conductivity and pH are impo- fell away rapidly as pumping progressed, reaching rtant, to indicate whether water from different wells stable low levels within two hours in most cases. originates from the same aquifer. It is also important However, measurements in one well just three days that iron analyses are performed in-situ or the water after the test revealed that the initial iron samples are carefully preserved before testing. concentration was as high as before the test, Assessment of the corrosivity of water is a proving that accumulation of corrosion products from complex matter, involving a number of inter-related the pump was the major cause of high iron content. water quality indicators. The pH is a valuable Lightly used pumps lead to greater accumulation indicator of aggressivity and thus corrosion of corrosion products, unless they are made from potential. As a rough guide, water with a pH value corrosion resistant materials. Experience shows that below 6 is likely to be highly aggressive; while above the problem intensifies as the daily pumping rate pH 7 there should be little or no corrosion. It must be drops below about 2-3 cu mid. stressed however that these are only guideline Changing some Moyno pumps for Vergnet figures, as other factors, such as conductivity, C02, pumps, which have plastic hoses and stainless steel chloride and sulfate content, as well as the presence cylinders, produced the dramatic drop in iron of bacteria, also influence corrosivity. 54 attention. Village-level maintenance is preferred because of its potential for a rapid response, and the fact that VLOM handpumps will usually be repaired very quickly, as no special tools or equipment are needed. The presence of monitoring engineers and regular visits from Project staff inevitably means that hand- pumps in the field trials received prompt attention when ,, ,f6 poor performance occurred, and that all the expertise -r ,*, i," and equipment normally associated only with Level C L- 'f maintenance was on hand. It is not possible therefore to ' k-r. use field trial results as a measure of response times for A the different levels of maintenance. On the other hand, e .,,. data collected during the Project from many countries, - ' and documented case studies elsewhere, provide ample N.. evidence that centralized maintenance means long delays when breakdown occurs, and that full village-level maintenance is very much quicker than any system depending on outside intervention. In comparison with response time, the actual time taken to carry out repairs to the pump has much less inf- luence on total downtime. It is however a useful indicator of the complexity of pump maintenance, and therefore the scopexforpvillagers to carryioutthenwork. Mobile maintenance teams (Level C) may be the only way to service some of the heavier handpump types, or those installed In West African trials on pumps set at depths of on deep wells. Most such systems are expensive and unreliable, about 35 meters, for example, servicing of the cylinder and pump selection should seek to achieve simpler maintenance an a Volanta pump was achieved in less than 30 minutes, whereverpossible. whereas a similar operation with the India Mark II and Moyno pumps took more than five times as long, even when all the necessary equipment and staff were on hand. Recent experiments with the Afridev prototypes in East Africa have shown that it is possible for two people to change the plunger and footvalve in about half an hour. Corrosion Resistance Of the 150 breakdowns experienced in the first two years It is important to stress that galvanized steel is not by a total of 275 India Mark II and Moyno handpumps immune to corrosion. Field tests have shown that galva- equipped with galvanized rods and rising mains in the nizing defers the onset of corrosion damage to rods and southern Ghana field trial, more than 60% were related to rising mains, but does not stop it, or slow its pace once corrosion - an extreme, but by no means isolated case. the coating has gone. Typically, the use of pipe Box 4.3 shows the effects of corrosion on various pump wrenches to connect galvanized rods and rising mains is components in the Ghana field trials, and demonstrates enough to damage the zinc coating and initiate the dramatic changes in drinking water quality when corrosion. When handpumps which do not use corrosion- pumps with galvanized rods and rising mains (Moyno) resistant components are also non-VLOM pumps, were replaced with pumps using plastic hoses and stain- corrosion has a major impact on maintenance costs less steel cylinders (Vergnet). because of the need for outside repair teams to replace The incidence and extent of corrosion damage damaged components. depends mainly on three factors - pump component Mild steel, even when galvanized, should be avoided materials, groundwater quality, and (often overlooked) if water is thought to be aggressive. Many manufacturers the pumping regime. The last point is especially impor- who supply galvanized rods as a standard also offer tant in connection with a secondary effect of corrosion stainless steel at extra cost, so that pumps need not - its impact on the quality and taste of the water. necessarily be rejected until this option has been Corrosion of steel rods and rising main leads to a buildup explored. of total iron content and results in an unpleasant bitter Of present reciprocating handpump designs, the taste and to discoloring of food cooked in the water and best corrosion resistance is provided by those using staining of laundry. plastic rising mains, stainless steel, brass or plastic cyl- Such pumps may well be rejected, or used only inders, and stainless steel, wooden, or fiberglass rods. rarely, and it follows that use of corrosion-resistant Ratings in the Pump Selection Guide take into below ground components should be considered even if account standard pump designs. Manufacturers should the groundwater is only mildly aggressive, as overnight be contacted directly for information about availability of accumulation of corrosion products may put off potential special corrosion-resistant options, though where the users. Project is aware that a particular pump can be supplied HANDPUMP TECHNOLOGY 55 - _ needed, and saves on foreign exchange. One of the requirements for a pump to be described as VLOM, is its suitability for local manufacture, though this does not exclude importation of some parts (e.g. bearings). Producing the entire pump, rather than just A_ frequently used spare parts, in the country where it will be used, has the further advantage that parts which may in F|F* gv ' . F w 1 * need replacement less frequently, such as the handle or f i f 1 ' [r ' '~ ( X 1^1' spiston, will be more readily available when needed. Economic viability is an important factor in the decision about whether to undertake in-country manufacture of handpumps. In-country manufacture has been the accepted practice in Asia for many years. Pumps such as the India Mark II, Bangladesh New No. 6, and Korat (Thailand) If pumps can be manufactured in the developing country, have been installed in such numbers that the marketing availability of spare parts is greatly improved. The photograph of spare parts has become a commercially attractive shows a pumphead made in Cote d'lvoire, which is to be joined to a downhole assembly made in France. activity at the retail level, greatly facilitating prompt repair of pumps. In Africa, a number of pumps are now being successfully and economically manufactured. with resistant components, this is noted in the A few examples illustrate the possibilities: a Catholic Handpump Compendium. Mission workshop in Burkina Faso is currently producing about 35 Volanta pumps a month; about 10,000 pumps Abrasion Resistance have been manufactured in Cote d'lvoire, including some for export; Mali produces the standard Mark II pump from The best way to combat abrasion damage to pumping India; new manufacturers in Ghana and Niger are making elements is to prevent sand and silt from entering the handpump prototypes; several hundred Maldev (Malawi) well by incorporating carefully designed screens and pumps have been manufactured in Malawi; Kenyan filter packs (see Chapter 3). Unfortunately, experience companies have started production of the Afridev; and shows that many handpumps are installed on old wells or discussions are under way for a joint-venture company in wells which have not been adequately protected against Tanzania to produce a direct action pump. A cautionary sand ingress. note should however be added. It is vital to avoid the No handpump is totally immune to the accelerated creation of a monopoly in one country, except possibly wear caused by sand-laden water, but some design during a brief initial phase. Otherwise, the result may be features will reduce the damage. Cup seals and valves higher prices and poor manufacturing quality. are most at risk, with leather cup seals particularly prone Manufacturers from the industrialized countries are to rapid wear. Sand becoming embedded in the seals will starting to seek joint ventures and licensing also abrade the cylinder wall. Best resistance to arrangements, as a way to retain their involvement in the abrasion is provided by rubber or plastic seals and handpump market and improve distribution and valves (nitrile rubber seals have performed particularly maintenance support. well in lab and field trials and their use may lead to substantially better handpump performance in sandy wells, which would be a major step forward in handpump technology) and stainless steel cylinders, or by designs incorporating seal-less plungers (or no plungers, as in progressing cavity pumps). Sand can damage pumps in other ways too. In West Africa, for instance, accumulation of sand deposits, mostly entering from above ground, has led to -- breakdown of some Vergnet pumps, by partially filling the diaphragm and so restricting its movement that it bursts i or becomes ineffective. Manufacturers are being urged to make abrasion resistance an important criterion in future designs, but _ ..- - Project field observations show that this problem is most -- effectively tackled first by proper well design and -- development (see Chapter 3). Manufacture India Mark 11 handpumps presently serve more than 200 million Readily avaie speople. The standard design requires both skill and effort when Readily available spare parts are a prerequisite for downhole components need maintenance. Modified designs reliable pump maintenance. In-country manufacture aimed at simplifying maintenance are being tested In the improves the chances of parts being on hand when Handpumps Project. 56 Countries vary greatly in their manufacturing capabilities, and a pump requiring, for example, skilled welding, iron casting or press work may be suitable for manufacture in some countries but not others. This has been taken into account in the Pump Selection Guide by rating each pump under three separate headings related to the industrial base of the country in which it is to be used. Manufacturing capability is one aspect to be considered when deciding whether to opt for local manu- facture of handpumps. Quality control is another - the Project has good evidence that inspection procedures and quality testing are essential if premature break- - downs are to be avoided with current pump designs. An . - important VLOM objective is to design pumps in such a >.x way that the need for extensive and stringent quality control is reduced to a level which can be achieved in Flywheel operation of handpumps has its critics, but the Volanta most developing countries. pump, seen here operating in West Africa, has proved popular Early prototype models of Malawi's Maldev pump throughout that region. suffered rapid ball-bearing failure. By the time that full production commenced, improved jigs and fixtures and tight quality control in pumphead manufacture had Handpump Design and Development doubled bearing life. However, this quality control is not easy to sustain, and field trial data shows that field-fitted A glance at the Pump Selection Tables and worked bearings have a shorter life than those fitted in the examples in Chapters 5 and 6 will show how restricted a factory. The Afridev pump was designed to overcome choice is available to system designers seeking to follow these problems, by using plastic bearings which require the Project advice on pump selection. Past emphasis on less precision in pumphead manufacture and are easy to weight and strength as the criteria for pump reliability has replace in the field (see Boxes 4.5 and 4.6). meant a preponderance of handpump models which are Government policies on import licenses, duties and not suitable for village-level, or even area-mechanic main- taxation can also have an impact on the decision about tenance. local manufacture of handpumps. The ex-factory prices The problem is particularly severe when pumping lift of many pumps made in Africa include a sizeable cost increases, as one of the chief impediments to local component for duties on imported raw materials used in maintenance of handpumps is the difficulty of removing their manufacture, and sometimes also a sales tax. On pistons, cylinders and foot valves from deep wells. the other hand, imported pumps are usually exempt from Wherever the rising main has to be withdrawn in order to all import duty and tax, which gives foreign gain access to the cylinder for repair, the need for manufacturers an unfair advantage. Though duty and tax special lifting tackle will almost inevitably mean that a concessions to local handpump manufacturers may be centralized maintenance system will have to be adopted. difficult to administer, changes in national legislation are After many years experience with some 500,000 India needed to permit local manufacturers to compete on Mark 11 pumps, Indian manufacturers have devised a level terms with importers. system for removing long lengths of galvanized iron rising main without lifting tackle. However, the method User Reaction still calls for skill and effort on the part of the mechanics and helpers involved. Though pumps cannot be rated under this heading on a A simple gantry and pulley permanently installed on global basis, because much depends on local culture, the pump platform has been used to ease maintenance in religion, etc., a number of aspects of pump design can at least one handpump program and may offer another affect a community's reaction to a particular handpump. kind of solution. In extreme cases, villagers, especially women, may be Most presently available pumps have essential unwilling to use pumps which require postures or components which require special skills or processes to movements which they regard as strenuous or produce them, or are protected by proprietary restric- undignified. Footpumps, flywheel-operated pumps and tions, so that local manufacture is inhibited. Finally, of even direct action pumps have been reported as being the few pumps which do offer simple maintenance and unacceptable in isolated cases, though the Project has readily available spare parts, not all offer resistance to been unable to corroborate such reports. corrosive or sand-laden water. If there is any doubt, pictures, films or demon- Considerable progress has been made in handpump stration models of proposed pumps should be used design and development since the start of the Project, during the pump selection process, so that villagers are and research has been promoted into a number of prom- aware in advance of the operating procedure for each ising and novel ideas. The remainder of this Chapter pump under consideration. Public education in the use of contains specific recommendations for handpump handpumps sometimes helps to overcome initial resis- manufacturers and industrial researchers about the tance to a newly-introduced pump. direction in which future applied research and technology HANDPUMP TECHNOLOGY 57 Box 4.4 Effects of Handle Design and Cylinder Size on Pumprod Stresses PUMP A PUMP B Cylinder diameter - 50 mm Cyiinder diameter - 64.5 mm X ~~ ~ ~ - _ 65.5 kZ-f -______98.11ig-f E 3 i pE S 5 it- li1 kg f _. 491k- 16.4 kg-f ___-- 81.7 kg-f 49.1 kg-f~~~~~~~~~~~~~~~~~~~8.7k- Field trial observations have shown that users of through the same distance produces Ihe same dis- lever-action handpumps tend to move the handle end charge. However, the pumps are subject to quite by the same amount irrespective of the total stroke different forces, as the diagrams show. The different length available. This constant travel distance (usu- lifting forces mean that for a given rod diameter, the ally in the range of 300 to 400mm) is maintained stresses in the pumprods of Pump A would be 40% as long as the operating force is within acceptable less than those in Pump B. limits. This finding has considerable significance for Alternatively, the stress could be kept constant, handpump designers. in which case a rod of 40% less cross-sectional The diagrams show two possible designs for area, or 23% smaller diameter, could be used for the handpumps to raise water from a depth of 25 meters. 50mm diameter pump. Such a rod would be lighter On the left (Pump A), the pump has a handle ratio and cheaper and induce less inertia. (mechanical advantage) of 3:1 and a cylinder There are also substantial differences in the diameter of 50mm. On the right (Pump B), the handle forces acting on the bearings. The hanger bearings ratio is 5:1 and the cylinder diameter 64.5mm. will be subject to the same forces as the rods, with The 25 meter head of water on the 50mm dia- Pump A's lifting 40% less load than Pump B's, while meter cylinder results in a required lifting force of the fulcrum bearing carries the total downward force 49.1 kg-f in addition to the weight of pumprods and of handle effort and pumprod force and is 33% less plunger. For the 64.5mm cylinder, the required lifting for Pump A. force is 81.7 kg-f, again plus pumprods and plunger. Use of a 50mm diameter cylinder compared with After taking account of the different handle ratios, one of 64.5mm diameter has therefore considerably the force to be applied by the user (assuming that reduced all the forces acting on the key wearing the pumprod weight is balanced by an appropriately parts of the pump, providing the opportunity to use counterbalanced handle) is 16.4 kg-f in each case. smaller and lighter materials without affecting either For the same handle movement of 300mm, Pump the pump performance or the operating action. A will produce a plunger movement of 100mm and a This is an important conclusion, which has discharge of 0.2 liters from the 50mm cylinder, while guided Project research towards adoption of the Pump B's 60mm plunger movement will result in the smallest cylinder size needed to cope with the range same discharge from the 64.5mm cylinder. of lifts for which a particular pump is designed - a To the user therefore Pumps A and B are iden- reversal of the commonly held view that larger tical: the same operating force moving the handle cylinders offer advantages. development should be directed, to provide the most initiated by the Project has focused on improvements to reliable pumps for a range of pumping applications. There the performance and serviceability of such pumps. The is great scope for improvements to existing pumps as field trials showed that reciprocating pumps cover a well as evolution of new designs. wider range of discharge and head ratings than The recommendations are based on principles which alternative designs, and their inherent simplicity makes are now firmly established as the most effective way to them more amenable to local manufacture and village- achieve sustainable and replicable large-scale rural level maintenance. Many of the issues discussed in this watersupplies. section of the report will therefore relate primarily to recip- rocating pumps. Pump Types This should not discourage development of hand- pumps based on other pumping concepts. The Project The handpump market is dominated by reciprocating has recognized great merits in, for instance, the Vergnet pumps, and much of the research and development work diaphragm pump, which avoids the use of pumprods, 58 uses flexible plastic pipes and has its plunger readily accessible at ground level. The Mono and Moyno prog- ressing cavity pumps also have particular strengths, in X that they eliminate the need for plungers and seals and are able to pump water with a significant sand loading. Further development of these and other designs (oscil- lating water column, water or air jet, etc.) may have considerable potential and manufacturers and resear- chers are encouraged to study the concepts guiding development work on reciprocating pumps, outlined in the following pages, and adapt them to their own fields of interest. The Project will be interested to hear of any promising new designs, and is willing to offer comments and suggestions in amplification of findings summarized _-__-_ in this Report. Of the 42 pumps in the Handpump Compendium, 32 This boy has jumped in the air to bring his full weight down on the are lever operated, 5 are direct action (Malawi Mark V, pump handle. Better designs are available, but the photograph demonstrates that users will be prepared to apply considerable Ethiopia BP50, Nira AF85, Blair, Tara), 3 are flywheel effort,if the water supply is convenient and reliable. operated (Climax, Volanta, Duba Tropic 7), 2 are foot- pumps (Kangaroo, Vergnet), and 2 are rotary (Mono, Moyno). than 20 meters. There would seems to be no reason to Direct action pumps (see Box . 4.1) are discourage further development of foot-powered pumps, comparatively inexpensive and simple to manufacture though it is prudent to check local cultural traditions and to maintain, and the Project is advocating wide- before installing pumps of this type. spread use of this type of pump for shallow pumping lifts A simple development of lever action which has (certainly to 12 meters, and possibly to 15 meters). much to recommend it is the use of a T-bar. A big Flywheel operation of handpumps is a contro- advantage is that it encourages proper use of the versial topic. Advocates point to the substantial reduc- handle, because users stand behind the handle and tion in shock loading on the pump system from the move it in a vertical plane. This contrasts with the progressive acceleration and deceleration of the characteristic operation of a straight lever, where users flywheel in comparison with the rapid stress reversals tend to stand alongside and exert lateral forces on the which can be induced by lever-action pumping. A pumphead and bearings. T-bars make two-person properly counterweighted flywheel can also build up operation easy and provide counterweight for the pump- considerable rotation speed - particularly when oper- rods at the optimum position. ated by two people - and so achieve comparatively high A counterbalanced handle is a useful way of discharges, even when the pumping lift is high. It is this optimizing the forces needed on the upstroke and high delivery at great depth which has made the Tropic 7 downstroke. Taking account of the lever mechanical popular in Niger, where its discharge from 45 meters is advantage, a heavier handle, or one with counterweights threetimes that of the India Mark II. attached near the end, will decrease the force which the Critics say that the rapidly spinning heavy wheel user must apply on the downstroke, adding an equal with its protruding handles is a hazard to children and old increment to the upstroke. people, though the Project has found little evidence of As a minimum, counterweights should balance the injuries from this source, which seem to occur only when pull of the pumprods and plunger, which would otherwise flywheel pumps are newly introduced into a region. return the handle unassisted (the India Mark II relies on Another criticism is that flywheel-operated pumps are this gravity return, as it uses a chain and quadrant link more difficult and more costly to make than lever- between handle and pumprods). In some cases, extra operated pumps, because they are heavy and need counterweight, forcing a positive upstroke, can make correspondingly strong (and therefore expensive) pump- pumping very much easier at high lifts. heads and bearing assemblies. Average cost of the four flywheel pumps tested is more than double that of lever Discharge Rate versus Pumping Effort action pumps for the same pumping lifts. There is a large potential use for flywheel pumps in An important observation from all the field trials is that regions where water levels are deep and high discharge when users are able to compare different pumps under is needed (pastoral applications in the Sahel are an the same operating conditions, they almost invariably example), but the lower cost and reduced complexity of favor the ones with the highest discharge rate, even lever operated pumps make them more appropriate for though the force required may be relatively high (it must most regions. not, of course, be excessive). In extreme cases, the Footpumps have sometimes been criticised on the community may reject pumps which produce low grounds of supposed cultural objections to the posture discharges irrespective of the effort applied. adopted by a female operator. The Project sought evi- A useful general principle for future designs, dence for this assertion, but none has come to light. In therefore, is that handpumps for community water supply fact, the foot pumping action of the Vergnet is praised by should give high yields, even if that means compara- some users, particularly where the pumping lift is less tively high handle forces (as a rough guide, the Project HANDPUMP TECHNOLOGY 59 Box 4.5 Development of Plastic Bearings for Lever Action Handpumps For the light use normally associated with the original factory. European and US backyard pumps, mild steel pins in The Project selected bearing development as a cast iron journals were an adequate bearing arrange- key research issue and has sponsored and carried ment at the fulcrum and rod hanger. Heavy pump use out considerable laboratory and field work to produce in developing countries, however, results in very new designs. The target was to achieve a reasonable rapid pin wear quickly followed by wear of the handle and predictable bearing life (1-2 years) from both and pumphead. factory-fitted and replacement bearings. As with all The India Mark II design in the mid 1970s intro- the Project development work, overall objectives duced two standard replaceable ball races at the included simplicity and low cost in manufacture of fulcrum (the Mark II has a chain and quadrant bearings and pumpheads, as well as ease of replace- arrangement as the rod hanger). The ball bearings ment, to allow village-level maintenance. resulted in a greatly extended life (typically 2-4 Tests started in 1982 on dry bearings using a years) and, with some difficulty, could be replaced range of engineering plastics running on different when worn, avoiding damage to the pumphead. Other metal counter surfaces. Low wear rates, acceptable manufacturers followed suit, and many handpumps life and easy replacement of plastic bushes were now have standard, off-the-shelf ball bearings at the readily achieved, but a big problem was that the fulcrum and rod hanger. metal (mostly stainless steel) counter surface wore Though the improvement was substantial, ball as well and eventually had to be replaced. bearings have several disadvantages for handpump In early 1985, collaboration with plastics applications. Designed for high-speed uni-directional specialists from Du Pont in Geneva, Switzerland, led rotation, they are less suited to the slow rocking to a design concept involving one polyacetal bush action of a handpump lever; bearing housings have running on a second polyamide bush. The combin- to be very precisely machined, calling for good ation exhibited barely detectable wear in laboratory quality control in manufacture; field replacement and field trials and has now been developed into a needs a special tool and some skill, and poor fitting design in which the two bushes snap together to form leads to bearing damage; "sealed for life" bearings one self-contained unit that can be fitted into the are not water or dust proof, while conventional pump without special tools. The injection molding bearings need regular lubrication. Also, failure to process has to be closely controlled, but plastic recognize or respond to the symptoms of bearing bearing production has recently begun in Kenya. wear (lateral handle movement is the first sign) can This is an early attempt to produce plastic still lead to pumphead damage. In the Sudan field bearing designs specifically for handpump appli- trials, irreparable damage was done to Mark II pump- cations, and the results are encouraging. Mass heads because of failure to replace worn bearings. produced, the bearings are very cheap and therefore In the Maldev design (Box 4.6), an attempt was relatively easy to hold in stock; simplicity of made to ease field replacement by increasing toler- replacement makes scheduled servicing viable; and ances, but reduced precision led to shorter bearing the Kenyan experience suggests that local life, and there was an impression, to be verified as manufacture is a feasible option for countries monitoring proceeds, that wear is more rapid on the wishing to follow this route. Field trials will continue in replacement bearings than on those fitted in the Kenya and elsewhere. recommends that a handle force of 20 kg-f should only uncomfortably heavy to use. So, pump users are willing be exceeded at very high pumping lifts). to apply quite high forces, but prefer limited movement. Only a few manufacturers allow alteration of the Pumping Actions handle mechanical advantage (in practice this can be accomplished by varying the handle length) as an option. The field trials have demonstrated that lever-action pump Yet the right combination of mechanical advantage and users tend to use roughly the same handle movement cylinder size can significantly reduce the forces and irrespective of the total available stroke. The movement therefore the stresses on pumprods and bearings. As is usually about 300-400mm and represents a Box 4.4 demonstrates, a 3:1 handle ratio and 50mm comfortable operating action. Different users operate in cylinder diameter results in the same discharge per different parts of the available handle arc, and handle 300mm handle stroke for the same operator effort as a design should therefore allow for comfortable use of a 5:1 handle ratio and 64.5mm cylinder diameter, yet the 300-400mm movement at various positions to suit the pumprod and bearing loads in the former case are 40% stature of different users. and 33% lower respectively. The handle movement is more or less independent of These observations tend to counter the commonly the handle operating force, until the pump becomes held view that the largest practical cylinder size should 60 be used for any particular pumping lift. This policy in the The principal wearing parts in the pumphead are the past has led many manufacturers to offer a range of cylin- bearings, and these have proved to be the weak link in der sizes and multiplied the needs for stocks of spare many pump designs. The Project has promoted a great parts. Other manufacturers make only one cylinder size, deal of research and development into bearing design but specify their pumps for only a limited range of lifts. specifically for handpump applications (see Box 4.5 The Project staff believe that, as far as practical, a overleaf), and has concluded that engineering plastics single cylinder diameter should be adopted and that this may offer a viable solution. Bearing assemblies have should be the smallest size needed to cope with the been designed that are easy to fit, have a fairly long life, range of pumping heads met. Discharge, and the can cope with some dimensional variation in pumphead corresponding handle force required at different pumping manufacture (compared with the tight tolerances needed lifts, can then be controlled by mechanical advantage - in ball races), and can be mass produced at low cost. i.e. the highest discharge is achieved by the longest Some promising designs are under test in the field trials stroke, using the minimum handle mechanical advantage and early results are very encouraging. needed to keep the force within acceptable limits. For bearings, plungers, footvalves, rod connectors, For example, a 50mm diameter long-stroke cylinder seals, and possibly other components too, it is certain can be used for the full range of lifts up to 50 meters, as that properly designed plastic components (as opposed follows: to plastic copies of metal components) will have a big impact on future handpump designs. With direct action (1:1 mechanical advantage), the The Afridev design (Box 4.6) already incorporates handle force can be kept below 20 kg-f for lifts up to engineering plastics in bearings and many below ground about 12 meters by using a large diameter low-mass components. Research and development work for this pumprod to distribute force and discharge between application is being undertaken by plastics specialists the upstroke and downstroke. from industrialized countries alongside the young but enthusiastic engineering plastics industry in East Africa. * With a suitably counterbalanced lever handle with a 3:1 mechanical advantage, the same 50mm cylinder can be used at lifts of 12 to 30 meters. Pumprods * Lengthening the handle to give a 4.5:1 mechanical Pumprod breakage has been a common cause of failure advantage makes the pump suitable for lifts in the during the field trials, most frequently occurring at the 30-50 meter range. threads where the rod is linked to the handle in the pumphead. In most lever action pumps, the rod hanger The Afridev pump range uses this concept (see Box link is a fixed one, through which the lever force may be 4.6). In contrast, the standard India Mark II employs a transmitted through a bearing to the rods to give a 63.5mm cylinder and a handle with a fixed mechanical "positive downstroke" during rapid pumping. The India advantage of 8:1 (some manufacturers of this pump offer Mark II is an important exception, in which the rod hanger variations for lifts outside the normal specified range). is a chain and quadrant. In this "gravity return" arrangement, the weight of pumprods and plunger Role of Plastics effects the downstroke, and movement of the handle does not push the rod down. Until very recently, handpump designs had benefited Opinions differ as to the merits of gravity return. little from modern materials technology. While market Some say that it reduces pumprod fatigue by avoiding forces have prompted big investments in the develop- buckling on the downstroke, while others argue that it ment of mass production items like the plastic clips for induces greater stresses because of "snatch" in the the trim panels of a motor car, the large market for hand- gravity return arrangement. To help resolve this issue, pump components has not attracted the same attention. the Project is conducting a laboratory-based study, The Project, along with other organizations such as which will compare pumprod stresses for gravity return IDRC in Canada and the British ODA, has promoted and and positive downstroke systems. sponsored testing and development of handpump compo- Conventionally, most pumprods have been made of nents made from different plastics, and sees scope for galvanized cold-drawn mild steel rod. Galvanized pipes numerous beneficial applications. and wooden rods have also been used successfully, The potential use of commodity plastics, like proving beneficial for lowering the starting torque of polyvinyl chloride (PVC), high-density polyethylene windmills, for example. The Duba Tropic handpumps use (HDPE), and others, for rising mains is discussed later. wooden pumprods, and the few tested in the field trials Engineering plastics, designed for specific purposes, have operated satisfactorily, though the test period is are being used more and more in industrial applications, still quite short. to replace metals, and should be well suited for a similar Galvanized mild steel rods usually perform satis- role in handpump designs. Their attractions include factorily in non-aggressive groundwaters, but rapid corrosion resistance, toughness, and guaranteed corrosion where water is aggressive has led to uniformity of complex parts through controlled injection widespread use of stainless steel rods in such situ- molding and long-lasting dies. If demand is high, costs ations. Rods normally have threaded connections with can be very low, as raw materials are comparatively sockets and this feature, often but not necessarily inexpensive. coupled with corrosion, is the prime cause of rod failure. HANDPUMP TECHNOLOGY 61 Box 4.6 Case Study of Handpump Development in East Africa The name Afridev has been given to a family of hand- * designed to minimize forces, al owing the use of pumps, still being developed under the sponsorship of lighter components which can incorporate a larger the Project by a group of mechanical engineers design safety factor. This can give improved working for governments and donors in several East fatigue life for relatively highly stressed compo- African countries. Design concepts have evolved from nents, such as pumprods and rising mains. experience during the Project field trials, and experi- mental components are being blended with proven * low cost, so that user communities can generally designs in an attempt to address each of the design afford to purchase the pump (perhaps with credit) issues discussed in this chapter. and can always afford to maintain it. Target The main objective is to produce a family of figures are: US$400 for a complete pump set at designs which will be available in the public domain and 25m depth, with full recurrent costs of less than which can be adapted for manufacture in many devel- US$30 per year. oping countries. The principles guiding research and development In effect, the Afridev is a continuation of develop- are that pumps should be: ment work which began in Malawi early in 1981 and resulted in the first production models of the Maldev in * modular in design, so that the same cylinder, mid-1982. The original Maldev pumphead uses ball rising mains and standard wearing parts can be races the same size as the India Mark II (two in the used for direct action pumps to 15 meters and handle fulcrum and one in the rod hanger) and was deepwell pumps to 50m. designed for use with uPVC rising mains and extractable plastic plungers and footvalves. * as simple as possible to install and maintain with Problems were experienced from the start of minimal tools, skills and effort, including an extrac- Maldev production, mostly connected with the tight table piston and footvalve. manufacturing tolerances demanded by the use of ball races. Life of the bearings was unacceptably short * relatively simple to manufacture in medium-sized and field replacement unduly difficult. Though tigh- well-managed workshops in East Africa, requiring tened quality controls overcame the initial problems to straightforward production engineering and min- some extent, the requirement for simple field fitting imal quality control. Designs make maximum use meant that larger tolerances had to be allowed, and of stock size materials, to minimize the amount of failures were still too frequent. This particular issue is machining required. explained in more detail in Box 4.5, and it led to the conclusion that further development should include * designed so that scheduled servicing should alternatives to ball races in the pumphead assembly. result in the virtual elimination of breakdowns and The new prototype, renamed the Afridev and that such servicing involves only routine and including a fulcrum and rod hanger assembly with engi- simple replacement of easily accessible low-cost neering plastic bushes in place of the ball races, was wearing parts, such as bearings, seals and manufactured and installed in Malawi in late 1982. A valves. year's trial was enough to confirm the merits of the plastic bearing system, and Afridev development * suitable for use in aggressive groundwaters accelerated, with Kenya becoming the center of through the use of corrosion resistant materials activities. below ground; and capable of resisting sand The first machined prototypes of plastic downhole abrasion through proven seal and cylinder wall components were produced for field testing in Kwale combinations and intake configurations. District, on the Kenyan coast, late in 1983. Further Rolled threads and box and pin joints go some way hooked stainless steel rods, which makes removal and towards resolving this problem, but, especially for village- replacement quick and easy. The Afridev system (Box level maintenance, the use of threaded connections has 4.6) is testing prototype hooked connectors designed to to be questioned. It makes installation and removal eliminate lateral or vertical play and using a plastic guide inherently complex and there is a risk of damage through to align the rods and centralize the link in the rising main. cross-threading or over-tightening. Also, rods with An important development, linked with increasing threaded connections cannot readily be cut to length in use of direct action handpumps, is the use of high the field. displacement, low mass pump rods. Lightweight rods The Volanta has an innovative arrangement of with relatively large diameters can be formed from hollow 62 development work and field experiences led to second- mechanical advantage lever is offered, and for stage, injection-molded plungers, footvalves and rod applications involving lifts from 30 to 50 meters, the connectors, which were distributed for field testing mechanical advantage is raised to 4.5:1. early in 1985. At the start of the Afridev development, Meanwhile, an informal handpump design meeting conventional pumprods with threaded connections held in Kenya, towards the end of 1984, had set design were used. Problems with cut threads are well known, objectives for the Afridev. The fifteen participants of and these are only partly overcome by using rolled ten nationalities included representatives from 5 East threads (see Pumprod discussion in main text). African countries. They stressed the need for users to During 1985, the Project started experimenting with be able to obtain and pay for spare parts and to repair pumprods joined by a system of hooks and eyes, the pump themselves. The emphasis was to be on which allow the rods to be joined quickly and easily regular replacement of low-cost wearing parts rather without the need for any tools. The hooks and eyes than longer periods between more difficult and costly form hinges, and a plastic component was designed to repairs. A general target was set of one year between fasten over each hinge and prevent buckling of the spare parts replacement. joint under compressive loads. The same component A significant breakthrough came soon afterwards, serves as a pumprod centralizer, preventing contact with the finalizing of dry bearing designs suitable for of the rods with the rising main. In three field test mass production by injection molding. That completed sites, use of the prototype system has dramatically the pumphead design, which had altered considerably reduced the time needed to remove and replace since 1982, as new ways were found of simplifying downhole components; a large scale field trial is now maintenance. The first substantial production run of being implemented. the Afridev pumphead started towards the end of So far, uPVC rising mains have been used in 1985. about 50 prototype pumps, almost without failure for Tests on the downhole components led to further up to four years at pumping lifts up to 30 meters, and developments, and production designs emerged from most recently at lifts up to 50 meters. Research is a second design meeting in Kenya early in 1986, which continuing into simple methods of joining uPVC pipes, evaluated the full potential of engineering plastics in which will permit easy dismantling. Solvent cement handpump design. Plastic bearings are now being jointing, as currently used, is not considered an molded in Kenya using long-run dies (also made in the adequate solution. country); dies for molding plungers and footvalves are Although the research and development program being designed in Switzerland ready for mass produc- is incomplete and the field trials are continuing, the tion of cylinders in Kenya. Afridev pump is achieving many of the targets set for In the discussion of Discharge Rate versus it. Replacement of all wearing parts (bearings, plunger Pumping Effort in the main text, reference is made seals, valve bobbins) can be undertaken from a 40 to the advantages of standard long-stroke, small- meter setting (say a 30 meter water level) in sub- diameter cylinders, to reduce forces, ease stantially less than one hour by minimally trained maintenance and simplify spares procurement. A villagers, using a simple spanner and fishing tool, and decision has been taken that, for all pumping lifts, the without removing a single nut from a bolt. Afridev will use a standard 50mm diameter cylinder. The pumphead is being manufactured by four The operator force needed to pump from different companies in Kenya and prices are on target. depths will be varied by offering different mechanical A Production Manual is under preparation for the advantages in the handle. For lifts up to 12 meters, a Afridev, which it is hoped will make it possible for other direct action handle will be recommended with high- countries to adapt design and production techniques displacement pumprods. From 12 to 30 meters, a 3:1 to suittheirown circumstances. tubes of materials such as PVC or aluminum, or by and lowers the load on the rods during that stroke. There surrounding a steel bar with a very low-density sub- are also advantages for installation and removal of stance like closed-cell foam, or simply by using a uniform downhole components, if the rods are easy to lift. low-density material of which wood is the most obvious. High-displacement low-mass rods are being By displacing a big proportion of the water column in manufactured from standard off-the-shelf PVC pipe the rising main, lightweight pumprods transfer a (though other materials can also be used), with the substantial part of the total effort required from the added advantages of economy and corrosion resi- upstroke to the downstroke. Reducing the effort on the stance. Tests of PVC tubes as pumprods on direct upstroke makes the pump significantly easier to use, action pumps such as the Ethiopia BP50, IDRC-UM, HANDPUMP TECHNOLOGY 63 Blair, and Tara prototype have given mixed results. (bearing in mind also that, if VLOM pumps with extrac- Breakages and excessive abrasion observed in some table downhole components are developed, rising main cases were probably caused by low quality of the diameterswill haveto be much largerthan 42mm). material, wrong connector designs, insufficient pipe wall Plastics are an obvious option and a number of thickness, and weaknesses introduced by careless pump designs are now using plastic rising mains, with solvent cement jointing. Rods made from high-quality varying degrees of success. Preliminary results seem to materials, well manufactured and epoxy cemented (e.g. indicate that smaller diameter (up to 50mm I.D.) high- the Blair and the Wavin prototype) have performed well. specification uPVC pipe may be sufficiently durable and The Tara development (Box 4.7) demonstrates that inelastic to serve as a rising main at high heads. The only care is needed in balancing the advantages of high water known success with larger diameter PVC is the Volanta, displacement with potential wear problems if the annular where the flywheel operation means a steady acce- space between pumprods and rising main is reduced so leration and deceleration of the rod-piston assembly. much that deformation or poor alignment can cause Rising mains are subjected to repeated stress reversals, contact between the two during pumping. and there are reservations about possible fatigue A direct action system imposes special needs on failures in plastic pipes. High longitudinal elasticity and the pumprod. In addition to the balancing of upstroke and creep are other problems, as lengthening of the rising downstroke forces, rods generally move at higher main in relation to the pump rods would impair pumping speeds than those in conventional lever pumps, and will performance and could reduce the available stroke to be subjected to higher compressive forces. The threat of such an extent that damage to the plunger or upper buckling may call for the use of rod guides, further cylinder would result. Finally, there is the "notch reducing the flow space between pumprod and rising sensitivity" of certain plastics, a measure of the main. There would be considerable benefit if the rod susceptibility to high stress concentrations and potential could be a single section, strong enough and flexible cracking if the uniform wall thickness is interrupted by enough to be bent over and laid out on the ground during threading or accidental scratching or impact. installation and removal, though flexibility is in conflict The most common plastic rising main in use at with the stiffness needed to prevent buckling. present is uPVC, which is used in the Kardia, Volanta, Connectors, on the other hand, usually presuppose tools SWN and Afridev deepwell pumps, as well as many and may also be vulnerable to uncoupling during shallow lift and some direct action pumps. Exceptions operation or fatigue failure. are the Nira AF85 direct action pump which uses high Finding the best direct action pumprod involves a density polyethylene (HDPE) rising main (and pumprods) compromise among a list of desirable characteristics: and the Pek direct action pump which uses a polypro- low mass, high volume, high stiffness, high tensile pylene/polyethylene mix. strength, low elasticity, and high abrasion resistance. PVC pipe suffers less creep than many other plas- tics, but is highly notch sensitive. It can also be quickly Rising Mains damaged by exposure to sunlight, unless additives are used to increase its resistance to ultraviolet light. HDPE Galvanized mild steel pipes have been the conventional is less notch sensitive and more resistant to UV attack, material for rising mains with reciprocating and prog- but has much higher creep than PVC. Polypropylene ressing cavity handpumps. As with pumprods, galva- (PP) pipe has creep properties between PVC and HDPE, nized rising main performs well if groundwater is non- and an HDPE/PP mixture is said to combine the reduced aggressive, but has a short life in corrosive water. This creep of PP and the high notch resistance of HDPE. problem is aggravated by the poor quality of rolled and Down to about 20 meters, there is enough expe- galvanized pipes made in many developing countries rience of successful use of high-quality plastic rising (rising mains are often ordered locally for use with impor- mains to regard them as an acceptable solution. For ted pumpheads, cylinders and pumprods), poor thread deeper wells, critical issues remain of how to support the cutting, and poor quality pipe connectors. The heavy rising main in the well, the type of jointing used, and weight of steel pipe is another disadvantage, especially creep. As a simple precaution, the Afridev has nylon where the rising main has to be removed for routine safety lines attached to its cylinder, in case the PVC maintenance of the cylinder. rising main slips or breaks - a potentially disastrous There is therefore a need to identify satisfactory breakdown, as "fishing" for the pipe in a deep well is alternatives to galvanized pipes for handpump rising extremely difficult, even for a skilled repair team. mains. Stainless steel has the advantage that it is Some designers maintain that long rising mains must corrosion resistant, but it is much more expensive. be supported at the bottom, others use compressed Recent quotations for large orders of 11/4 inch nominal rubber rings to grip the pipe from the top. Jointing is (42mm O.D.) stainless steel pipe for use with India Mark difficult. Threads cut directly into the pipe have led to 11 handpumps in West Africa amounted to about $10 per pipes breaking. If threading is used, wall thickness must meter FOB Europe. That is a competitive price for be inreased (e.g. by a bonded sleeve), so that in the stainless steel pipe, but would mean that 30 meters of threaded section the minimum thickness is more than the rising main would cost almost twice as much as the FOB standard pipe thickness, not less. cost of the pumphead, cylinder and 30m of pumprod. In general, threaded joints are not a good solution, Though stainless steel may turn out to be the only option because of the difficulty of making them and tightening for aggressive groundwaters, the Project and other them properly in field conditions and the nature of the concerned groups are actively seeking alternatives materials themselves. 64 Solvent or epoxy cement joints are an alternative Repairs by Part Type (used, for example, on the Volanta), but also have their problems, largely because of the need to follow strict 30- procedures and use fresh solvent cement. There is also 25% pumphead components the disadvantage that if the the rising main has to be 25- 75% below-ground components removed from the well, it must be cut then re-cemented O 20- with spare sockets when it is replaced. The Project is c sponsoring development and testing of new concepts for " 15- simple connection and disconnection of plastic rising ) 10 mains which avoid the need for tools or special materials. l As VLOM reciprocating pumps seem likely to have an 5 open top cylinder to allow extraction of rods, plunger and footvalve without removing the cylinder, rising main HD F RH P RM FV OT removal should be a rare event, needed only if repairs Pumphead Below ground have to be carried out to the cylinder itself or to the well. Glass-fiber reinforced plastics (GRP) may be Parr replaced another option for rising mains, though at present they HD = Handle RH = Rod hanger RM = Rising main PE = Pumping element OT = Other P = Faicrnum PR = Pumsp rod PS = Piston seal PV = Pool valve are manufactured primarily for the oil industry and are almost as expensive as stainless steel pipes. Pump seals were the most commonly replaced components in Concern about the rising main issue has prompted the Project field trials, representing 25% of all parts replaced. inclusion of a laboratory research and development Below ground components accounted for 75% of repairs carried program on this subject in the next phase of the Project out, the remaining 25% being pumphead components. (1 987 - 1991). The aim will be to determine whether large The Handpump Compendium compares repair frequency by diameter PVC tubes (at least as large as the cylinder part type for individual pumps and demonstrates how variations diameter) can be used as rising mains at lifts of 45 in seal types and materials can have a significant impact on the diameter) canbe used as riing mains atnumber of maintenance interventions needed. meters, and if so, what design features and operating conditions make it feasible. Laboratory tests will first evaluate how the stress/strain relationship in PVC rising Plunger seal replacement is the single most common mains is affected by changes in design and conditions of maintenance need on conventional handpumps, yet it is use. Based on these results, recommended systems for also usually the most difficult task. To change a pair of conventional "positive-downstroke" pumps and for seals worth US$2 each on the standard India Mark II, the gravity-return pumps like the India Mark II will be pumphead must be disconnected from the pedestal and endurance tested. removed; rising main and pump rods have to be lifted from the well in 3 meter lengths and disconnected. The Cylinders cylinder then has to be opened and the plunger dis- mantled before the leather seals can be removed and Deepwell reciprocating pump cylinders have changed replaced. The whole process must then be repeated in little in design for 50 years. Cylinders are still commonly reverse. A typical repair involves several trained people manufactured using brass walls and end caps, cast and may take several hours. In the process, there are brass plungers and footvalves and leather cup seals. numerous opportunities for damage to occur to unrelated Even the comparatively modern development of the India components. Galvanizing is sure to be damaged by Mark II is modelled on the much older cylinder design, wrenches coupling and uncoupling pipes and pumprods, and has a brass sleeve inside a cast-iron casing. Of the and any abrasive dirt entering the open cylinder will mean plastic materials in use, uPVC is the most common, with an early repeat of the seal replacement. glass-fiber reinforced plastic (GRP) also used. Village-level maintenance is only practical if wearing Stainless steel cylinders with highly polished parts can be replaced easily and quickly, with minimum inner surfaces used with rubber hydraulic seals give risk of damage to other pump components. A first require- good resistance to sand abrasion and long seal life. ment is that the plunger and footvalve, if needed, should Softer brass cylinders are less resistant to the effects be removable without removing the rising main. of abrasive particles in the pumped water. Scoring and The Volanta handpump is unique in that the cylinder wear of the cylinder wall occurs, particularly when leather is located in a taper at the bottom of the rising main and it bucket-type seals are used, which tend to trap sand can be relatively easily extracted through the rising particles. main. Whilst this has some advantages, such as allowing uPVC cylinders have been used particularly on inspection and cleaning of the entire cylinder assembly, direct action pumps. It has the advantage of being it also has the major disadvantage that it requires a large comparatively inexpensive and widely available. As a diameter rising main. In fact, the 50mm diameter Volanta relatively soft material, it can wear rapidly as a result of cylinder needs a rising main with a diameter across the sand abrasion, though seal material and design can have sockets of more than 1 00mm, which precludes its use in an important influence on wear rate. the economically attractive 100mm drilled wells. A modi- GRP cylinders are becoming more common and fied version of the Volanta suitable for use in 100mm the inner surface is sometimes coated to reduce friction. diameter wells is now being tested. The Project has no firm data yet on wear rates of GRP Open-top cylinders allow the plunger and footvalve cylinders. to be withdrawn through a rising main only slightly larger HANDPUMP TECHNOLOGY 65 in l.D. than the cylinder itself. Such cylinders have been In the search for an alternative material for piston in production for many years and their ease of main- seals, nitrile rubber has shown the most promise so far. tenance has long been recognized. Again the drawback More definitive tests are under way, but first results from is the need for a comparatively large diameter rising field trials in India indicate that nitrile cup seals are more main, and this problem is aggravated if a range of cylin- abrasion resistant than leather seals tested under the der sizes is offered. Use of a standard small-diameter same conditions. Nitrile rubber is sensitive to oxidation cylinder, as recommended for other reasons in Box 4.4, by ozone, weathering and sunlight, but otherwise is a has the advantage of allowing the use of standard-sized reasonably stable material, which is not attacked by oil rising main, also of relatively small diameter. or by micro-organisms. An important advantage of nitrile Considerable work has been carried out in recent rubber (and other elastomers) over leather is that its years on the hydraulic design of plungers and foot- physical characteristics are more uniform and valves. The designer has choices to make about the predictable, allowing detailed quality specifications to be valve type, with, for example, flap valves, plate valves drawn up. and poppet valves each offering different benefits. Ring seals first appeared in handpumps in research Among the issues still remaining to be resolved on sponsored by IDRC. Typically two split rings of a the subject of detailed valve design are: whether the polymeric material are compressed into grooves in the valve should be light or heavy; what the valve port area plunger and fill the space between it and the cylinder should be as a proportion of the cylinder cross-sectional wall. Polyethylene was tried, but tended to collect and area; and what the valve lift should be. These and other retain abrasive materials. PVC filled with copper oxide questions are the subject of research under way by the was more satisfactory, and ring seals are seen as Project, IDRC and others. suitable for low-lift pumping, especially for direct action pumps, where moderate leakage rates are tolerable. To Seals date, the Project is not aware of ring seals having been used at high heads. Easy seal replacement is an important factor affecting A promising new concept in handpump design is the pump serviceability and has become a prime objective of replacement of mechanical seals with labyrinth or diodic VLOM designs. At the same time, the Project is evalu- seals. In the latter case, the analogy is with a diode's ating a number of different seal designs, to determine characteristic of resisting flow (current) in one direction, which last longest in different circumstances, the aim while offering little resistance in the opposite direction. A being to reduce the frequency with which seals have to similar principle can be applied to the problem of be replaced. inhibiting leakage past a plunger. Worn or damaged seals allow pumped water to leak Instead of a mechanical seal filling the space back past the plunger and so lead to reduced pump between the plunger and the cylinder wall, the plunger performance and ultimately failure. Some leakage is toler- geometry is designed to induce turbulence around it as it able in handpump applications, so the watertightness of is moved upward. Turbulent flow impedes leakage, but the sealing mechanism is not critical. The important point involves little or no mechanical friction to cause wear on is that the seal should be able to withstand the recipro- the plunger. cating pumping action through millions of cycles without One method is to use a long plunger which fits into excessive deterioration in performance and without the cylinder with a very small annular gap. The long damaging the walls of the cylinder (for instance through restricted flow past the plunger when the plunger valve is abrasion caused by sand). closed on the upstroke generates enough pressure to The laboratory and field trials have contributed a operate the pump. The Blair and Volanta pumps have great deal of data about the behavior of most present cylinders which work on this principle. seal designs, and have also pointed the way to further A variation is to add a convoluted wall profile (also research, some of which is already showing promise. close fitting) to increase turbulence even further. The Leather cup seals have been used for many cen- designs are attractive in that they eliminate the rubbing turies and remain the commonest form of plunger seal in seal. The concept is especially applicable for direct today's handpumps. Leather types and shapes have action pumps which have high plunger speeds and evolved empirically over the years and, though there is generate correspondingly high pressures. some conflicting evidence about the optimum tanning Diodic seals have not yet been specifically process for handpump applications, Swedish lab tests developed for handpumps, but appear to have potential. and field trials in India favor stiffer leather tanned using They are "solid state" devices, with no moving parts, the chromium oxide, and little further progress is likely to be design of which allows virtually unimpeded flow in one made in improving the performance of leather cup seals. direction but high resistance in the other (a vortex is one Leather has a limited shelf life. It deteriorates rapidly example). when subjected to extremes of humidity in storage, or to cyclical wetting and drying during operation, or to Standardization abrasion. As the field trial results for the India Mark II, among others, make clear, seal life can vary greatly Two of the greatest difficulties that developing countries depending on water quality, and particularly the amount face in keeping their rural water supply systems in of sand in the water. In the laboratory tests, seal life has working order are a scarcity of skilled mechanics and a varied from as few as 1,500 cycles to more than 10 lack of readily available correct spare parts. The million. problem is exacerbated in the rural water supply sector 66 Box 4.7 Case Study of Handpump Development in Bangladesh Irrigation from pumped wells is increasingly inter- The footvalve is seated at the lower tapered end fering with suction handpumps in Bangladesh, by of the cylinder, and can be captured for removal by drawing down the water table below the barometric means of a bayonet grapple on the end of the piston. limit of about 7 meters during the dry season. It may Valves in the piston and footvalve assemblies are be assumed that planners will continue to give higher stamped from automobile tire inner tubes. priority to increased food production than to pro- Development of the Tara is still going on. Though tection of existing suction handpumps, currently the basic design concept is sound, several problems estimated to number more than one million. There is remain to be solved: therefore a need for a cheap, reliable non-suction pump to substitute for those pumps which will be 1. Abrasion between the pumprod and upper well made inoperative and to be used in future rural water casing is beginning to cause system failures. This supply programs. problem is caused by bends in both the PVC This prompted research and development work, pumprod and the casing resulting in contact during supported by the Project, to develop an appropriate operation. Even if perfectly straight pipe could be direct action handpump. Long-term engineering extruded, it is doubtful whether casing alignment objectives of the Tara pump development include the could be maintained after installation, because of establishment of a locally manufactured pump-and- differential soil pressures. Two possibilities for tubewell system which is functionally adequate, overcoming the problem are being investigated - acceptable to users, reliable, inexpensive, and increasing the annular space between the pumprod maintainable by the users with a minimum of external and casing; and providing rod guides of a sacrificial assistance. To meet these objectives, strategic material, such as nitrile rubber, spaced at suitable decisions were taken at the beginning: intervals. More annular space can be obtained with a a. Extensive use of finished or semi-finished slightly smaller pumprod diameter (40 x 34mm) and mass produced items, such as standard PVC pipe, slightly larger casing diameter (63 x 57mm), without steel pipe and standard fasteners for the majority of compromising either the sludger drilling technique or tubewell and pump components, the aim being to the tensile strength of the pumprod. However, reduce the complexity of manufacturing to a changing to a smaller diameter cylinder (50mm) minimum set of processes and to use mainly off-the- compensates for the smaller displacement of the shelf, locally-available items. 40mm diameter rod, and the operating charac- b. Ensuring that the tubewell module is teristics of the pump are marginally improved. compatible with the indigenous "sludger" drilling technique, which enables Bangladesh to construct 2. Footvalve location and seating are not yet many thousands of small-diameter tubewells each positive enough to guarantee trouble free operation, yearvery economically. especially if the assembly is removed frequently for c. Provision of adequate pumping capacity per inspection. A molded snap-fit design is under inves- cycle, while keeping the required pumping effort tigation. within a range which could be accomplished by all users, including children. 3. A variety of piston seal types is under d. Elimination of the need for hand tools to ser- investigation: diodic seals, including seal-less types vice the pumping elements (valves and seals), so as and ring seals; elastomer cupseals; and improved to maximize the potential for caretaker maintenance. leather cupseals. e. Protection of moving parts from damage due to abrasion or corrosion. Future research will also focus on ways of eliminating metal threaded pumprod connectors and replace- The Tara plunger, which has recently been fitted with ment of the present friction seals with seal-less a nitrile rubber cupseal, operates directly in the plungers. To date, primary emphasis in development 54.3mm PVC rising main, which in Bangladesh also of the Tara has been on minimizing costs, and each forms the well casing. The pumprod consists of prototype has been based on use of relatively simple 42.2mm OD PVC pipe, leaving only a small annular materials and processes. It has to be recognized gap inside the rising main. The pumprod is sealed that solving the remaining problems may well involve and solvent jointed to form a captive air chamber increases in production costs. (see main text for a discussion of low-mass high- The Bangladesh-made unit currently costs displacement pumprods). Steel pipe is used for the about US$100 for pump, rods and rising main for an discharge head and for the T-bar handle. 11 meter setting. HANDPUMP TECHNOLOGY 67 by the variety of skills needed to cope with all the diff- and the lower discharges then mean that queues erent pump types, often supplied by donor agencies. It lengthen. Keeping a balance between per capita cost can be much improved by standardizing on only one or a and service level (quantity per capita and queue time) limited number of pump types, depending on the physical becomes more and more difficult as depth increases. conditions. Training programs can then have a sharper The list of available pumps, particularly those suitable for focus, and the potential for in-country manufacture of village-level maintenance, gets progressively shorter as essential pump components is very much increased. the pumping lift stretches from 25 meters to 45 meters. Pumps divide conveniently into three groups, categorized by the maximum pumping lift: Even when planned pumping applications would involve more than one of the above categories, standard- Low lift pumps. For lifts of up to about 12 meters, ization on one pump type may still be practical. The high discharges are a must, as users generally favor a majority of intermediate lift pumps will function adequ- pump which fills their containers quickly, and there is a ately at lower lifts, and a compromise on design objec- variety of pumps on the market which can do so. If the lift tives may well result in overall economies when operation is less than 7 meters (after allowing for any seasonal and maintenance costs are taken into account. If the drawdown or lowering of the water table by adjacent range of lifts is very high, different pumping actions may motorized pumping), suction pumps can be considered, be needed, but this need not necessarily preclude use of though the risk of contamination through priming with standard downhole components. As Boxes 4.4 and 4.6 polluted water has to be taken into account. A cost show, a standard 50mm diameter cylinder with the same competitive alternative, also well suited to village-level component parts can be used with different handle ratios maintenance, is provided by direct action pumps. Light (mechanical advantage) to cover the full range of lifts and easy to install and maintain, direct action hand- from 0 to 50 meters. pumps also dispense with the pumphead bearings which Manufacturers too have an important part to play in form one of the more difficult wearing parts to replace. standardization of pump components. The Project is col- Even without the mechanical advantage provided by the laborating with a number of manufacturers in an attempt lever handle of a conventional handpump, direct action to establish standard sizes for cylinders, valves, pumps can be operated comfortably down to 12 meters, bearings, etc, so that common spare parts can become and may in future be suitable down to 15 meters. off-the-shelf items widely available in developing coun- tries (so far efforts have focused mainly on Africa). * Intermediate lift pumps. For lifts of up to about 25 The Project has prepared Draft Sample Bidding Docu- meters, there is a wide choice of pumps available, with ments for the procurement of handpumps, which may increasing numbers being modified to make them more assist governments and support agencies in ensuring suitable for village-level maintenance. Recipient govern- that the important pump characteristics are taken into ments should resist the temptation to accept "free" consideration when procuring pumps through inter- pumps through grants from donors, if this will mean prolif- national competitive bidding. erating the number of pump types or installing unsuitable ones, and so straining maintenance capabilities. The cost of the pump itself is only a small part of any rural Guidelines for VLOM Design water supply program, but the wrong selection can have a crucial impact on the total cost and the sustainability of Following five years of intensive study of handpump the system. Final choice will depend on evaluation of performance in laboratory and field conditions and based groundwater characteristics, the maintenance capabi- on information collected from rural water supply projects lities of the benefiting communities, in-country manufac- throughout the developing world, it is possible to set turing potential, and the number of people to be served clear objectives for designers and manufacturers of from each pump, but a key consideration for CWS plan- handpumps intended for community water supply use. ners should be to minimize the number of pump types for Combined with the recommendations for planning and which adequate and correct spares have to be stocked implementation of handpump-based programs developed and skilled mechanics trained. Intermediate lift pump in Chapter 3, these technology-related guidelines form a design has progressed considerably in recent years, package which it is believed can make a dramatic impact with the introduction of open-top cylinders offering on the reliability of future community water supplies. increased scope for village-level maintenance. Some Manufacturers, researchers, government agencies, VLOM designs are now available for this range of lifts. consultants and contractors are urged to adopt these guidelines, with the background evidence contained in High lift pumps. A large majority of the rural people the earlier part of this Chapter, as a strategy for their in need of improved water supplies live in areas where design and planning activities to the end of the century. the groundwater table is less than 25 meters below ground level, but appropriate pumps are also needed for 1. Ease of Maintenance the remainder, who live where there are deeper aquifers. Handpumps should be designed in such a way that Handpumps can be reliably used at lifts of 45 meters scheduled replacement of all wearing parts can be (and are used at much greater depths), but the discharge carried out by a village caretaker after a minimum of drops markedly with increasing depth and maintenance training and with only a few basic tools. There should be becomes more and more difficult. More expensive drilled no requirement for heavy lifting gear to remove pistons or wells call for more users per well, to spread the costs, foot valves and no need for any vehicle (other than 68 perhaps a bicycle, public bus, or transport animal) to The India Mark II is the standard deepwell pump adopted carry tools or pump components. by the Indian government for its rural water supply program, and the pump is fully specified by the Indian 2. Robustness Standards Institution. The resulting economies of scale Non-wearing parts should be robust and durable. Within mean low prices; quality control is facilitated; and spares reason, they should be able to resist abuse, vandalism, availability is enhanced. Another example comes from the attentions of animals, climatic conditions in deve- Tanzania, where the government has established a loping countries, and corrosive or sand-laden water. Bureau of Standards subcommittee for standardization of handpump dimensions. By standardizing sizes such 3. Local Manufacture as those of the pump baseplate, different pump types Availability of spare parts, and hence handpump can be readily interchanged. reliability, is substantially improved if pump components can be manufactured in the country of use. It is therefore 5. Costs desirable that pump components should be designed to VLOM pumps should be low in capital and recurrent be simple to manufacture from widely available materials. costs. Target costs are US$300-400 for a pump, Specific and sustained attention must also be paid to the complete with rods and rising main, to lift from 25 meters, quality of manufacturing, through adequate quality and operation and maintenance costs should be kept control in the place of manufacture and regular external below US$0.25 per capita per year. Low-lift pumps quality assurance by the purchaser. should cost appreciably less, so that, for the same per The move towards in-country manufacture can be capita cost, more frequent wells with handpumps can stimulated if developing countries ensure that import bring safe water nearer to people's houses, and dis- license arrangements and tax policies do not inhibit courage the use of alternative, polluted sources. investments by local industry. Joint ventures with estab- lished manufacturers from the industrialized countries 6. Discharge Rates can also be encouraged by appropriate incentives. Pump models should be designed for specific ranges of pumping lift, with discharge rates selected accordingly. 4. Standardization For low-lift applications, a high discharge must be Training of caretakers and pump mechanics is compli- achieved, or the pump will not be accepted by users. For cated by the wide variety of pump types that are often high lifts, discharge will necessarily be lower, to ensure used in rural water supply programs. Establishment of that the pump can be operated without excessive effort local manufacturing, enforcement of quality control, and (Box 5.1 in Chapter 5 offers guidance on appropriate effective distribution of spare parts to retail outlets are discharge rates). Two-person operation is increasingly all also hampered. There are clear benefits to be gained advantageous as pumping lift increases. by standardization on one or a few pumps. The issue of Rapid progress should now be possible in the deve- standardization is complex. Manufacturing monopolies lopment of an increasing number of handpumps which may arise, bringing their own problems of quality and can be described as VLOM. The Project will monitor pricing. However, without some standardization, the these developments closely, and is willing to offer advice difficulties of sustaining water supplies to vulnerable low- and comment at any time to those pursuing the incomegroups in rural areasare likelyto be insuperable. objectives outlined in this Chapter. Meanwhile, selection The Project recommends that governments settle on of appropriate handpumps for rural water supply prog- a limited number of pumps for their water programs, and rams must be made from currently available designs. that, when different pumps are in use, efforts should be Chapter 5 describes a methodology for pump made to standardize dimensions, and even spare parts. selection making use of ratings based on each pump's The benefits of such a policy are apparent in India. performance during laboratory and field trials. HANDPUMP TECHNOLOGY 69 Pump Selection Guide In the course of the Project, some 70 handpump models of conditions, therefore, Project staff have frequently have been evaluated (see Annex 2 for a full list). Some had to make "best-judgment" decisions on the basis of are no longer in production; others proved inadequate their own experience and the available field and labo- and were eliminated from further consideration; and ratory evidence. Those judgments have been made in some are included as derivatives of the "parent" pump the confidence that they will be of value to many type (e.g. only one entry is included for the Blair pump, decision makers in developing countries who do not though four variations of the original pump have been have access to the same amount of evidence. The data tested in different countries). The result is detailed source for each pump has been given in the ratings analysis of a total of 42 pump types in this Selection tables, as an indication of the degree of confidence Guide. The Pump Selection Tables include all the pumps which can be attached to the individual ratings. for which the Project has collected sufficient data to enable judgments to be made on their suitability for the How to Use the Pump specified operating conditions, and which are still in Selection Tables production. Extra space is allowed at the bottom of each table for the assessment of unlisted pumps which the In the four Pump Selection Tables at the end of this Analyst' may wish to consider. The Handpump Compen- Chapter, pumps are rated according to the Project's dium, which follows Chapter 6, illustrates the way that assessment of their capability to perform satisfactorily ratings have been assigned to the tested pumps, and in a range of conditions. The combinations of pumping lift may help the Analyst to rate the extra pumps on the and daily output have been chosen to cover most circum- basis of local experience or information published by reli- stances likely to arise in community water supplies in able sources. Some information is provided in Annex 1 developing countries. on a further 17 pumps which have come to the attention Possible applications of the Pump Selection Tables of the Project during the course of the trials, but which include: have not been subjected to the full test procedures. Testing under the Project has involved a combi- * Selection of a single pump to meet the specified nation of field trials and laboratory tests (the test duties and operating conditions of a particular procedures are described in Boxes 1.1 and 1.2 in project or program. Chapter 1), and has yielded extensive data on which to base assessments of the capabilities of each type of * Preparation of a national or regional list of approved pump under a variety of operating conditions. The aim of pumps, based on more generalized operating con- this Selection Guide is to assist water supply planners ditions, as a guide to pump standardization. and designers in developing countries to select appro- priate handpumps for their own specific circumstances. * Compilation of a list of acceptable pumps as part of These circumstances will not always match precisely the procedure for identifying potential suppliers for conditions under which particular pumps have been limited competitive bidding. tested in the field - it would clearly be quite impractical to test all pumps under all possible operating conditions. * Assistance with preparation of bidding documents In assessing likely pump performance over a range and with bid evaluation. 1. Throughout Chapters 5 and 6, the term 'Analyst" is used to Worked examples in Chapter 6 demonstrate typical indicate the individual applying the selection procedures. applications. PUMP SELECTION GUIDE 71 Final selection combines the attributes of the hand- Figure 5.1 Drawdown and Pumping Lift pump itself and the specific conditions of the project or program in which it will be used. Conditions may vary app- reciably from one location to another, and handpumps can only be evaluated for a particular set of conditions. Form 5.1 is a convenient way of listing the con- ditions and should be completed by the Analyst before using the selection tables. Note that some conditions Grundlcvcl are fixed by the planned pump location (e.g. pumping lift, corrosivity of groundwater), while others may be deter- mined by project or country policies (e.g. maintenance system), or by international competitive bidding proce- dures. Guidelines for completion of Form 5.1 follow; a more detailed discussion can be found under the same sub-headings in Chapter 4. Pumping lift Operating Conditions __cas_nayriabl) The appropriate table for pump selection is determined by the anticipated maximum pumping lift. Figure 5.1 illustrates how evaluation of "pumping lift" should allow Pumpingeaterlevel (PWL) for any drawdown which may occur as pumping proceeds. In assessing maximum pumping lift, the Analyst must also take account of possible seasonal or longer term fluctuations in the water table (note that the pumping lift is the distance from the surface to the Wfll depth pumping water level; it is not necessarily related to the cylinder setting or the depth of the well). - Origial well depth Though static water levels may be known, pumping water levels will probably have to be estimated. Draw- Note: In an unconfined aquifer, the static water level in the well down can be calculated with reasonable accuracy if (without pumping) is the water level of the aquifer. After the aquifer permeabilities are known, or determined by pump has been used for some time, the water level in the well will pumping tests. In most geological formations, the sink to the pumping (or dynamic) water level. The difference pumpiowngcaused by handpump discharge . between the two levels depends mainly on the rate of pumping, drawdown caused by handpump discharge rates wil the length of time the pump has been used, and the permeability commonly be less than 5 meters and will rarely exceed of the aquifer (the rate at which the porous medium transmits 10 meters. However, in very low permeability rocks such water). For precision, the pumping lift should be the distance as granites or gneisses drawdown can be very high (see below the discharge level of the pump, but, for convenience, it is Figure 4.2A in Chapter 4), and pumping test data will be usually approximated as the distance below the ground surface. important. The pump groupings in the tables - i.e. 7 meters, 12 "Reliability" ratings (Column 5 of the selection tables) to meters, 25 meters and 45 meters - give an approximate "maximum daily output", the tables allow scope for other guide to the maximum lifts for which manufacturers have demands in addition to domestic drinking water supply to indicated that their pumps may be applicable. be taken into account. If a per capita consumption of 20 As pumping lift increases, so does the effort needed liters/day is assumed, the three output categories to lift water to the surface. For some pumps, the oper- correspond to the following number of users: ating force required soon reaches practical limits and such pumps cannot be considered for high lift appli- 1.5m3/d:equivalentto75usersperpump cations. There are also pumps which will only provide a 4.Om3/d: equivalent to 200 users per pump reliable service when pumping relatively small amounts 8.0m3/d: equivalent to 400 users per pump. of water each day. The Analyst must consider the number of people to (allowances for uses such as irrigation pumping or cattle be served from each handpump and the level of watering will influence the actual number of users). It consumption likely to result (including any potential for must be emphasized that the Project does not recom- small-plot irrigation, animal watering, etc, and taking mend a daily output of 8m3/d as a design criterion, bec- account of any seasonal variations in demand). ause the pump would be operating for many hours each Though the increased costs associated with greater day, resulting in a low level of service because of long depth encourage designers to plan for larger user groups queue times and frequent breakdowns. Ratings have when deep wells are needed, physical laws limit the been included for the higher output, because the amount of water which can be lifted with acceptable demand for such installations is high, and because effort. Per capita consumption is also a critical factor analysis using these ratings can help to identify the affecting the population to be served. By relating the most durable pumps. 72 Box 5.1 The Relationship between Handpump Discharge and Pumping Lift The amount of water which can be obtained from a (oo rating in the selection tables) discharge rates are given handpump depends, theoretically, on three 50% greater than those defined as "adequate" (o factors: the pumping lift; the mechanical efficiency of rating in the selection tables). The better discharge the pump at that lift; and the power input or degree of can be achieved by higher mechanical efficiency effort applied by the pump user. In mathematical and/or better ergonomics encouraging application of terms, the relationship is: more power. The lower discharge rates for higher lifts are an Discharge Power (watts) x Efficiency x 60 important consideration in the rating of pumps for Lift (meters) x 9.81 different operating conditions. Field trial experiences show that pump users put a high premium on the If power and efficiency remained constant, discharge speed with which they can fill their containers, and, would decrease in proportion to increasing lift. This given the choice, will favor a pump giving the highest does not happen in practice, as, for most pumps, discharge, even though it may require more effort than mechanical efficiency improves with increasing alternatives. The Project's assessment of a pump's depth, and users typically apply more effort at higher delivery rate at the specified head is therefore a ruling lifts. factor in the ratings given for discharge adequacy in Figure 5.1A shows the range of discharge rates the Pump Selection Tables S.1 to S.4. which can be expected from a typical range of The right hand axis of the graph in Box Figure pumps, as the pumping lift varies from 7 meters to 60 5.1A shows the discharge rates in cubic meters per meters. "Adequate" discharge rates are based on hour associated with the typical pump range, as normal power inputs ranging from about 50 watts at a pumping lift varies. From this scale, it is simple to cal- culate the number of pumping hours per day needed to Box Figure 5.11A Variations in Pump achieve the daily output figure for each operating con- Box Figure 5.1A Variations In Pump dition. The curves are the basis of ratings assigned to Discharge Rate with Pumping Lift the pumps under the discharge rate heading. For a 7 meter lift (Table S.1), pumps which cannot 30 2.0 achieve a pumping rate of 19 liters per minute are *E 2x deemed unacceptable, even though that implies that E: 25 _ \ _ 1.5 ^ the pumps could deliver the lowest rated daily output Y 20 _ trg 4m3/d). The pump The ratings indicate how easy it would be to under- cannot be recommended for use under such oper- take manufacture of the particular pump in a country with ating conditions where sand ingress is probable. the degree of industrial development denoted by the column 1, 2 or 3. Note that only one rating is given, regardless of the Analysts should note that the presence of foundry intended daily output of the pump. While a - rating and processing skills in the country is not in itself may be acceptable when pumps are only lightly used and enough to ensure that handpumps can be satisfactorily only trace sand pumping is anticipated, Analysts may manufactured locally. Local industry must be willing to prefer to select pumps with at least a o rating for undertake the work and to impose the necessary degree moderate outputs (1.5 to 4m3/d), and look for a oo of quality control. PUMP SELECTION GUIDE 77 Interpretation of the ratings is: from left to right across the appropriate Table, checking the rating in each column that the Analyst has judged to oo The pump can be manufactured to a consistently be relevant. If an unsatisfactory rating appears, the high quality in a country with the specified level of pump is rejected and the next pump examined. Only industrial development (1, 2 or 3). those which match the Analyst's chosen minimum criteria in every column receive a check mark in the o It should be possible to manufacture the pump in the Short List column. country, with some external technical assistance to Further analysis of the shortlisted pumps depends ensure satisfactory quality control, and with impor- upon the purpose of the selection procedure, and is tation of some special materials or components. described in Chapter 6. - Local manufacture of acceptable quality is likely to Prices be impossible to sustain. Indicative ex-factory prices were requested from Fuller details of the manufacturing needs for indivi- manufacturers in February 1985. The prices quoted in dual pumps can be found in the Handpump Compendium. the Handpump Compendium should be taken only as a rough guide to relative capital costs; they cannot be Short List used for estimating purposes. When selecting pumps, up-to-date quotations must be obtained from the This column is provided for the Analyst to develop a manufacturers or distributors, including packing, freight primary selection of pumps which meet the minimum and insurance for the complete pump assembly, with requirements of the project or program under analysis. rods and rising mains to the required depth, and with The selection procedure is to trace each listed pump spare parts if desired. 78 PUMP SELECTION TABLES The ratings in the following tables represent the "best judgment" of the Project staff. They are based in large part on laboratory and/or field data, which are summarized for each pump in the Handpump Compendium which follows Chapter 6. PUMP SELECTION GUIDE 79 _- _* waiting to be repaired. They thus take account of the fact that pumps which are suitable for village maintenance and can be repaired quickly Ratings in the Pump Selection Tables are based on evaluation of pump may be more "reliable" than those which require more complex performance in the laboratory and field trials. Three ratings are used: maintenance, even if the latter break down less frequently. oo = Good o = Adequate - = Does not meet minimum requirements A more detailed interpretation of the ratings for specific headings can be Ratings are based primarily on the materials of the downhole compo- found in the earlier part of this Chapter. nents. Galvanized steel pumprods and rising mains are not corrosion resistant in aggressive water and earn a - rating. The pumps are listed alphabetically in four sections, according to the maximum pumping lift recommended by the manufacturer. The reference Ratings indicate the pump's capability to pump sand-laden water. number which precedes each pump name indicates the order of the Performance in laboratory and field trials is combined with assessment pumps in the Handpump Compendium. of the seal and valve types. For non-suction pumps, leather cupseals are rated - , though the extent of abrasion damage will be related to wffm"11 1*9 W .the daily output of the pump. Analysts may therefore accept lower rated pumps for light duty applications. L = The pump has been tested in the laboratory F = Thepumphashadaminimumof2years'fieldtrials T I 0 (F) = The pump has had limited field trials Ratings indicate the ease with which a pump could be manufactured in a _ _. - developing country with the specified level of industrial development. 1 - Low industrial base, limited quality control 2 - Medium-level industry, no special processes The discharge rate deemed "adequate" for each pumping lift is noted at - Advanced industry, good quality control the top of the appropriate table. The rate reduces as depth increases, for the reasons explained in Box 5.1. Some deepwell pumps thus ,_ ._ _ _ _ _ _ _ _ achieve lower ratings for low-lift applications, where users will opt for pumps giving greater discharges. A special note is made where a pump is available with a range of cylinder sizes or adjustable stroke length, to The Analyst develops a short list by entering a check mark against suit different depths. those pumps meeting his selection criteria. _ * -. _ __ ,. Ratings indicate the ease with which maintenance can be carried out by: Analysts should obtain current prices for short-listed pumps. A - A village caretaker B - An area mechanic C - A mobile maintenance team Special features of individual pumps are noted in this column. * _* Amplification of the notes is given below. Reliability ratings are an indication of the proportion of the time that the pump is likely to be functioning properly. Separate ratings are given for Amplification of the ratings for individual pumps different daily outputs. The ratings combine judgments of the "mean time can be found in the Handpump Compendium before failure" (MTBF) and the probable "downtime" when the pump is e MI W.M1: . The notes relate to pumps with the same reference number - Ie. Note Note 14. The Maldev is a pumphead only. All ratings are based on the 14 refers to Pump 14, the Maldev. In the tables, ratings to which the note use of conventional downhole components. refers are highlighted | Note 16. Reliability ratings for the Monolift are based on pumps with metal gears. Plastic gears were less reliable. Note 1. The oo corrosion rating for the Abi-ASM is based on current Note 21. The oo corrosion rating for the Vergnet is based on current models. Earlier models did suffer from corrosion. models. Earlier models did suffer from corrosion. Note 2. The o corrosion rating for the Afridev is based on the use of Note 23. The oo discharge rating for the Volanta takes account of the stainless steel pumprods, offered as an option. pump's adjustable stroke length. Present designs require a minimum well Note 7. The Duba Tropic 7 is a high-discharge pump designed for two- diameter of 110mm. person operation. Note 30. Downhole components of the Kangaroo are corrosion resis- Notes 9 and 10. The India Mark II uses a gravity return on the tant. The orating relates to the pedal return spring. plunger, and requires a minimum cylinder setting of 24 meters (one Note 40. The Rower is designed as an irrigation pump, and has a high manufacturer offers a fixed-link system for shallower settings). discharge. It is widely used for domestic water supply in Bangladesh. 80 Table S.1 Maximum pumping lift - 7 meters "Adequate" discharge rate -19 liters/minute Ease of Reliability Manufacturing Dta Discharge maintenan'ce for (m3/d -- Corr. Abr. -7needs Short Price Pump name source ~rate AI B IC- 1.5 14 18 res. res. 1 2 3 list (US$) Remarks HIGH LIFT PUMPS (0-45 meters) 1 Abi-ASM L (F) - - 0000 00 0 - oo 0 - 0 SeeNote 1 2 Afridev JF) 0 00 00 00 00 00 0 0 0 0 000 ooISee Note 2 3 AID Deriv. Deepwell L F 00 - 00 00 00 0 - - - - 00 00 4 Bestobell L- 0 *0g 00 00 0 - 0 0 00 00~ 5 Climax L 0oo - - 00 00 00 0 - - - - 00 6 Dragon 2 L 0 - 00 00 00 0 -- - - 0 00_ _ 7 Duba Tropic 7 F 0o* - 0 00 00 0… … … … …Co - - 0 SeeNote 7 8 GSW L2E) o* - 00 00 0oo - - - 0 0 9 India MarklII(standard) L F 0 - 00 00 00 00 00o - - - 0 oo See Note 9 1 0 India Markll1(modified) (FE) 0 - 00 00 oo00 0 0 - o oc See Note 10 1 1 Jetmatic Deepwell L 0 - 00 00 00 000 - - - 0 00 2 Kardia L (F) 0 - 00 00 00000 00 0 - 0 00 1 3 Korat L F 00* - o o 00 00 - - 0o 00 4 Maldev L F 00* - 0000 G 0000 - - 0 00 00 See Notel14 l5 Monarch P3 L F oo0* 00 00 00000 - - - 0 00 6 Monolift L (F) - --000 0000-lo I 00 - - 00 See Notel16 17 Moyno L F - - - 00 00 000 - 00o - - 0 18 NiraAF84 L_ 0 - 00 00 00 00 0O- 00 0 - 0 00 19 Philippines Deepset (j) 0 - o 00 00 00 - I- - 0 00 00 20OSWN 8 & 81 F Oo* 00 00 00 0000 00 00 - 00 00 21 Vergnet L F - 0 o 00 00 00 00 00 0 - 0 0 See Note 21 22 VEW Al8 L 0 - 0 00 00 0 - 0 - - - 0 23 Volanta L F 00 0 00 00 00 00 00 00 00 0 0 00 See Note 23 INTERMEDIATE LIFT PUMPS (0-25 meters) 24 Consallen LD6 IL F OO* - 00 00 00000 00 0 - 0 0 25 DMR(Dempsterderiv.) F OO* - 00 00 00 0 - - - - 00 00 26 NiraAF76 I L F oo* - 00 00 00 0- - - 00o 00 LOW LIFT PUMPS (0-12 meters) 27 BJair F 0 00 00 00 00 0-00 0 0 00 ___ 28 Ethiopia BP50 L 00 0 00 00 00 0 0 0 - 0 00 00 7m max. lift 29 IDRC-UM 00o 0 00 00 00 0 -00 - 0 00 00_ _ 30 Kangaroo *L F 00 - 00 00 00 0 - 0 00 - 0 00 See Note 30 31 Malawi Mark V - F 00 0 00 00 0 - - 00 0 0 00 00 7m max. lift 32 NiraAF85 IL F 00 00 00 00 00 00 00 00 0 0 00 00 33 Tara IL F 00 00 00 00 00 0 - 0 - 0 00 00 SUCTION PUMPS (0-7 meters) 34 AIDSuction F 00 0 00 00 00 0 - - 0 -00 00 35 Banduna L- o 00 .oo oo I 0 0 0 0 0 .oo oo 36lInalsa Suction F 00 0 00 00 00 0 - - - - 0 00 37 Jetmatic Suction jF) 00 0 00 00 00 0 - 0 0 - 00 00 38 Lucky F 00 0 00 00 0 - - - 0 - 00 00 39 New No. 6 L (F) 00 00 00I00 00 0 -- 00- 00 00 40 Rower L (F) 00 0~0 00 OD o I oo . o ee oo 00 See Note 40 41 SYB-100 F 00 0 00 00 00 00l 0 00 Io - 00 00 42 Wasp F 00 0 00 00 00 0- - 0 - 00 00 ADDITIONAL PUMPS Al A2 A3 A4 Indicates that discharge ratings are based on choice of the correct cylinder size from a range offered by the manufacturer. PUMP SELECTION GUIDE 81 waiting to be repaired. They thus take account of the fact that pumps which are suitable for village maintenance and can be repaired quickly Ratings in the Pump Selection Tables are based on evaluation of pump may be more "reliable" than those which require more complex performance in the laboratory and field trials. Three ratings are used: maintenance, even if the latter break down less frequently. oo = Good o = Adequate - = Does not meet minimum requirements A more detailed interpretation of the ratings for specific headings can be Ratings are based primarily on the materials of the downhole compo- found in the earlier part of this Chapter. nents. Galvanized steel pumprods and rising mains are not corrosion resistant in aggressive water and earn a - rating. The pumps are listed alphabetically in four sections, according to the maximum pumping lift recommended by the manufacturer. The reference Ratings indicate the pump's capability to pump sand-laden water. number which precedes each pump name indicates the order of the Performance in laboratory and field trials is combined with assessment pumps in the Handpump Compendium. of the seal and valve types. Leather cupseals are rated - , though the extent of abrasion damage will be related to the daily output of the pump. _ m _- Analysts may therefore accept lower rated pumps for light duty applications. L = The pump has been tested in the laboratory F = The pump has had a minimum of 2 years' field trials [ (F) = The pump has had limited field trials Ratings indicate the ease with which a pump could be manufactured in a developing country with the specified level of industrial development. 1 - Low industrial base, limited quality control The discharge rate deemed "adequate" for each pumping lift is noted at 2 - Medium-level industry, no special processes the top of the appropriate table. The rate reduces as depth increases, 3 - Advancedindustry,goodqualitycontroI for the reasons explained in Box 5.1. Some deepwell pumps thus achieve lower ratings for low-lift applications, where users will opt for pumps giving greater discharges. A special note is made where a pump is available with a range of cylinder sizes or adjustable stroke length, to The Analyst develops a short list by entering a check mark against suit different depths. those pumps meeting his selection criteria. 1"__- !M= Ratings indicate the ease with which maintenance can be carried out by: Analysts should obtain current prices for short-listed pumps. A - A village caretaker B - An area mechanic C - A mobile maintenance team Special features of individual pumps are noted in this column. _ m _* Amplification of the notes is given below. Reliability ratings are an indication of the proportion of the time that the pump is likely to be functioning properly. Separate ratings are given for Amplification of the ratings for individual pumps different daily outputs. The ratings combine judgments of the "mean time can be found in the Handpump Compendium before failure" (MTBF) and the probable "downtime" when the pump is MO3S 6W. M The notes relate to pumps with the same reference number - i.e. Note Note 14. The Maldev is a pumphead only. All ratings are based on the 14 refers to Pump 14, the Maldev. In the tables, ratings to which the note use of conventional downhole components. refers are highlighted |0o Note 16. Reliability ratings for the Monolift are based on pumps with metal gears. Plastic gears were less reliable. Note 1. The oo corrosion rating for the Abi-ASM is based on current Note 21. The oo corrosion rating for the Vergnet is based on current models. Earlier models did suffer from corrosion. models. Earlier models did suffer from corrosion. Note 2. The o corrosion rating for the Afridev is based on the use of Note 23. The oo discharge rating for the Volanta takes account of the stainless steel pumprods, offered as an option. pump's adjustable stroke length. Present designs require a minimum well Note 7. The Duba Tropic 7 is a high-discharge pump designed for two- diameter of 11 Omm. person operation. Note 30. Downhole components of the Kangaroo are corrosion resis- Notes 9 and 10. The India Mark II uses a gravity return on the tant. The o rating relates to the pedal return spring. plunger, and requires a minimum cylinder setting of 24 meters (one manufacturer offers a fixed-link system for shallower settings). 82 rable S.2 Maximum pumping lift - 12 meters "Adequate" discharge rate - 16 liters/minute Ease of Reliability Manufacturing Data Discharge maintenance for (m3/ad Corr. Abr. needs Short Price Pump name source rate A B C 1.5 4 8 res. res. 1 2 3 list (US$) Remarks HIGH LIFT PUMPS (0-45 meters) 1 Abi-ASM L (F) 0 - 00 00 00 - 0 0 0 - 0 0 See Note 1 2 Afridev (F) 00 000000 00 000 0 0 o 0 00 00 See Note 2 3 AID Deriv. Deepwell L F 00 - oo oo oo o - - - - 00 00 4 Bestobell L 0 - o oo oo o- o _ o o o o 5 Climax L oo* - - oo 00 00 0 - …- - 00 6 Dragon 2 L 0 - 0000 00 0 --0 00 __o 7 Duba Tropic 7 F oo* - 0 00 oo o _ … oo See Note 7 8 GSW L (F) o* - oo oo 00 0o -O 9 IndiaMark II (standard) L F 0 - oo 0oo oo oo 0 - _ 0 oo See Note 9 10 India Mark II (modified) (F) 0 - oo oo 0 oo oo oo 0 - 0 00 See Note 10 11 Jetmatic Deepwell L 0 _ 00 oo oo o 0- - 0 00 12Kardia L (F) o 0000 00 00 0 00 0 o0 00 o o 13 Korat LF ooF-* _ oo o oo oo o _ _ oo 14Maldev L F oo* 00 00 oo 00 0 - o oo oo See Note 14 1 5Monarch P3 L F oo* 00 00 00000 - - - 0 00 o _ _ 16 Monolift L (F) 0 --0 oo 00 00 - 00 - - 00 See Note 16 1 7Moyno L F - - 0000 00o0 - o oo - - 0 18 NiraAF84 L 0 - 00 00 oo oo o 00 0 - 0 00 19 Philippines Deepset (F) 0 _ 00 00 00 o - - - 0 00 00 20 SWN 80 & 81 F oo* _ oo o oo oo0 oo 00 0 oo oo 21 Veranet L F - 0 00 00 oo oo o oo o - o o See Note 21 22 VEW A18 L 0 - 0 00 00 - 0 0 oo _ o 23 Volanta L F 00 0 00 00 00 00 00 00 oo o o 00 See Note 23 INTERMEDIATE LIFT PUMPS (0-25 meters) 24 Consallen LD6 L F oo* _ oo oo 00 0- 0 0 0 - 0 00 25 DMR(Dempsterderiv.) F oo* _ oo oo 00 0 - - 00 00 _oo 26 NiraAF76 L F oo* - oo oo oo 0 - 0 - ooo0 oo LOW LIFT PUMPS (0-12 meters) 27 Blair F 0 goo o _ oog g o oo 28 Ethiopia BP50 L _ 7m max. lift 29 IDRC-UM L 00 0 0000 00 0 00 - 0 00 00 30 Kangaroo L F 00 - 00 00 00 0 _ 00 - 0 00 See Note30 31 Malawi Mark V F 7m max. lift 32 NiraAF85 L F 00 oo oo 00 00 000 00 0 0 00 00 33 Tara L F 00 00 0000 0 - - 0 - 0 00 00 ADDITIONAL PUMPS Al A2 A3 = == == A4 _____ Indicates that discharge ratings are based on choice of the correct cylinder size from a range offered by the manufacturer. PUMP SELECTION GUIDE 83 mm = _Ml :1; YA I _ R- waiting to be repaired. They thus take account of the fact that pump which are suitable for village maintenance and can be repaired quickl Ratings in the Pump Selection Tables are based on evaluation of pump may be more "reliable" than those which require more comple performance in the laboratory and field trials. Three ratings are used: maintenance, even if the latter break down less frequently. oo = Good o = Adequate - = Does not meet minimum requirements A more detailed interpretation of the ratings for specific headings can be Ratings are based primarily on the materials of the downhole compi found in the earlier part of this Chapter. nents. Galvanized steel pumprods and rising mains are not corrosio resistant in aggressive water and earn a - rating. The pumps are listed alphabetically in four sections, according to the maximum pumping lift recommended by the manufacturer. The reference Ratings indicate the pump's capability to pump sand-laden wate number which precedes each pump name indicates the order of the Performance in laboratory and field trials is combined with assessmer pumps in the Handpump Compendium. of the seal and valve types. Leather cupseals are rated - , though th extent of abrasion damage will be related to the daily output of the puml Analysts may therefore accept lower rated pumps for light dul applications. L = The pump has been tested in the laboratory F = Thepumphashadaminimumof2years'fieldtrials 4 (F) = The pump has had limited field trials Ratings indicate the ease with which a pump could be manufactured in *MM IN SIM1. ". *.developing country with the specified level of industrial development. 1 - Low industrial base, limited quality control 2 - Medium-level industry, no special processes The discharge rate deemed "adequate" for each pumping lift is noted at - Advancediindustry, goodqualitycontrol the top of the appropriate table. The rate reduces as depth increases, for the reasons explained in Box 5.1. Some deepwell pumps thus achieve lower ratings for low-lift applications, where users will opt for pumps giving greater discharges. A special note is made where a pump is available with a range of cylinder sizes or adjustable stroke length, to The Analyst develops a short list by entering a check mark again! suit different depths. those pumps meeting his selection criteria. * - . 0 e .e - M Ratings indicate the ease with which maintenance can be carried out by: Analysts should obtain current prices for short-listed pumps. A - A village caretaker B - An area mechanic C - A mobile maintenance team Special features of individual pumps are noted in this columr .0MI'M 'O Amplification of the notes is given below. Reliability ratings are an indication of the proportion of the time that the pump is likely to be functioning properly. Separate ratings are given for Amplification of the ratings for individual pumps different daily outputs. The ratings combine judgments of the "mean time can be found in the Handpump Compendium before failure" (MTBF) and the probable "downtime" when the pump is The notes relate to pumps with the same reference number - i.e. Note person operation. 14 refers to Pump 14, the Maldev. In the tables, ratings to which the note Note 14. The Maldev is a pumphead only. All ratings are based on th refers are highlighted | j o use of conventional downhole components. Note 16. Reliability ratings for the Monolift are based on pumps wit Note 1. The oo corrosion rating for the Abi-ASM is based on current metal gears. Plastic gears were less reliable. models. Earliermodelsdidsufferfromcorrosion. Note 21. The oo corrosion rating for the Vergnet is based on currer Note 2. The o corrosion rating for the Afridev is based on the use of models. Earlier models did suffer from corrosion. stainless steel pumprods, offered as an option. Note 23. The oo discharge rating for the Volanta takes account of th Note 7. The Duba Tropic 7 is a high-discharge pump designed for two- pump's adjustable stroke length. Present designs require a minimum we diameter of 11 Omm. 84 Table S.3 Maximum pumping lift - 25 meters "Adequate" discharge rate - 10 liters/minute Ease of Reliability Manufacturing Data Discharge maintenance for (m36dL Corr. Abr. needs Short Price Pump name source rate A B C 4 8 res. res. I 2 3 list (US$) Remarks HIGH LIFT PUMPS (0-45 meters) 1 Abi-ASM L (F) 0 - 00 00 0 - 00 0 0 0 See Note 1 2 Afridev (F) 00 00 00 00 00 0 0 0 0 00 00 See Note 2 3 AID Deriv. Deepwell L F 0 - 0 00 - - - - - 00 00 4 Bestobell L 0 - 0 oo 0 - o o o oo oo 5 Climax L 0o* _ - 00 00 0 - - - -00 6 Dragon 2 L 0 - 0 00 - - _0 00 7 Duba Tropic 7 F oo* - 0o 00 0 - _ _ -00 See Note 7 8 GSW L (F) oo* _ o o o - _ 9 India Mark 11 (standard) L F 00 _ 0 00 0 - _ _ _ 0 00 10 India Mark II (modified) (F) oo - 00 00 00 0 - 0 00 11 Jetmatic Deeowell L 0 - 0 00 - - _ - _ 0 00 12 Kardia L (F) oo - 0000 0 - 00 0 o0 00 13 Korat L F o0* - o oo o - - oo oo 14 Maldev L F 00* - 0 00 o - - oo o o _ See Note 14 15 Monarch P3* L F 00 - o oo 0 - - _0 00 o o 16 Monolift L (F) o - - oo 00 o - oo _- 00 See Note 16 17 Moyno L F 0 - - 00 00 0 - oo - - 0 18 NiraAF84 L 0 - 0 00 00 0 00 0 - o 00 19 Philippines Deepset (F) 00 - 0 00 0 - - 0 00 00 20 SWN 80 & 81 F oo* - 0 00 0 - 00 00o - 00 00 21 Verqnet L F o 0 0000 00 0 00 0 - 0 o See Note 21 22 VEWA18 L 0 -- 0 0 0 - 00 - - _ - 0 23 Volanta L F 00 0 00 00 o0 00 00 00 0 0 00 See Note 23 INTERMEDIATE LIFT PUMPS (0-25 meters) 24 Consallen LD6 L F oo* - 00 00 - - 00 o 0 00 25 DMR(Dempsterderiv.) F oo* - 0 00 - - - _ - 00 00 26 NiraAF76 L F oo* - 0 00- - - 0- 000 ADDITIONAL PUMPS Al A2 A3 = _ __ A4 _ * Indicates that discharge ratings are based on choice of the correct cylinder size from a range offered by the manufacturer. PUMP SELECTION GUIDE 85 _ _ waiting to be repaired. They thus take account of the fact that pump which are suitable for village maintenance and can be repaired quickl Ratings in the Pump Selection Tables are based on evaluation of pump may be more "reliable" than throse which require more comple performance in the laboratory and field trials. Three ratings are used: maintenance, even if the latter break down less frequently. oo = Good o = Adequate -- _ - = Does not meet minimum requirements A more detailed interpretation of the ratings for specific headings can be Ratings are based primarily on the materials of the downhole compc found in the earlier part of this Chapter. nents. Galvanized steel pumprods and rising mains are not corrosio resistant in aggressive water and earn a - rating. The pumps are listed alphabetically in four sections, according to the maximum pumping lift recommended by the manufacturer. The reference Ratings indicate the pump's capability to pump sand-laden wate number which precedes each pump name indicates the order of the Performance in laboratory and field trials is combined with assessmer pumps in the Handpump Compendium. of the seal and valve types. Leather cupseals are rated - , though th extent of abrasion damage will be related to the daily output of the pump RM* SIRM W _ Analysts may therefore accept lower rated pumps for light duf applications. L = The pump has been tested in the laboratory F = Thepumphashadaminimumof2years'fieldtrials 5 (F) = The pump has had limited field trials Ratings indicate the ease with which a pump could be manufactured in _ _*.. developing country with the specified level of industrial development. 1 - Low industrial base, limited quality control 2 - Medium-level industry, no special processes The discharge rate deemed "adequate" for each pumping lift is noted at 2 - Advanced industry, good quality control the top of the appropriate table. The rate reduces as depth increases, for the reasons explained in Box 5.1. Some deepwell pumps thus ____ achieve lower ratings for low-lift applications, where users will opt for pumps giving greater discharges. A special note is made where a pump is available with a range of cylinder sizes or adjustable stroke length, to The Analyst develops a short list by entering a check mark agaim suit different depths. those pumps meeting his selection criteria. Ratings indicate the ease with which maintenance can be carried out by: Analysts should obtain current prices for short-listed pumps. A - A village caretaker B - An area mechanic C - A mobile maintenance team Special features of individual pumps are noted in this columr -- ** Amplification of the notes is given below. Reliability ratings are an indication of the proportion of the time that the pump is likely to be functioning properly. Separate ratings are given for Amplification of the ratings for individual pumps different daily outputs. The ratings combine judgments of the "mean time can be found in the Handpump Compendium before failure" (MTBF) and the probable "downtime" when the pump is M ! T.S - The notes relate to pumps with the same reference number - i.e. Note Note 12. The manufacturer recommends a maximum depth of 4' 14 refers to Pump 14, the Maldev. In the tables, ratings to which the note meters for the Kardia refers are highlighted Note 14. The Maldev is a pumphead only. All ratings are based on th. use of conventional downhole components. Note 16. Reliability ratings for the Monolift are based on pumps witi metal gears. Plastic gears were less reliable. A 2:1 gear ratio is suppliei Note 1. The oo corrosion rating for the Abi-ASM Is based on current for deepwell applications. models. Earlier models did suffer from corrosion. Note21Te app corroion rr Note 2. The o corrosion rating for the Afridev is based on the use of models. Earlier modelsdid sufferng for the Vergnet is based on currer stainless steel pumprods, offered as an option. Notel2. The m e dischar ran forrteiont Note 7. The Duba Tropic 7 is a high-discharge pump designed for two- pump's adustable stroke length Pre the Volanta takes account of thi person operation. diameter of 11 Omm. 86 Table S.4 Maximum pumping lift - 45 meters "Adequate" discharge rate - 7 liters/minute _I - - - _n-U Ease of Reliability Manufacturing Data Discharge maintenance for (m3/dj Corr. Abr. needs Short Price Pump name source rate A B C 4 res. res. 1 2 3 list (US$) Remarks HIGH LIFT PUMPS (0-45 meters) 1 Abi-ASM L (F) 0 _ ao 00 - 0 0 - 0 0 See Note 1 2 Afridev (F) 00 00 00 00 0 0 0 0 00 00 See Note 2 3 AID Deriv. Deepwell L F 0 - 0 00 - - - - 00 00 4 Bestobell L 0 - I oo - o o o oo oo 5 Climax L oo* - - 00 0 - - - - 00 6 Draaon 2 L 0 - 0 00 _ _ _ - 0 00 7 Duba Tropic 7 F o0* - 0 00 - _ -00 See Note 7 8 GSW L (F) oo* - o oo _ _0 _ 9 India Mark 11 (standard) L F 00 0 00 - o o _o 00 10 India Mark 11 (modified) (F) oo _ 00 00 0 o0 - 0 00 11 Jetmatic Deepwell L 00 0 00 - - - 0 00 12 Kardia L (F) oo - o oo - |oo 0 - 0 00 See Note 12 13 Korat L F oo* _ - _ 0 oo Ioo 14 Maldev L F oo - 0 00 - _ _ oo oo See Note 14 15 Monarch P3 L F oo* - 0 00 - _ - o oo 16Monolift L (F) 0 -- 0 0 0 00 - - 00 See Note 16 17 Moyno L F 0 - -00 0 00 - - 0 18 NiraAF84 L 0 - 0 00 0 00 0 - 0 00 19 Philippines Deepset (F) o0 - 0 00 - - - 0 00 00 20 SWN 80 & 81 F oo* - 0 00 - 00 00 - 00 00 21 Verpnet L F 0 0 oo00 0 00 0 - 0 0 See Note 21 22 VEWA18 L 0 - - 00 - 00 - - - 0 23 Volanta L F oo 0 0000 0 00 00 Io0 0 00 See Note 23 ADDITIONAL PUMPS Al A2 A3 A4 * Indicates that discharge ratings are based on choice of the correct cylinder size from a range offered by the manufacturer. PUMP SELECTION GUIDE 87 Pump Selection: Worked Examples The Pump Selection Tables in Chapter 5 can be used to pumps. Information in the Compendium should be make a short list of pumps which meet minimum require- supplemented by up-to-date information on pump prices, ments. Together with the Handpump Compendium, they including freight and insurance, and, where appropriate provide a means of selecting a pump for one particular by inspection of working pumps and manufacturing application. facilities, or by review of working drawings of non- The tables can also be used as an aid to preparation proprietary pumps with potential local manufacturers. of bidding documents or to evaluation of bids for the The examples which follow demonstrate how the procurement of handpumps. Draft Sample Bidding Pump Selection Tables can be used to develop a short Documents for the Procurement of Handpumps1, desig- list of pumps. They are followed by a brief description of ned for international competitive bidding, may also be the merit point method of pump evaluation used in the used and are available from the World Bank. They sample bidding documents. include methods for weighting key pump attributes, so that the benefits of exceeding minimum requirements Worked Example No 1: Low Lift (better reliability, easier maintenance, etc.) can be taken into account alongside price. This example is typical of an alluvial plain in Asia, with a Final selection of one or more pumps will depend on permeable aquifer and a high groundwater level. A the operating conditions under which the pumps will be maximum user group of 75 people per handpump is used, the relative importance placed on different desired, with a demand of 20 liters per person per day selection criteria, and up-to-date prices. In selecting (i.e. each pump must supply 1.5 cubic meters of water a handpumps for a particular application, the important day). Very little drawdown is expected during pumping, first step is a clear definition of the operating but nearby motorized pumps may lower the water table conditions (i.e. the range of pumping lifts, the amount locally in some areas to 10 meters below the surface. of water to be pumped each day, the corrosivity of the The groundwater is not corrosive, and only trace water and the potential for sand pumping), the amounts of sand may enter the wells during pumping. maintenance system that will be employed, and the Village-level maintenance is to be introduced, as is in- importance placed on local manufacture. country manufacture of handpumps, in a country with a Form 5.1 at the beginning of Chapter 5 is a medium level industrial base. Two pumps are already convenient way of establishing these pump selection widely used in the country - The India Mark I1 (imported) criteria. These minimum requirements then permit the and the New No 6 (locally made). Analyst to identify the appropriate Pump Selection Table, and then to eliminate from further consideration The first step in selecting a short list of pumps for this those pumps which would be unsuitable. The resulting application is to complete Form 5.1 with the specific Short List of pumps may then be evaluated in more Selection Criteria. Figure 6.1 includes a copy of the form detail. completed according to the criteria identified by the The Handpump Compendium is provided as a Analyst. Note that there is no Pump Selection Table reference for more detailed analysis of shortlisted precisely matching the operating condition of 10 meters maximum pumping lift, so the Analyst opts for Table S.2 (12 meters), ensuring that the most severe conditions 1. Applied Research and Technology - Note No. 1, Draft are met. Sample Bidding Documents for the Procurement of Handpumps, From the criteria listed on Form 5.1, the Analyst World Bank, 1986.FrmtecieilitdoFom51thAnys determines that for a pump to meet his minimum 89 Figure 6.1 Handpump Selection Criteria for Worked Example No. 1 HANDPUMP SELECTION CRITERIA NAME OF PROJECT Worked Example No.1 MAXIMUM PUMPING LIFT 10 meters Selection Table for this lift, S.2 DAILY OUTPUT PER PUMP 1.5 m3/d MAINTENANCE SYSTEM TO BE USED (A, B, or C) A Where A = Village-level maintenance B = Area-mechanicmaintenance C = Centralized maintenance MINIMUM RATING NEEDED FOR CORROSION RESISTANCE Where - = Corrosion resistance is not required o = Resistance to mildly corrosive water is required oo = Resistance to aggressive water is required MINIMUM RATING NEEDED FOR ABRASION RESISTANCE Where -= Either there is no sand pumping anticipated, or there is a possibility of trace sand pumping and the daily output will not be greater than 1 .5m3 o = There is a possibility of trace sand pumping and the daily output will be greater than 1 .5m3 oo = There is a possibility of significant sand pumping MANUFACTURING ENVIRONMENT (1, 2, or 3) 2 Where 1 = The pump is to be made in the country, and there is a low-level industrial base 2 = The pump is to be made in the country, and there is a medium-level industrial base 3 = The pump may be imported or made in a country where there is a high level industrial base PUMPS ALREADY PERFORMING SATISFACTORILY IN THE New No.6* COUNTRY (* IF ALSO MANUFACTURED IN THE COUNTRY) India Mark II 90 requirements it must achieve ratings in Table S.2 as mechanics, perhaps travelling on mopeds or bicycles. follows: Good quality control of drilling and well construction can be assured, to prevent sand pumping, and the ground- water is not corrosive. In-country manufacture is not an Column No. Criterion Minimum immediate objective. in Table S.2 Rating In completing the Selection Criteria Form for this 3 Discharge rate o application (Figure 6.3 Examples 2 and 3), it is prudent to consider two separate cases - one for the 25 meter lift 4(A) Ease of maintenance specified for the project itself, and the other covering at village level o anticipated conditions in the nearby area, where pumps may be needed in the future, and standardization would 5(1.5) Reliabilityforoutput be of benefit. The Analyst will perform his evaluation of 1.5m3/day o using Table S.3 for the project area and Table S.4 for the proximate area. Figure 6.3 (Examples 2 and 3) shows 6 Corrosion resistance - the completed Forms, resulting in two Short Lists. Sixteen pumps make the short list in Example 2 7 Abrasion resistance - (25m pumping lift) while only 5 make it in Example 3 (40m lift). The large list for Example 2 reflects the fact that 8 (2) Manufacturing needs in trained area mechanics can successfully remove the medium-level industrial base o pumping element of most conventional handpumps at pumping lifts down to 25 meters with no external assis- Each of the pumps in Table S.2 is evaluated, to tance. However, at higher pumping lifts, this is not the check whether it achieves these minimum ratings. Figure case, and reliability becomes unacceptable for most 6.2 shows the completed Table S.2, revealing that just pumps. The short list for Example 3 is therefore more six pumps met the minimum requirements (the desire for limited. village-level maintenance and local manufacture elimi- When selecting a pump for this region, special nates many on the list). Neither of the pumps currently in consideration should be given to those pumpqwhich are use in the country make the Short List - the New No. 6 on both lists, so as to choose a single high-lift pump is a suction pump and so cannot be considered for lifts model for the region. of more than 7 meters, and the India Mark II is not appropriate for village-level maintenance. The six short- listed pumps therefore are: the Afridev, Blair, IDRC- Worked Example No. 4: VLOM Pumps UM, Nira AF85, Tara and Volanta. for Intermediate and High Lifts This narrowing of the choice is a very important step in the selection process, as it produces a manageable Example No. 4 identifies those intermediate (12-25m) list for detailed analysis in the final selection stage. In and high (25-45) lift pumps (Afridev and Volanta) that this particular example, further reduction of the short list are most likely to be able to be maintained by village- will depend on the priority given to individual attributes, based repairers, and that can be manufactured in and on prices. For example, the Blair has a lower rating countries with a low industrial base. Both the short list (o) than the others (oo) for discharge, the IDRC-UM pumps have limitations: the Afridev has only limited and Volanta lower ratings for ease of maintenance, and field performance data (as indicated by (F) under Data the Tara a lower rating for reliability. Five of the pumps Source in the rating tables), and is still undergoing rank equally (oo) for local manufacture, which in this development, as the Compendium entry (Pump 02) case is an important criterion. Consequently, potential makes clear; the Volanta requires a 110mm I.D. well manufacturers in the country should be contacted to casing, ruling out its use in 100mm wells. A small obtain assessments of their capacities for manufac- diameter version of the Volanta is now being tested turing the six pumps under consideration, and the prices (See Note 23 in the rating tables). The requirements of for doing so with adequate quality control. village-based maintenance and local manufacture used in this example lead to a very limited short list, an Worked Examples Nos. 2 & 3: indication of the importance of present and future Intermediate and High Lift development of VLOM pumps for medium and high lift applications. A handpump program is being prepared for a region where maximum pumping lift, including drawdown during Merit Point Evaluation the pumping day, is expected to be 25 meters for the majority of the wells (Example No. 2), though lifts in Whether or not full competitive bidding procedures and areas near to the project may be as much as 40 meters (Example No. 3). Each pump is to supply 200 people with In this example, the only water use will be domestic, but the 20 liters a day - giving a total daily output of 4r3*. The Analyst is cautioned that in some other cases allowance must pump must be suitable for maintenance by area also be made for animal watering or irrigation. PUMP SELECTION: WORKED EXAMPLES 91 Figure 6.2 Compilation of Short List for Worked Example No.1 Table S.2 Maximum pumping lift - 12 meters "Adequate" discharge rate - 16 liters/Minut( A S~~E Ease of Reliability Manufacturing Data Discharge maintenan'ce for (m3/d) Corr. Abr. needs Short Price Pump name source rate A B C .548res. res. 1 2 13 list (US$) Remarks HIGH LIFT PUMPS (0-45 meters) l Abi-ASM L F 0 - 0 0000 0- 00 0 - 0 0 __See Notel1 2 Afridev (F) 00 0 00 00 00010 0 0 00 00 __ See Note 2 3 AID Deriv. Deepwell L F 00 - 00 00 00 0- - 00 00 __ 4 Betoel j 0 - 0 0 00 A. 0 0 .Q 0 00 ____ 5 Climax . .L oo* -009 00 000 - 00 __ 6 Dragon 2 L 0 - 00 00 00 0 - 0 00__ 7 Duba Tropic 7 F oow - 00 00 0 … … … 00 _ _See Note 7 8 GSW ~ L EF o* 00 no 00 00 0 - -OQ 9 India Markl11(standard) L F 0 - 00 --Po g 00 00 Co. 0 00 See Mote 9 1 0India Markll1(modified) (E1 0 - 00 00q 00 00 00 - 0 - 0 0___ See NotelO 1 1Jetmatic Deep~well L 0 - 00 00 00 00 0 - - - 0 00 __ 1 2Kardia LF) 0 - 00 00 00 00 0 00 0 - 0 00 1 3Korat L F oo* 0g. J- 00 00 - 00 00 l 4Maldev L F oo* Do 00 oo00 000 - 0 00 _____ See Note14 l5 Monarch P3 L F oo* oo I000 00 000 - - - 0 00 1 6Monolift L (F 0 - -0000 000- 00 - -00 See Note 16 17 Moyno L F - - - 0000o 000 00 - - 0__ 1 8NiraAF84 L 0 - 00 00 00 00 0 00 0 - 0 00___ 1 9Philippines Deepset (F 0 - 00 00 00 0 - - - 0 00 00_____________ 20OSWN 8 & 81 F 00* - 00 00 00 0000 00 00 - 00 00__ 21 Veronet L F - 0 00 00 00 000 00 0 0 0__ SeeNote 21 22 VEWA18 L 0 - 0 00 00 0 - 00 - o __ __ 23 Volanta L F 00 0 o o 00 00 0 0000 00 0o 0 00 See Note 23 INTERMEDIATE LIFT PUMPS (0-25 meters) 24 Consallen LD6 1 L F oo* - 0000o 00 0-00 0 - 0 00__ 25 DMR(Dempsterderiv.) F oo' - 00 ao 00 0 -- - - 00 00___ 26 NiraAF76 ]L F oo* 00 00 00 0-- 0 - 00 00__ LOW LIFT PUMPS (0.12 meters) 27 Blair F 0 oo oo oo oo. 0- oo o o9 ooI .0 ' __ 28 Ethiopia BP50 L I I7m max. liff 29lIDRC-UM L 00 0 00 00 00 0- 00 - 0 00 00 ____ 30 Kangaroo L F 00 - -00 00 00 0- 0 00 - 0 00 See Note 30 31 Malawi Mark V F I I 7m max. lift 32 NiraAF85 L F 00 00 00 00 00 000 00 0 0 00 00 1_ ___ 33 Tara L F 00 00 00 00 0 -- 0 - 0 00 00 ADDITIONAL PUMPS Al A2 A3__ _ _ A4 _ _ _ _ _ _ *Indicates that discharge ratings are based on choice of the correct cylinder size from a range off ered by the manufacturer. 92 Figure 6.3 Selection Criteria and Shortlisted Pumps for Worked Examples Nos. 1-4 HANDPUMP SELECTION CRITERIA CTION_CRITERIA CTION CRITERIA _______________NCRTEI NAME OF PROJECT Worked Example No. 1 WN CRITERIA Worked Example No. 2 ECTION CRITERIA MAXIMUM PUMPING LIFT 10 meters 2ork d Example No.3 Selection Table for this lift 252 24 meters Worked ExamRle No. 4 S.3 40 meters DAILY OUTPUT PER PUMP t.5 m3/d S3 25 or 45 meters 4 M3/d S.3 or S.4 MAINTENANCE SYSTEM TO BE USED (A, B, or C) A 4 mn3md Where A = Village-level maintenance B 4 M3Bd B = Area-mechanic maintenance B C = Centralized maintenance A MINIMUM RATING NEEDED FOR CORROSION RESISTANCE - Where - = Corrosion resistance is not required TANCE o = Resistance to mildly corrosive water is required ed E TANCE oo = Resistance to aggressive water is required ter is required NCE s required required jired MINIMUM RATING NEEDED FOR ABRASION RESISTANCE - ired ater is required Where - = Eitherthereis nosand pumpinganticipated, or NCE is required there is a possibility of trace sand pumping and anticipated, or the daily output will not be greater than 1 .5m3 and pumping and ated, or sANCE o = There is apossibilityof trace sand pumping and ater than 1.5m3 humping and sand pumping and the daily output will be greater than 1 .5m3 d pumping and han 1.5m3 reater than 1.5M3 oo = There is a possibility of significant sand pumping r than 1.5m3 iping and nd pumping and itsand pumping 1.5m3 erthan 1.5m3 MANUFACTURING ENVIRONMENT (1,2, or3) 2 3 pumping nt sand pumping Where 1 = The pump is to be made in the country, and there 3 is a low-level industrial base untry, and there and there untry, and there 2 = The pump is to be made in the country, and there , is a medium-level industrial base untry, and there and there untry, and there 3 = Thepumpmaybeimportedormadeinacountry ase n where there is a high level industrial base ade in a country base lustrial base ia country Tade in a country PUMPS ALREADY PERFORMING SATISFACTORILY IN THE New No.6* I base ustrial base COUNTRY (' IF ALSO MANUFACTURED IN THE COUNTRY) India Mark II q THE N.A. TRY) N.A. IN THE N.A. CRITERIA FOR Pumping lift:, 12 meters 25 meters 45 meters 25m or45m WORKED Maintenance system: VLOM Area Mechanic Area Mechanic VLOM EXAMPLES Industrialbase: Medium Advanced Advanced Low Abi-ASM, Afridev, Bestobell, Duba Tropic 7, GSW, India Mark il (std. & mod.), Kardia, Korat, Maidev, Monarch P3, Affidev, PUMPS WHICH MEETTHE Afridev, Blair, Nira AF84, Philippines India Mark II (mod.), ILLUSTRATED SELECTION IDRC-UM, Nira AF85, Deepset, SWN 80&81, Nira AF84, Vergnet, Afridev CRITERIA Tara, Volanta Vergnet, Volanta Volanta Volanta merit point evaluation are to be used for final pump to that outlined in the World Bank's sample bidding selection, up-to-date prices are essential. The prices documents, where minimum requirements are specified quoted in this document cannot be used for final stage and merit points are then awarded to those pumps which comparisons; they are indicative of ex-factory prices exceed the minimum requirements (ease of maintenance only and they were obtained in 1985 and 1986. For pump and availability of spare parts are examples of attributes selection, the Analyst must have current prices, which may be awarded additional merit points). including shipping and insurance costs for the quantities The full procedures of Merit Point Evaluation require needed, and must take account of the anticipated cost lengthy explanation, and Analysts wishing to apply this of spare parts over a reasonable period of operation (say method are advised to obtain a copy of the World Bank's three years). The Handpump Compendium offers Sample Bidding Documents for the Procurement of guidance on likely frequency of repairs, and experiences Handpumps. Table 6.1 shows the outcome of such an from other projects may also provide data for assessing evaluation comparing four pumps which met all minimum pump performance and spares requirements. requirements. From this evaluation, Pump "B" would be Some Analysts may have decided to select the selected, because it has the highest total merit point least expensive pump which meets the minimum score among the short-listed pumps, though it was not requirements. Others may be using a procedure similar the lowest priced pump (thatwas Pump "C"). Table 6.1 Merit Point Evaluation of Four Short-Listed Pumps Maximum Pump reference Criterion score A B C D Price of pump 50 32 42 50 34 Price of spare parts 10 6 8 9 10 Discharge rate* 5 0 5 3 0 Reliability* 10 5 7 5 5 Ease of maintenance and repair* 10 8 8 4 4 Service and spare parts availability* 5 0 3 0 0 Abrasion resistance* 5 0 3 0 3 Standardization 5 0 5 0 0 Total Scores 100 51 81 71 56 * Denotes categories for which merit points may be awarded if a pump exceeds the minimum requirement. A zero entry means that a pump just meets the minimum requirement. 94 Handpump Compendium Handpump Compendium The Compendium contains details of the following pumps: Pump 01 Abi-ASM Pump 22 VEW A18 Pump 02 Afridev Pump 23 Volanta Pump 03 AID Derivative Deepwell Pump 24 Consallen LD6 Pump 04 Bestobell Pump 25 DMR (Dempster Derivative) Pump 05 Climax Pump 26 Nira AF76 Pump 06 Dragon 2 Pump 27 Blair Pump 07 Duba Tropic 7 Pump 28 Ethiopia BP50 Pump 08 GSW Pump 29 IDRC-UM Pump 09 India Mark II (standard) Pump 30 Kangaroo Pump 10 India Mark II (modified) Pump 31 Malawi Mark V Pump 11 Jetmatic Deepwell Pump 32 Nira AF85 Pump 12 Kardia Pump 33 Tara Pump 13 Korat Pump 34 AID Suction Pump 14 Maldev Pump 35 Bandung Pump 15 Monarch P3 Pump 36 Inalsa Suction Pump 16 Monolift Pump 37 Jetmatic Suction Pump 17 Moyno Pump 38 Lucky Pump 18 Nira AF 84 Pump 39 New No.6 Pump 19 Philippines Deepset Pump 40 Rower Pump 20 SWN 80 & 81 Pump 41 SYB-100 Pump 21 Vergnet Pump 42 Wasp Cote d'lvoire/France Laboratory Tests Date tested: 1982 Reported: Handpumps Project Report No. 3 Performance data (typical values) -/57 Head (meters) 7 25 45 Pumping rate (cycles/min) 38 40 42 Volume/min (liters) 10 10 10 Input (watts) 82 129 175 Mechanical efficiency (%) 14 32 43 Maximum handle force (kg-f) 20 35 45 Foolvalve leakage (mimini No signiticant leakage The volume discharged per stroke ranged from 0.25 liters at 45 meters lift to 0.27 liters at 7meters lift. Evaluation enced with the above ground components, Y e The two test pumps were well packed, but the below ground pumping element suff- had suffered some damage. Threads on ered no breakdowns and was still in good the pumphead base were damaged on one working order at the end of the 4000 of the samples, and the baseplates were hours. distorted on both. Handle components Repeated failure of the primary cyl- General Description were not correctly aligned on either pump. inder plunger seals was attributed to sharp Comprehensive and well illustrated edges detected on the replenishing hole in The Abi-ASM is a hybrid pump using a installation and maintenance instruc- the cylinder. The hole had not been pumpstand manufactured in the Cote tions were supplied in French. Insta- properly deburred during manufacture - a d'lvoire and the hydraulically operated llation is straightforward and does not difficult operation because of the position Vergnet pumping element made in France require lifting tackle. Lightweight poly- of the hole. (Pump 21). There are no mechanical links ethylene hoses connect the pumpstand The manufacturer has changed the between the above and below ground with the pumping element. design of the fulcrum and the pumprod units. A primary cylinder in the pumpstand Maintenance too is simple. fixing since the laboratory tests. is connected by plastic hose to a stain- Primary cylinder piston seals are likely to Corrosion was detected on the less steel casing, in which a flexible need frequent replacement, but the task is plunger rod and the pumping element end rubber membrane contracts and expands straighfforward and quick. The lightweight caps, and inside the pumpstand. to force water through a second hose to hoses mean that the pumping element can Both the pumpstand and the handle the surface. be extracted by hand, without lifting were undamaged in the impact tests, and The pumpstand is partly cast iron tackle, and the element itself is easy to the pump completed the allotted 96,000 and partly fabricated mild steel. Fulcrum dismantle provided the appropriate hexa- cycles of handle shock tests without bearings are split and injection molded in gon keys are available. However, if the failure. nylon. Brass or stainless steel is used for diaphragm fails, a full replacement unit is Users quickly became accustomed the primary drive cylinder and the brass needed, at comparatively high cost. to the rhythm required to operate the plunger has leather ring seals. The 4000 hour endurance test pump, but found it tiring to use because of was carried out at 40 cycles per minute, the comparatively low discharge rate and Manufacture with a simulated head of 45 meters, high efforts needed. The pumpstand is suitable for manufac- subsequently reduced to 20 meters. The The overall conclusion of the labor- ture in developing countries with foundry, original leather seals on the primary cyl- atory trials was that there is a marked fabrication and machining skills, and could inder plunger wore out very early in the contrast between the reliability of the be modified for all-fabricated manufacture. test. They were replaced with seals of pumpstand and above ground works and The below-ground pumping element different materials but continued to wear that of the below-ground pumping element. requires specialized techniques, high skill out rapidly. The fulcrum in the handle wore While the pumping element proved very levels and high quality control. out after about a third of the test period reliable, the pumpstand was judged to be and the bolt securing the drive piston rod unsuitable for community water supply. Suppliers to the fulcrum broke at about the same Modifications have since been made to Abidjan Industrie, 01 BP 343, Abidjan, 01 time. About half way through the endu- the pumpstand. If the problems can be Cote d'lvoire. rance test, the rubber buffer in the plunger overcome, the Abi-ASM is seen as a was found to have collapsed and was potential VLOM pump because of its Indicative prices - Feb 1985 replaced. simple installation and maintenance In contrast with the problems experi- requirements. Per unit US$ 690 Twin hose (per meter) US$ 3 98 PUMP 01 Field Trials Test conditions l Assessment Ratings are based on both Number Head Data laboratory and field tests. of range available Discharge Rate Country pumps (meters) (months) , . From the field trial results, the puMp s .. ~~is clearly capable of achieving Cote d'lvoire 8 10-30 13 reasonable discharges when used. X- - 8 ' @with the right rhythm. It eams an -- FS.4wa t Badequateo (o) rating for lifts of 12, The basic design concept of the Abi-ASM 25 and 45 meters, but is below t pump has been to combine the positive minimumfora7miift. features of the Abi-MN and Vergnet ThEase o guMaintenance pumps. The Vergnet below-ground compo- The above ground components of nents are easy to install and extract and the Abi-ASM are easily maitained have good corrosion resistance. The lever The pump's discharge rate ranged by village caretakers, but the need operation of the Abi is generally preferred from 0.5 to 1.0 cu m/h, which was judged for skilled mechanics to dismantle to the foot-operated Vergnet by West to be adequate by most users. There is a the pumping element means that African users. notable difference between discharges the pump is rated 'unsuitable' (-) The ASM pump is still being measured in the field and those in the for Level A maintenance. Absence developed and improvements are needed laboratory. Discharge depends not only on of rods and rising mains earns the in the pumpstand design (bearings, the number of strokes per minute, but also pump a "good' (oo) rating for Level handle, piston/cylinder assembly). Imp- on the rhythm applied. Villagers operate B maintenanceatallpumpinglifts. rovements are also being sought in the the ASM at 20-35 strokes per minute at 50- Reliability diaphragm, to bring greater reliability and 75% of full stroke. The measured Field evidence of breakdowns and lower prices. discharge rates at 10, 20, 30 and 40 repair interventions earns the pump In Cote d'Ivoire, the pump has strokes per minute were respectively 3.2, a oo rating for reliability at a daily proved easy to install, requiring no heavy 8.5, 15.8, and 26 liters per minute at lifts output of 1.5 m3/d, o for 4m3/d at 7, equipment or special tools. between 1 Om and 20m. 12 and 25m lifts and - for 8m3Jd Maintenance too is quick and easy. No problems were encountered with andfor4m3/dat45m. The seals of the primary cylinder plunger corrosion, and the pump does not suffer Corrosion Resistance had to be replaced at intervals of about six trom abrasion. However, sand, silt or clay Below ground components of the months and the plastic fulcrum bearings at in the water do enter the diaphragm and pump' are made from corrosion asimilarfrequency. were responsible for ruptures in several resistant materials. Though some The diaphragm proved generally cases. corrosion was experienced with reliable, though when failure did occur it Users found the ASM's pumping earlier models, and the pumpstand, was necessary to replace it, at a cost of action quite acceptable, and the pump has primary drive piston rod and about US$ 200. high VLOM potential. diaphragm end caps are slightly vulnerable to corrosion, the pump now eams aoo rating. Abrasion Resistance The ASM pump is little affected by abrasion, as the pumping element has no seals. However, the diaphragm can rupture if sand or silt fills the element. The rating is therefore reduced to o. Manufacturing Needs This is a hybrid pump. The below ground components require special skills, but the pumpstand is suitable for manufacture in countries with foundry, fabrication and machining skills. Ratings for manufacturing environments 1,2 and 3 are therefore -, o and o respectively. PUMP 01 99 Kenya Laboratory Tests THE AFRIDEV PUMP HAS NOT BEEN TESTED IN THE CATR LABORATORY General Description development for lower lifts. The different of a small grappling device at the end of a The Afridev is a pump design developed handles mean that the same 50mm length of rope grips the footvalve to during the course of the Project with sup- diameter long-stroke cylinder can be used remove it for maintenance. port from donors, research organizations for all lifts (see Box 4.6 in Chapter 4). This fishing tool and a forged socket and private companies. Available in the Handle bearings are twin bushes of spanner are the only tools required for public domain, the design has aimed to proprietary plastics which snap together. installation and maintenance. demonstrate the VLOM concepts of Rising main is 63mm OD solvent Manufacture easy, low-cost maintenance and suitab- welded uPVC pipe suspended from the Though "modern" materials are used in the ility for manufacture in developing pumpstand using a compressed rubber Afridev, all components can be locally countries. cone. Standard pumprods are 10mm manufactured in Kenya, with the excep- The present design, which began galvanized mild steel with special hooked tion of the stainless steel cylinder liners limited production in Kenya towards the joints which eliminate threads and need no which are imported. end of 1985, is being modified further as a tools for assembly or dismantling. Stain- result of field experiences. Production of less steel pumprods are available at extra Suppliers the pumphead has also started in small cost for corrosive groundwater. The Afridev design is available in the numbers in Malawi, as a second gene- The standard 50mm cylinder is a long public domain. Information on individual ration of its forerunner the Maldev (Pump stainless steel tube sleeved into uPVC manufacturers is available from The 14). pipe. Plunger and footvalve are identical Regional Project Officer, Rural Water The Afridev pumpstand is an all-steel components comprising two plastic mol- Supply Handpumps Project, The World fabrication consisting largely of stock dings permanently spin-welded together Bank, PO Box 30577, Nairobi, Kenya. sections, and involves a minimum of close- (prototypes in the field were machined). A tolerance machining. The T-bar handle molded rubber valve bobbin snaps into the Indicative prices - Targets comes in two versions: a 3:1 mechanical valve housing by hand. The plunger seal is advantage for 10-30 meters lift; and a also a snap fitting, which can be installed Complete pumpto 4.5:1 mechanical advantage for 30-45m by hand and removed with the help of a 30 meters US$450 lift. A direct action version is under household knife. A fishing tool, consisting Spares pack US$12 100 PUMP 02 Afridev Field Trials Assessment Test conditions _________________________.__________ Field testing has been carried out Number Head Data _1t'W'~;_ on pre-production models of the of range available Afridev. Design moditicalions are Country p up mtr)(onh)_~-being made continuously, most Country pumps (meters) (months) l - recently to overcome problems Kenya 37 10-49 8 ~~~~~~~~~~~~~ - ~identified with bearing housi'ng Malai 37 10-49 1 2 3 corrosion and hooked pumprod Malawi 3 10-25 12 manutacture. The ratings retlect field trial performance so far, but As the Afridev design has developed, the limited nature of these trials different prototypes have been tested damage to the bearings. means that the ratings are nol during field trials in Kenya and Malawi, Users like the Afridev. The variable well substantialed at this stage though the progressive nature of the handle mechanical advantage maintains a Discharge Rate design means that the monitoring time for high discharge with easy operation over a The variable handle mechanical newly developed components is neces- range from 10 to 50 meters. Corrosion is advantage ensures a high dis- sarily restricted. not a problem, if stainless steel rods are charge for heads from 10 to 50m, An important aspect of the design used when water is aggressive. Nitrile out the -good" (oo) rating reduces has been the extensive research and rubber seals in the polished stainless to "adequate' (o) for 7m lifts, specialist advice on plastic components, steel cylinder lining give abrasion resis- where even the shortest practical particularly bearings. tance, which is further improved by the handle could not compete with Developments have concentrated on use of a large diameter suction pipe. This discharges from direct action simplification of maintenance and meas- minimizes sand ingress by reducing water pumps (a direct action version of ures to maximize local manufacturing velocities at the cylinder intake. the Afridev is being developed). potential. The hooked connections on the Ease of Maintenance Installation is simple; even at depths pumprods have proved successful, enab- The Afridev is a VLOM pump, and of 45 meters, there is no need for lifting ling two people to remove and replace a trials have confirmed its easy equipment. Two skilled people can comp- plunger and footvalve from a depth of 30m maitenance, justiaying the oo lete installation in about two hours (mainly in about 30 minutes without the need for lif- rating at all depths . r aii mainlen taken up in making the solvent-cement ting tackle or special tools. Some pumprod Reliabnlity joints in the rising mains). breakages have occurred, and these have The combination of simpte repairs In Kenya, the Afridevs were installed been attributed to shortcomings in the and low frequency of breakdowns on wells with pumping heads of 10-50 production of the hooked connections. earns Ihe pump a oo rating for meters, averaging 25-30 meters. These The push-fit bearings also make village most operating conditions, redu- arduous test conditions led to very few maintenance very easy. cing to o for lifts of 45m or a daily breakdowns. Some early prototype plastic Overall, the Afridev design is now outputof8m3/d. bearings seized due to poor dimensioning, demonstrating that deepwell handpumps Corrosion Resistance but since the present bearings were can be maintained by villagers, effectively All downhole components are installed at the beginning of 1986, there and economically, and that local manufac- corrosion resistant nt stainless has been little wear, though corrosion of ture can produce reliable pumps at an steel pumprods are selected). bearing housings has resulted in some affordable cost. However, corrosion of the pump- head bearing housing reduces the CAUSES OF ESSENTIAL INTERVENTIONS rating to o Abrasion Resistance 2- -25 -3 The nitrile seal in the polished 1.8 stainless steel cylinder lining In 1.6 -2 2.5 handles sand-laden water reason- 1o t.4 2 ably well, earning the pump a o 1 t; -2 o tatingof adequate'(o). § 1t2- 0 -t.S9 EManufacturing Needs o t - 1.5 The Afridev uses a number of El o.s 1 - -1 u M modem materials, the majority of a:6 - C -t twhich could be reliably processed C. 0.4 0.5 ain most developing countries. The if 0.4 M M -0.5 X-0.5 t need to import stainless steel 0-2] - - .cylinder linings and the quality 0 oT Ho control needed in plastics manu- TOTAL HD F RH PR RM PS PE FrV OT facture reduce the oo rating for PART REPLACED Categories 2 and 3 to o for HD-Hnndle RH-Rod hanger RM-Ris.ng main PE-Pump,ng ierment Category 1 countries. F-Fulcrum PR-Pump rod PS-P,ston seal FV-Foot vaive OT-Other PUMP 02 101 Laboratory Tests The AID Derivative manufactured in Sri Lanka has not been tested in the CATR Laboratory. This evaluation is related to the testing of pumps based on the same design manufactured in Honduras (the Funymaq) and Indonesia (the Sumber Banyu). The pumps were tested in 1983/84 and separate reports are included in Handpumps Project Report No. 3. Performance data (typical values) Head (meters) 7 25 45 $? Pump SB FM SB FM SB FM Pumping rate (cycles-min) 40 38 30 29 30 30 Volume,:min (liters) 34 27 25 20 24 21 Input (watts) 67 85 145 134 229 230 Mechanical effidency (%) 58 35 69 61 76 66 Maximum handle force (kg-f) 10 12 30 30 45 50 Footvalve leakage (milmin) NS NS 0.4 NS 2.4 NS P.umphud n,y my&ro, *SB = Sumber Banyu:. 78mm cylinder, Fl = Funymaq, 70mm cylhnder: NS = No significant leakage. General Description Evaluation the first 1000 hours, and the head was Though the basic design of the two pumps reduced to 30 meters for the remainder of This is a deepwell version of a pump is the same, the Funymaq performed much the tests. derived from a basic design developed by better in the endurance tests than the Pumprod failures continued to occur, the Battelle Memorial Institute and Georgia Sumber Banyu. It would therefore be including two failures of the plunger rod Institute of Technology on behalf of unwise to draw general conclusions about when the footvalve leather rotted away USAID. The pumpstand consists of a cast all AID Derivatives on the basis of these and allowed the cast iron weight to foul the iron drive head assembly and cast iron tests, though they do indicate pointers to plunger. At the end of the test, the cyl- base joined by a steel tube. The fulcrum be taken into consideration when evalu- inder end caps were heavily rusted, the stand is pinned to the pumpstand below atingthepumps. plunger and cupseals were still in good and the handle above, so that the fulcrum For example, both pumps demand a condition and the cylinder bore was pol- moves in an arc as the handle is operated. substantial complement of tools and equip- ished but otherwise showing few signs of The cylinder is conventional but uses ment for installation and mainte- wear. All other parts had been replaced at uPVC tube instead of brass.. The plunger nance and there was difficulty in some stage. is fitted with two leather cupseals and assembling the pumps from the compo- The Funymaq was tested at 30 there are two footvalves - one fitted to an nents supplied. In the case of the Sumber meters simulated head from the start and extension pipe below the cylinder. Banyu, components of the two sample performed very much better than the pumps were not interchangeable, and the Sumber Banyu. Only one failure occurred Manufacture spares supplied did not fit either pump. during the 4000 hours, when the leather Basic skills in foundry work, machining The Funymaq pump tops did not fit the footvalve broke away and caused severe and leather crafting are needed to manu- bodies (holes were drilled in the wrong damage to the plunger and the cylinder facture the pump and careful quality positions) and the handles were stiff to bore. There was considerable wear in the control is needed to ensure interchange- operate. Clearly, good quality control is handle bearings and guide blocks by the ability of parts. needed if pumps are to be serviceable. end of the 4000 hours, though they. The design is such that frequent remained serviceable. The Funymaq was Suppliers lubrication of the handle and fulcrum link badly corroded at the end of the test. The field test pumps were supplied by pivots is needed for satisfactory pump The Sumber Banyu base casting Diason Pumps Ltd, 112 Isipathana operation. Below ground maintenance inv- broke at 400 Joules in the impact test Mawatha, Colombo 5, Sri Lanka. olves removal of the complete assembly but the heavier casting of the Funymaq The laboratory tests were carried out and therefore needs heavy lifting equip- survived without damage. on pumps from Honduras (the Funymaq) ment, and frequent attention is likely to be The overall conclusion of the and Indonesia (the Sumber Banyu). needed to the leather cupseals and foot- laboratory tests was that the AID design valves. has some shortcomings. In particular, the Prices - Not available Initially, the 4000 hour endurance second footvalve is redundant and can test on the Sumber Banyu was actually cause worse damage than would The AID Derivative pumps are specifically conducted at 40 cycles per minute with a occur without it. Good quality control is designed to be manufactured in the deve- simulated head of 45 meters. Rapid wear needed if the pump is to be used for loping country in which they will be used. of linkages in the pumpstand, broken rods community water supply, and this was not Local prices should be obtained. and worn footvalves led to five failures in achieved on the pumps tested. 102 PUMP 03 AID Derivative (Deepwell) Field Trials Test conditions __________________________________ ~~~~~Because all AID Deepwell field Number Head Data trial pumps were installed in Of range available * ,$* ' t|j = shallow wells, the laboratory tests Country pumps (meters) (months) have been especially important in rating this pump. Sri Lanka 9 2.6*-5.2 1 Discharge Rate The pump delivers a high discharge for moderate effort at *Averagehead shallow lifts, and earns a "good' In the Sri Lankan field trials, the deepwell 5"^3f (oo) rating for lifts of 7 and 12 pumps operated at only small pumping lifts meters. The high handle force and with comparatively low outputs. The needed at higher heads reduces field trials therefore yield little evidence of the rating to "adequate" (o) at 25 the pump's likely performance in high lift check valves remained in good condition and 45 meters. applications. and there were few signs of wear on the Ease of Maintenance No instruction manual was supplied cylinders. Crosshead guides and blocks The need for lifting gear and with the pumps. Skilled workers are were worn but still serviceable and little special tools means that the needed for installation and they must be wear occurred on the fulcrum and pump is rated "unsuitable' (-) for equipped with tools and lifting equipment. rodhanger pins, which were well lubricated Level A maintenance. At 7m and On average, it took four workers about two during the trials. 12m, area mechanics can readily hours to install each pump. A concrete The pumping action and relatively carry out maintenance, earning a pedestal is desirable, to lift the operator to high delivery (24 liters per minute at 30 oo rating for Level B, but this a comfortable position. strokes per minute) were popular with the drops to o at 25m and 45m, where The exposed drive head means that users, and the pumps proved well suited lifting gear becomes essential. frequent lubrication is needed of the to this comparatively light duty. It was Reliability pumphead moving parts (at least once a clear however that maintenance commit- Laboratory tests showed that the month). The whole pump assembly has to ments will be quite high and call for AID Deepwell pump would need be removed for any repair to the plunger or significant resources in terms of excessive maintenance for valve assembly, and this means that a manpower and equipment. anything other than low lift and pump mechanic and two trained workers Laboratory problems over the low output applications. It is must be available with special tools and interchangeability of components were not therefore rated - for lifts higher skills. Great care is needed in handling the encountered in the field trials on Sri than 12 meters and for high cast iron parts. A new gasket is needed Lankan manufactured pumps. output applications at all lifts. each time that the pumpstand is removed, In concluding that the pump is Corrosion Resistance and care is needed when dismantling the adequate for very low lifts and relatively Heavy corrosion occurred in the threaded cylinder cap from the uPVC light use, it must be recognized that a laboratory tests and some rusting cylinder. suction version of the pump (Pump No 34) was apparent in the field trials. All test pumps performed without is available for lifts up to 7 meters, and The rating is therefore -. major failure, but leather cupseals were has the advantage that the cylinder does Abrasion Resistance replaced on three pumps. Plungers and not have to be lifted outfor maintenance. Leather cupseals are known to be a problem when sand is present in the water, and the pump is CAUSES OF ESSE"AL INTERVENTIONS ~~therefore rated - for abrasion * CAUSES OF ESSENTIAL INTERVENTIONS resistance. 1- 0.5 -10 Manufacturing Needs 0.9 8 Although intended for o.08 0.4 -8 manufacture in developing 0.7 - tv countries, the AID Deepwell C'0.67. -0catn ° o.7 w 2 v ~~~~~~~~~~~~~~~~needs careful quality control of i 0.6 - * 0.3 El -6 Ucasting and machining. It 0.5- therefore rates - for 0.4E 0.2 e 4 manufacturing environment 1 (low industrial development), but oo C 0.30 forenvironments2and3. ~.0.2- 0.1 2 0.1- 0- 0.0 10 TOTALHD F RH PR RV PS Pi FV OT PART REPLACED HD-Handlo RH-Rod hanger RM-R,.ing main PE-Pumping element F-Fulcrum PR-Pump rod PS-Piston seal FV-Foot valve OT-Other PUMP 03 103 Zambia Laboratory Tests Tc, h.ndk Date tested: 1986 Reported: Report notyet published Performance data (typical values) Head (melers) 7 25 45 Pumping rate cyclesimin) 43 40 40 -Z 15=1 Volume-min (lIlers) 12 11 11 Input(watts) 29 71 111 Mechanical efficiency (I.) 49 63 71 Maximum handle force (kg-f) 6 15 26 Footvalve leakage (ml min) No signiticant leakage Evaluation due to sand contamination. A new piston, The two test pumps were securely packed machined from uPVC and with a molded in a wooden case. Bearings in one handle rubber seal, was fitted, along with a Socla assembly were in poor condition, possibly footvalve. In this form, the pump as a result of damage during assembly. completed the remainder of the endurance Otherwise, both pumps were received in test. Both piston and footvalve were in good condition. good working order at the final inspection. Comprehensive and helpful instruc- Following these tests, the manufac- General Description tions were supplied in English. Instal- turer has adopted a piston design similar e ation is relatively easy, with no need for to that introduced in the laboratory, and The Bestobell Is a conventional lever- lifting tackle, provided that uPVC rising intends to use the same components in manufacteepw inforce pump, designed and main is used (the pump can also be used the footvalve. The Socla valve will be avail- manufactured in Zambia. The pumpstand with galvanized steel rising main). able as an alternative. and T-shaped handle are fabricated from Maintenance is also straight- Corrosion was detected inside the mild steel. Handle bearings are ball races. forward, as the plunger can be withdrawn pumpstand and on the center spindle of A single spanner fits all the fastenings in without removing the rising main (though the original piston, which was not stain- the pumpstand. The pump is designed to the whole below-ground assembly must be less steel. use uPVC rising main. With 2 inch rising removed to service the footvalve. One In the impact tests, the baseplate main, the piston may be withdrawn without spanner fits all the pumpstand fastenings, was distorted by a heavy impact on the removing the main. Footvalve mainte- but care will be needed when new handle pumpstand, and a small crack appeared at nance does require extraction of the full bearings have to befitted. the weld. The handle fulcrum bracket below ground assembly. Pumprods are The 4000 hour endurance test broke during the handle shock test. 12mm steel with threaded connectors. was carried out at 40 cycles per minute, The pump was generally well rec- The cylinder is heavy duty uPVC with a simulated head of 45 meters. At the eived by users, who liked the T-handle pipe. Early models used leather ring seals, beginning of the test, the pump was fitted and the relatively low efforts required. but the current design has a molded with a piston of the early design, with However, some adults considered that the rubber seal fitted to the uPVC piston body. leather ring seals. There were no failures rate of delivery was rather low. Piston components are also used in the in the first 2000 hours, when pumping The overall conclusion of the footvalve, or a Socla valve is supplied as clean water. However, when the cylinder laboratory tests was that the Bestobell an option. was dismantled for inspection, the piston was a design with good potential for body was found to have broken between manufacture, maintenance and repair in -Manufacture the two leather seals. developing countries, but requiring some Above and below ground components are The piston was replaced, but failed additional development before it could be suitable for manufacture in many devel- soon after the start of the second phase consideredforlargescaleapplication. oping countries, with care needed in alig- of the test, when sand and Kieselguhr had The manufacturer has been ning and assembling handle bearings and been added to the water. Sand embedded hampered by the limited availability of in cutting threads in the cylinder barrel. in the leather seals had caused severe suitable materials in Zambia, but has Suppliers wear of the cylinder bore. The footvalve nevertheless demonstrated a receptive Bestobell Zambia Ltd, 875 Zambia Road, had also developed a serious leak, again and flexible attitude. PO Box 230003, Ndola, Zambia. Indicative prices - 1986 Per unit, excluding US$ 225 pumprod and rising main 104 PUMP 04 Bestobell Field Trials Assessment The Bestobell ratings are based on its performance in laboratory trials and on judgments of the Project staff using comparisons with pumps of similar design. - Discharge Rate Though ihe pump s easy to use, it is difficult to sustain a very high output. With acceptable work inputs, it scores an "adequate' (o) - . . b rating for all lifts. Ease of Maintenance Even at shallow settings. the pump is not suilable for main tenance by a village caretaker (Level A), though area mechanics THE BESTOBELL PUMP HAS NOT BEEN TESTED IN will find it easy to service. Lifting gear is likely to be needed for lifts THE PROJECT FIELD TRIALS of 25 meters or more. The pump therefore eams a "good" (oo) rating for Level B maintenance at 7m and 12m. reducing to "adequate" (o) at 25m anri 45m. Reliability Replacement of ihe original piston with a new design improved the pump's performance in the laboratory trials. In its new form, reliability is rated as oo for an output of 1.5m3/d, and o for 4m3/d at lifts up to 25 meters. It is not considered suitable for a daily output of 8m3/d and with presently available data, it is considered prudent to rate it 'unsuitable" (-) for 4m3/d at a lift of 45m. Corrosion Resistance With stainless steel pumprods, and piston spindle, no corrosion of downhole components occurred in the laboratory trials. Spots of rust inside the pumpstand reduce the rating to o. Abrasion Resistance After replacement of the leather seals with molded rubber, a little abrasion occurred in the laboratory tests, but the pump remained in good working order. It therefore earns a o rating Manufacturing Needs Though the Bestobell has been designed for manufacture in a developing country, a degree of quality control is needed. This reduces the oo rating to o for manufacturing environment 1 (low level of industrial development). PUMP 04 105 United Kingdom Laboratorv Tests Date tested: 1979 Reported: O.D.A. Report 1981 Performance data (typical values) - 225 inch cylinder I S Head (meters) 7 25 45 Pumping rate (cyclesimin) 29 60 29 60 29 60 Volume, min (liters) 9.3 19 9 18 5 8.7 18 Input(watts) 31 64 63 130 89 183 Mechanical effioency (O.) 33 32 58 58 73 73 Maximumhandleforce(kg-f)15 25 18 20 10 15 Footvalve leakage (mt/min) Not significant 08W Note: The maximum handle force is very operator dependent and is higher when starting from rest. Evaluation satisfactory, and mechanical efficiencies A very heavy pump (185 kg in all for the up to 74% were recorded. pumpstand), which though complicated is The endurance test was General Description designed to have a long life. Its weight conducted at 40 cycles per minute with a The Climax is a rotary-drive reciprocating means that installation and mainte- simulated head of 45 meters. The Climax nance involve the use of heavy lifting proved very reliable. There were no break- force pump of long-standing design. The equipment. Though the optional extrac- downs during the 4000 hours of pumping pumpstand is predominantly cast iron and table cylinder avoids the need for rising and no significant wear of key compo- has a large counterbalanced flywheel main removal during maintenance, the nents. Some leakage through the pump- driving the pumprod via a crank and conn- pumpstand still has to be removed before stand inspection cover was easily rectified ecting rod. Twin flywheels are avaifable as the piston and valve can be extracted. The and did not recur. an option. Internal mechanical parts are crank case oil needs periodic replen- The high handle loads during starting splash lubricated from an oil bath. A ishment. and stopping did cause fatigue failure of moving pumprod seal in a cylinder below The design of the pump proved the handle at the threaded connection with the crank provides a double-acting effect popular with most users. Use of a very theflywheel,wheremaximumbendingload tosmooththeflowof water. heavy flywheel makes the pump smooth occurs. Repeat tests on a fatigue testing A range of cylinder diameters is avail- and easy to operate, even on deep wells, machine revealed that loads as low as able to suit different depths. The cylinder though the starting and stopping handle 20kg-f could cause failure within a million is a brass tube with a gunmetal plunger load can be as high as 35kg-f. Also, the revolutions. fitted with two leather seals. An alternative continuing flywheel rotation after the user Use of a brass cylinder with galva- model is available with extractable piston has stopped pumping is a hazard to any nized rising main and pumprods causes and footvalve. Wooden pumprods are children who may stray near to the fast corrosion problems in acidic waters, and supplied with the extractable valve moving handle. The pumpstand design severe pitting occurred in both the pipe cylinder and galvanized steel rods with the makes it difficult to achieve a satisfactory and the rod near the cylinder when pum- non-extractable cylinder. sanitary seal, as it is relatively easy for ping water with a high dissolved oxygen contaminated water to seep under the content. The pumpstand withstood the Manufacture base and down inside the well casing. impact tests satisfactorily. Both pumpstand and cylinder require good There are many external fixings on In comparison with other deepwell iron and gunmetal foundry and machinery the pump, mainly nuts and bolts without pumps, the Climax's performance was skills with high quality control. locking washers, which are easy to liked by users. The flywheel action gives remove. The pump is not therefore resis- an even discharge from the spout, and Suppliers tanttovandalismorpilferage. most buckets could be filled without Wildon Engineering (Worcester) Ltd, White- Leathers supplied with the sample splashing, though the relatively low spout ladies Close, Little London, Worcester, pumps were too thick (5mm instead of (375mm) may mean that some containers WR1 1 PZ, UK. 4.2mm). When the pump was installed the would have to be tilted. operation was just satisfactory, but after a The overall conclusion of the Indicative prices - Jul 1985 few days the leathers swelled and jammed laboratory trials was that the Climax is a in the cylinder., well-made, easy to use and reliable pump, Single flywheel pump US$ 480 Second and third sets of leathers liked by users, but with some minor 50mm rising main (per meter) US$ 7.50 purchased from the manufacturer expe- problems with the handle and leathers Pumprodsandconnectors(m) US$3.10 rienced the same problem, so leathers needing to be overcome. Its heavy Non-extractable cylinder US$90 from a different source were substituted construction makes it unsuitable for Extractable cylinder US$ 105 and used in all the tests. These were village-level maintenance. 106 PUMP 05 Climax Field Trials Assessment In the absence of field trials, ratings for the Climax pump are based mainly on performance in the laboratory tests. W * / LI.tz Discharge Rate ,, _ i -- A range of cylinders to suit different lifts allows the Climax to i +,tz -.4iLf S#. t achieve "good' (oo) ratings for all pumping lifts. Ease of Maintenance The pump is difficult to service and requires a mobile mainte- nance team for installations at all depths. It is therefore rated unsuitable (-) for maintenance systems A and B. THE CLIMAX PUMP WAS NOT FIELD TESTED Reliability BY THE HANDPUMPS PROJECT The pump performed relatively well in the laboratory endurance test and achieves a oo rating for reliability for depths up to 25 meters and daily outputs up to 4m3/d. The rating reduces to o for an output of 8m3/d at all lifts and for 4m3/d at 45m lift, where the operating effort and wear of moving parts is greater. Corrosion Resistance Corrosion occurred in the laboratory, and the Climax's downhole components are not corrosion resistant. It is therefore rated unsuitable under this heading. Abrasion Resistance The pump survived without breakdown in the laboratory sand- pumping tests, but use of leather cupseals means a - rating for abrasion resistance. Manufacturing Needs The manufacturing facilities and skills required to make the Climax, and the degree of quality control needed, mean that it is unsuitable for manufacture in countries with low or moderate industrial development (cate- gories 1 and 2). However, as specialist facilities are not required, the pump is rated oo for manufacture under Category 3 (high level industrial deve- lopment). PUMP 05 107 Japan Laboratory Tests Date tested: 1982 Reported: Handpumps Project Report No. 3 Performance data (typical values) - 63mm dia. cylinder Head (meters) 7 25 45 Pumping arc* F- P. F F Pumping rate (cycles/min) 40 40 40 40 Volumelmin (liters) 22 11 22 21 Input (watts) 80 35 168 244 Mechanical efficiency (%) 31 34 52 63 Maximumhandleforce(kg-f) 8 8 18 30 Foot valve leakage (ml/min) No significant leakage A I J * At 7 meters head, tests were conducted both with the full 1780 handle move- ment (F = Full) and with only the central 60° of movement utilized (P = Partial). Evaluation 1000 hours revealed that handle fulcrum [1-1] The two sample pumps were well packed joints were badly worn and there were and were received in good condition. signs of wear on the plunger valve. No installation instructions The three breakdowns occurred in General Description were supplied with the pumps and the second half of the tests. The final installation proved difficult, as the cyl- inspection revealed that the pumpstand, The Dragon pump is available either as a inder stroke length is virtually the same cylinder and plunger were generally in shallow-well suction pump or as a deepwell as the handle movement in the pumphead good condition, but the footvalve guide force pump. The pump tested was the and careful adjustment of pumprod length was badly worn and there was some wear deepwell configuration, as illustrated. The is needed to avoid damage during on the valve stem. The cylinder end caps pumpstand is principally cast iron, with a operation. A plinth is needed to provide were rusty, there was considerable discharge valve in the spout allowing adequate clearance under the pump corrosion on the plunger rod, and the either free discharge or delivery under spout. Lifting tackle is required for pump outlet diverter valve had rusted solid. pressure through a hose or pipe. The installation. The Dragon 2 failed the side impact tubular steel handle moves through an Maintenance demands are likely to test on the handle, which began to bend unusuallywidearc(178'). be high, involving regular lubrication and at the lowest impact energy (50 Joules). In the deepwell pump, the cast iron frequent repair or replacement of At 200 Joules, the base casting of the cylinder body and enamelled steel liner of pumpstand components. Below ground pumpstand broke. the shallow-well version is retained as a maintenance involves removal of the Many users found it difficult to pedestal. The pump needs a mounting complete assembly, which means that decide on the best operating action, plinth at least 300mm high, to provide ade- lifting tackle must be available. because of the very large handle quate clearance under the spout. The The 4000 hour endurance test movement. Those who attempted a full deepwell cylinder is conventional seam- was carried out at 40 strokes per minute stroke found the exaggerated body less 63mm brass tube with cast iron end with a simulated head of 45 meters. The movements uncomfortable. caps. The plunger has two leather cup- Dragon 2 failed three times during the The overall conclusion of the sealsandthefootvalvehasarubberseat. testing: once when the handle fork broke laboratory trials was that the Dragon 2 after wear had caused it to come in seems designed for family use, perhaps Manufacture contact with the fulcrum pin retaining serving up to 15 people, and is not suffi- Gunmetal and iron foundry work and basic screw; and twice as a result of breaks in ciently robust for community water machining are required and good quality the threaded section of pumprods. supply. It is inexpensive, but intensive control is needed to ensure correct func- After 1000 hours, the plunger had use will produce rapid wear in the moving tioning and interchangeability of parts. become difficult to remove because of parts of the pumpstand, and rod scale in the cylinder bore; the footvalve breakages are also likely. The diverter Suppliers guide and pumprod gland were worn; the valve is seen as an unnecessary compli- Kawamoto Pump Manufacturing Co, 11-39 spout would not swivel into the pressure cation for most applications. The arc of 4-chome, Ohsu, Naka-ku, Nagoya, delivery position; and there was some movement is too large, particularly as Japan. Similar pumps made in the Philip- corrosion of cylinder end caps and the there is little piston movement at each pines by Sea Commercial Inc (Jetmatic) plunger rod. Inspection after a further end of the handle movement. and Malanday Machining and Manufac- turing Corp (Sea Horse). Prices - Not available 108 PUMP 06 Dragon 2 Field Trials Assessment In the absence of field trials, ratings for the Dragon 2 pump are based mainly on performance in the laboratory tests. A suction version of the pump is available for lifts up to 7 meters, but these ratings are based on the deepwell version tested in the laboratory. Discharge Rate The Dragon 2 should be capable of comparatively high discharges j ¢ sAt over the full range of pumping lifts. However, the awkward ope- rating action reduces the rating to C-! 4; ,^, F"adequate' (o) in each table. S . \ o Ease of Maintenance 0 ni Though lifting tackle is not needed for shallow lifts (7 or 12 meters), the relative complexity of servicing makes it unsuitable for village-level maintenance (Sys- tem A) even at these lifts. Area mechanics would need assis- tance for servicing at depths of THE DRAGON 2 PUMP WAS NOT FIELD TESTED 25 meters or more so that the BY THE HANDPUMPS PROJECT ratings for Level B maintenance are 'good" (oQ) for lifts of 7m and 12m and "adequate" (o) for lifts of 25m and 45m. Reliability The laboratory tests showed that the Dragon is not well suited to intensive use, or to pumping lifts of 25 meters or more. For low lifts and light use, servicing needs would not be high and the pump is therefore rated oo at lifts of 7m and 1 2m for a daily output of 1.5m3/d, o at the same lifts for 4M3/d and - for 8m3/d. At 25m and 45m, the rating is-. Corrosion Resistance Significant corrosion was obser- ved in the laboratory tests, and the Dragon is not suitable for use with corrosive water. Abrasion Resistance Use of leather cupseals earns the pump a - rating for abrasion resistance. Manufacturing Needs The Dragon 2 is not suitable for manufacture in countries with a low level of industrial develop- ment (category 1) because of the need for foundry and machining skills. For categories 2 and 3, the ratings are o and oo respectively. PUMP 06 109 Belgium LaboratorV Tests THE TROPIC 7 PUMP WAS NOT TESTED IN THE CATR LABORATORY General Description A deepwell reciprocating pump operated by rotary action of disk flywheels fitted Manufacturer's performance data with handles. The heavy cast iron pump- stand is available with one or two Head (meters) 20 30 40 60 flywheels, and the pump is commonly Cylinderdiameter(mm) 90 75 60 50 operated by two people. The flywheels are Well casing diameter (mm) 150 100 90 90 weighted so that the handles are at the Pumping rate (cycles/min) 60 60 60 60 bottom when the pump is at rest, and this Volume/min (liters) 54 38 24 17 enables children to pump water by rocking Input (watts) 179 186 157 164 the handle to and fro without complete Maximum handle force (kg-f)* 14 13 13 13 rotation. The rotary action is transmitted to Force shown is for one operator. With two operators, forceperperson is halved. the reciprocating pumprods through a I crankshaft, connecting rod and inter- mediate piston rod running in guides, all enclosed in the pumpstand. A version the manufacturer to enable the Tropic 7 to Indicative prices - Feb 1985 (Tropic 3) is available in which the piston be driven by animal, diesel, or electric rod passes through a gland and the pump power. A sterilizer system is also Tropic 3 pumpstand US$ 980 can be used to raise water an extra 10 available. Cylinderassembly US$230 meters toastorage tank. The pump is sold with a 5-year Galvanized steel rising main The Tropic 7's pumprods below the warranty. per meter (in 3m lengths) US$7 intermediate piston rod in the pumpstand Alternative uPVC rising main are Oregon Pine timber, though stainless Manufacture first 15 meters US$140 steel rods are available as an option. The Tropic 7 includes a number of perextra5meters US$36 There is a guide (spacer) at each rod patented design features and its manufac- Timber pumprod and galva- connector. The cylinder is an open-topped ture involves several highly specialized nized connectors brass tube and has two leather cupseals processes, which call for a high level of per meter (in 5m lengths) US$4 and weighted rubber valves. Five cylinder skill and stringent quality controls. Alternative 12mm stainless diameters are available, to suit different Manufacture in a developing country steel pumprod water depths. The piston and footvalve could therefore only be undertaken in per meter (in 3m lengths) US$10 can be extracted without lifting out the collaboration with the Belgian manufac- rising main. turer and then only in a country with an Discount: The rising main can be galvanized advanced industrial base and ready 50 units less 10% steel or uPVC. When uPVC is used, a access to the necessary materials. 500 units less 20% patented system is provided whereby the bottom of the rising main is supported in a Suppliers FOBAntwerp tapered ring fitted to the well casing. Pompes Deplechin SA, Avenue de Adapting equipment is available from Maire 28, B-7500 Tournai, Belgium. 110 PUMP 07 Duba Tropic 7 Field Trials Assessment Test conditions Test______conditions ________________ Ratings are based on field trials in Number Head Data which pumping lifts ranged from 8 of range available a to 57 meters in predominantly of range available ~~~~~~~~~~~~~large diameter dug wells. Country pumps (meters) (months) . Discharge Rate Niger 32 8-57 19 s e s The Duba Tropic 7 has been _ _. designed for two-person oper- ation and achieves very high Average installation depth of the Niger discharges. It therefore earns a test pumps is 36 meters, and all but two _ good" (oo) rating for all pumping are on large diameter dug wells and lifts. located alongside India Mark II pumps. I a Ease of Maintenance Depending on the static water level, the _ 7 The pump is not suitable for cylinder diameter used is 60 or 75mm. village-level maintenance, but the The operating conditions differ from at 70 revolutions per minute were able to open-topped cylinder does make those anticipated by the manufacturer in pump 40 liters per minute from a depth of area-mechanic maintenance fea- two ways: on the dug wells, the pump 45 meters, whereas one man on the India sible for routine repairs. Ratings rising mains are not fixed to the well Mark II achieved 13 liters per minute at 50 for Maintenance systems A, B linings, which means that the rising main/ strokes per minute. During the dry sea- and C are therefore "unsuitable" pumprod assembly can move laterally son, Tropic 7 pumps with 75mm cylinders (-), "adequate" (o), and 00 much more than in a drilled well; and the were estimated to be achieving maximum respectively for all lifts. wells are dug only a short distance beyond daily outputs as high as 25m3. Reliability the water table, so that the bottom of the Though heavy lifting equipment is On the basis of the number of cylinder is generally only 0.5 to 1.0 meters needed for pump installation, the open-top interventions needed in the field above the sandy well bottom. cylinder allows most maintenance of down- trials, the Tropic 7 is rated - for a Frequent failures of cupseals and hole components to be carried out without daily output of 8m3/d at 25 meters valve seals can be attributed to sand special lifting tackle. lift and for 4m3/d at 45m lift. The drawn in by the Tropic's high delivery rate. In a field trial demonstration, a local rating is o for 4m3/d at 7m, 1 2m Pumprod breakages may not have occur- mechanic, assisted by four villagers and and 25m, and oo for 1.5m3/d at red in drilled wells, where lateral move- using only simple tools, was able to 7m and 12m. Ratings may well ments of the rising mains and pumprods extract the piston and footvalve from a have been better if the pump had are very limited. Heavy wear of the guide depth of 46 meters in 60 minutes and to been installed on drilled wells. rod bushing also required frequent inter- replace them in 40 minutes. Corrosion Resistance ventions, and this problem seems to be The Niger pumps were fitted with non- The standard version with mild aggravated by fine sand getting into the galvanized steel rising mains, and this led steel or galvanized rising mains is bushing. to corrosion problems in the trials. not corrosion resistant, though The high discharge achievable with As the timber pumprods offer corrosion resistant alternatives the Tropic 7 proved highly popular with corrosion resistance, it would seem are available as an option. users, and some villages asked for the prudent to use the optional uPVC rising Abrasion Resistance India Mark lIs to be replaced with Tropics. main wherever corrosion might be Use of leather cupseals means a Typically, two men operating the Tropic 7 anticipated. - rating for abrasion resistance. Manufacturing Needs CAUSES OF ESSENTIAL INTERVENTIONS The Duba Tropic 7 requires a high CAUSES OF ESSENTIAL INTERVENTIONS ~~level of manufacturing skill and 5- -5 sophisticated facilities. It is not 4.5- 7 therefore suitable for manufac- K 4- . -7 X ture in countries with low or -6 0 medium level industrial develop- s 385- t s ment, though for a category 3 § 3- _5 < -3 ° country (high level of industrial o 2.5- 4 development) the rating is oo. l 2X MThis would nevertheless require ffi 2- _ -3 = -2 X close collaboration with the 1.5- * 2 Belgian manufacturer, because of EL a * * 1ll X -1 ;;Epatented design features. TOTAL HO F RH PR RM PS PE FV OT NART REPLACED HO-Handle RH-Rod hanger RM-R..ing main PE-Pump,ng element F-Fulcrum PR-Pump rod PS-Piston seal FV-Foot valve OT-Other PUMP 07 111 Canada Laboratory Tests Date tested: 1984-85 Reported: World Bank Applied Technology Note No. 2 Performance data (typical values) - 2 inch dia. cylinder Head (meters) 7 25 45 Pumping rate (cycles/min) 40 40 40 Volume/min (liters) 11.7 11.7 11.6 Input (watts) 25 66 100 Mechanical efficiency (%) 54 72 90 F<"- Maximum handle force (kg-f) 4 10 14 Footvalve leakage (ml/min) One sample leaked badly Other sample no significant leakage Note: The volume flow was almost unchanged after the 4000 hour endurance test, but the effort had increased, lowering the efficiency by 9% at 45 meters and 30%0 at 7meters lift. Evaluation At the end of the endurance test, the The two sample pumps were well packed plunger rod was found to be severely {i _ and arrived undamaged. However, one corroded immediately above the plun- footvalve body was subsequently found to ger, and some handle bearings were loose leak, one plunger rod had been poorly in their housings. The pumprod guide threaded, and the handle pivot bearings bushes were in good condition, as l_____________ werenottightinonesample. were the plunger and footvalve. The Installation instructions were cylinder bore was slightly scratched but supplied in English and contained cutaway showed little sign of wear. General Description drawings of the pumpstand and cylinder The pumpstand was bent by some of assembly. More illustration of installation the heavier loads applied in the impact The GSW is a conventional reciprocating procedures and less text would be more tests. The pump remained serviceable, pump with a cast iron pumpstand suppor- useful fordeveloping countries. but distortion of the pumprods could be ted on a fabricated steel pedestal. The Lifting tackle is essential for instal- expected to accelerate wear of the guide intermediate pumprod slides in a guide lation and skills are needed to ensure bushes. Two handles broke early in the bush and gland, and the handle is att- proper sealing of the well top. The pump- shock test and a non-standard solid steel ached via a swinging link. All handle rod may need cutting and rethreading. handle was fitted to enable tests to be bearings are sealed ball races. Maintenance of the pumpstand completed. The conventional drawn brass tube demands special skills and tools, and Users found the pump comfortable, cylinder has a gunmetal plunger and foot- replacement of worn or damaged parts will and particularly easy to operate. valve, the plunger being fitted with two only be possible if manufacturing quality As a result of the testing, CATR leather cupseals. A 2 inch diameter cyl- control has been high. Servicing of below- suggested a number of design improve- inder has replaced the 2.5 inch cylinder ground components involves extraction of ments, including strengthening of the used on earlier models. the complete assembly, including rising handle and modifications to the fixing main, so that lifting tackle is essential for arrangements, strengthening of the Manufacture deepwell installations. pedestal, changes to the bearing arrange- Very good quality control is needed to The 4000 hour endurance test ments, and a modified spout design to ensure correct functioning of the was carried out at 40 cycles per minute, prevent it being readily blocked with the pumphead and interchangeability of spare with a simulated head of 45 meters. The user's hand (a contamination risk). parts. Manufacture in a developing coun- GSW completed the test without failure. In other respects, the overall try would only be possible if good quality The pumpstand was noisy during the first conclusion of the laboratory trials was iron foundry work and accurate machining 1000 hours, when movement of the that the GSW was a reliable pump, easy to could be guaranteed bearings in their housings allowed some operate and efficient, but likely to suffer metal-to-metal contact between the from corrosion in aggressive waters and Suppliers handle and the fulcrum link. The noise not suitable for manufacture in most GSW Water Products Company, 599 Hill subsided after 1000 hours. developing countries. Street West, Fergus, Ontario, Canada. Indicative prices - Apr 1985 Pump and cylinder US$ 340 Pumprod per meter US$ 1.65 Rising main per meter US$ 9.00 112 PUMP 08 GSW Field Trials Assessment In the absence of field trials, ratings for the GSW are based on performance in laboratory rests. Discharge Rate The GSW produces a good (too) discharge for the deeper lifts (25 and 45 meters), but is only rated "adequate' (o) when compared wrth high discharge pumps avall able for lower lifts (7 and 12 =- ~~~~~meters). ,- Ease of Maintenance The need for special tools and An earlier model of the GSW, which has skills to service the pumpstand since been modified. makes The GSW unsuitable for village-level maintenance (Sys- tem A) at any depth. At 7 and 12 meters, an area mechanic could carry out most maintenance ope- rations, earning the pump a oo rating at these depths for System THE GSW PUMP WAS NOT FIELD TESTED B maintenance. However, the BY THE HANDPUMPS PROJECT need for lifting gear reduces the rating to o at 25m and 45m. Reliability More difficult maintenance at deeper settings, reduces the GSW's reliability ratings from oo at 7m and 12m lift and discharges up to 4m3/d, to o for 4m3/d at 25m itt (the same as the 8m3/d rating for the lower lifts), and the pump is rated unsuit3ble' (-) for 45m lifts or for a daily output of 8md' a al 25m lift. Corrosion Resistance Severe corrosion occurred in the laboratory tests, and the pump is not considered suitable for use with corrosive water. Abrasion Resistance Though there was little sign of abrasion damage during the laboratory tests, the use of lealher cupseals earns the pump a - rating for abrasion resis- tance. Manufacturing Needs Good quality control is essenlial in manufacture of tr,e GSW, which is not theretore SulITaDle for manu- taclure in countries wilh low indus trial development (category 1). No specialized processes are invol- ved, so ihe pump is rated o for manufacture in a category 2 environment (medium industrial development) and oo for category 3 (high level of industrial develop- ment). PUMP08 113 India, Mali Laboratorv Tests __/Ch-m ---glm hmA Date tested: India Mark II - 1979; India-Mali - 1986 Reported: ODA Report 1981 Performance data (typical values) - 63.5mm cylinder \_ P~on Head (meters) ' 7 25 45 _ P.-ton Pumping rate (cycles/min) 40 40 40 Volume/min (liters) 12 12 12 Input (watts) 47 92 140 Mechancal eticiency %i.o 30 55 65 Maximum handle force (kg-f) 13 20 30 Footvalve leakage (ml/min) No significant leakage / Foot valv, Evaluation The test pumps from both India and Mali the joint between the plunger and were securely packed in wooden crates pumprod. The cylinder bores were poli- and arrived in good condition. The Mali shed, but only lightly scored, and the cup- pumps did not have brass-lined cylinders, seals were still serviceable. The footvalve General Description as specified in IS 9301, but instead had seals were worn, but also still serviceable. stainless steel cylinders. Both sets of Impact tests on the handle and The India Mark II is a lever-action deepwell pumps had minor defects: fixings for the pumpstand caused no damage, and the pump developed with UNICEF support and chain inside the pumpstand were incom- pump completed the handle shock test now the subject of Indian Standard IS patible on the Indian pumps; in one Mali without failure. 9301 (1984). The pump is widely used in pump the handle pivot had been Most users found the required India and is increasingly being installed in misalligned during assembly, and one efforts relatively easy to apply, though othercountries. handle had been incorrectly machined. adults commented that a longer stroke The pumpstand and handle are galva- No instructions for installation and would make the pump more comfortable to nized steel, and the pump is distinguished maintenance were supplied, but a compre- use and some children tended to bang the by the chain and quadrant link between hensive manual is now available from most handle against the stops. the handle and pumprod, which depends manufacturers. Installation needs well- The overall conclusion of the on a gravity return to effect the down- developed skills, lifting tackle, and a laboratory tests was that the India Mark II stroke. Ball races are used for the handle comprehensive tool kit, ruling out village- is a strong, generously proportioned bearings. The steel pedestal is concreted level maintenance. design, of which examples manufactured The below-ground assembly is con- The 4000 hour endurance test in both India and Mali proved to be robust ventional with a brass-lined cast iron was carried out at 40 cycles per minute and reliable. cylinder and a footvalve incorporated in with a simulated head of 35 meters for the Its potential for widespread applic- the lower of the gunmetal endcaps. The India pump and 45m for the Mali pump. ation in village water supplies is limited by standard pump has galvanized steel rising Both pumps completed the test with no serious drawbacks in terms of manufac- main. It is recommended that the pump failures. In the final inspections, the turing and maintenance. It is suitable for has a 24 meter minimum setting for gravity handle pivot bearings were found to be in manufacture to a consistently high quality return with the standard rods. Heavier rods good condition, but the pumprod guides only in countries with moderately well are available for shallower settings. were worn. The Mali pump also had wear of developed industry and engineering skills. Manufacture the chain and of the pumpstand where the Maintenance also demands a high degree The pump is made in India and Mali and handle had rubbed against it. of skill, and lifting tackle will be required calls for skills in steel fabrication and Below ground, both pumps suffered a unless plastic rising main can be used. foundry work with good quality control. good deal of corrosion, particularly at Limited pumphead manufacture is carried out in Kenya. Suppliers A list of manufacturers making the pump in India is available from UNICEF, 73 Lodi Estate, New Delhi 11003, India. Emama-Sikasso, BP 68 Sikasso, Mali. Indicative prices - Feb 1985 * The modified version of the India Mark II, which has extractable downhole components, is desc- Per unit for 35m depth US$295 ribed later (Pump 10). 114 PUMP 09 India Mark 11 (standard) Field Trials Assessment Test conditions t|^g A2- -! The raTings for the India Mark II Number Head Data - pump are based on widerang,ng of range available ~ ~ ~ ~ ~~~~~ and consistent data from field of range available - Country pumps (meters) (months) - tnals and laboratory tests. India 50 17-44 21 Xi ; - For deep lifts, the pump achieves India 50 17-44 21 Sri Lankat 10 2-9 22 = ziii ! comparatively high discharges, BurkiLnkat 1ao0 10-26 3322~- ' sconng a 'good" (00) rating for Burkina Faso30 10-26 33 depths of 25 and 45 meters. Ghana 220 4-65 34 _ ~ . ._ However, the pump cannot com Niger 9 15-58 15 pele wilh the high ouiputs of Sudan 75 12-38 24 Sudan, trained village repairers were direct action pumps at lower lifts, Malawi 24 7-25 40 successful in only 10 cases, could have and the rating drops to 'adequate' Kenya 15 16-31 17 repaired another 9 if the parts had been (o)forliftsof7mand12m. Tanzania 22 1-25 9 available, failed in 15 cases, and made no Ease of Maintenance Philippines 15 6-40 20 attempt in the remaining 16. The skills and tools needed to China 34 9-26 10 The pump also proved difficult for service the India Mark il preclude mechanics in West Africa to install and village-level maintenance. and tLow-lift version maintain, though again the durability of the the pump is rated unsuitable (-) pump was very good, and it was well liked under System A. Area mechanics As befits a pump which is so widely used by users - except for Niger, where there can service the pump at shallower in India and elsewhere, the India Mark II was a strong preference for the high dis- lifts (bearing in mind that the has featured in a great many of the field chargefromthe DubaTropic7i(Pump 07). standard pump has a minimum trials, and has tended to be the standard Bearing failures accounted for a cylinder setting of 24 meters to againstwhichotherpumpsarejudged. number of breakdowns, but the India Mark achieve gravity return), but In India, where a million or more Mark II's main problem in West Africa came for beyondJ 25m lifts, the oo rating for lIs are in use throughout the country, the corrosion of below-ground components. System B reduces to o, as tests were carried out in unlined hard rock The galvanized steel pumprods and rising assistance may be needed from a wells with cylinder settings averaging 36 mains fell victim to the region's corrosive mobile team. meters. The pump is well accepted in the water, to the extent that some 65% of Reliability country and can be satisfactorily main- breakdowns in the southern Ghana field The India Mark il is durable, but tained by experienced area mechanics, trial could be put down to corrosion. the difficulty of maintenance at though this is not the case in other Corrosion also featured indirectly in depth reduces the oo rating for countries, where mobile teams with lifting the Sri Lanka trials, where the shallow reliability !o a ai 25m lift and 4m-4.d equipment are almost essential. wells were fitted with a low-lift version of output, and the pump rates - for Chain lubrication and tightening of the India Mark II. The pumps used six 8m3/d at the same lift and for fasteners accounted for most of the meters of 25mm diameter pumprods in 4m3/d at 45m. routine maintenance operations, and place of the standard 24 meters of 12mm Corrosion Resistance plunger seal replacement was the most rods needed to achieve gravity return. Use of means at- ratind common repair needed in the India trials, Complaints from users about the taste of Arsing mainsmeansa-raing. accounting for 78% of the essential inter- the water were almost certainly attribu- Leather cupseals are known to ventions. Interestingly, one manufacturer table to corrosion by-products. give problems in sand-laden has recently replaced the standard The test pumps were fitted with open water, and resultin a-rating. leather cupseals with nitrile rubber cup- top cylinders and 3-inch galvanized steel Manufacturing Needs seals, which are more abrasion resistant rising main (three were later fitted with The India Mark II is manufactured and do not swell (see Pump 10). PVC rising mains). Though seal in India and Mali. The degree of The experience of India's area replacement was easier, serviceability quality control needed to ensure mechanics means that repairs are gene- was limited by the need to remove the reliable operation makes the rally carried out promptly and econo- large diameter rising main to gain access pump unsuitable for manufacture mically. This contrasts with the Sudan to the footvalve. Problems also arose from in a country with only low indus- trials, where the India Mark lIs stood up swelling of the leather seals, which trial development (Category 1), well to very intensive use, but where the interferedwiththeplungerdownstroke. unless intensive technical assis- resources available for maintenance of Overall, the India Mark II proved to tance is provided to the manufac- such pumps are scarce. In one survey of be a durable pump, but one which is far turer (as was the case in Mali). It 50 pumps needing below-ground repairs in from easy to service when needed. scores o and oo for Categories 2 and 3 respectively. INTERVENTION CHARTS FOR THE INDIA MARK II FIELD TRIALS ARE ON PAGE 116 PUMP 09 115 India Mark 11 (standard) continued INDIA MARK II: CAUSES OF ESSENTIAL INTERVENTIONS 1- 1.25 -1.25 1 1.37 0.5 6 0.9- INDIA 0.96 SRI LANKA 0.8- * -1 _ 0 4 -OA 0.7 OJ~ -5 3C 8 0.7 * 0.65 -0.75 -0.75 0.6 -0.3 N OiO *0500 05 0.4 0.2 w 2 0.3 ~0.3 - i 0.2 -0.25 -0.25 0.2 * 0. 0.1~ 0 0 _ _ w _ . . _o 0@1~ W . . . W W l 0.0 _0 TMTAL HD F RH PR R4 PS PE FV OT TOTAL HD F RH PR RM PS PE FV OT PART REPLACED PART REPLACED 1- 1~ ~~ ~~~~~ ~ ~ 2 1 1.25 1 0.9- BURKINA FASO -1.75 0.9- NIGER "'0.8- 0.758 Or 2 2 .~~~~~~~~~~~~~~~~~-.5 15 0.75, co0.7- 00 007 125 .70. 60 = 0.4- * * C1 70.50 5 -1 054 * 0.50_ 0.4- 0.0. 0.3- _1 J ] 0.25g -025 t0l | . . . 1l . l . 11502-0.50 0.25 .0.2f.0.2. -0.25 0.1 - 0.250 0 0 0 00 0 0 0 TOTAL HO F RH PR RU PS PE FV OT TOTAL HO F RH PR RM PS PE FV OT PART REPLACED PART REPLACED 1 2.5 -1.75 1- 1.6 -4 0.9- SUDAN 150 0.9 -GHANA 1.4 -.5 0.8 - - 2 0. 2 2 2~~~~~~~~~~~~~~~~~~~~~~~~~~12 - 5 0.7- 12250.2 0. 6 - 1. 0.5, 1- 5 0.4- * _ Z} -o,75 510 0.8 - -0.6 2 5 0 ~~ ~~~~~~~~~~~~~~~~~~~~~~~~0.75 0. 0.4-0 0.6 -1.5 0.3 - 0.50w= 0.4. 0.2 0.5 a<00.21 00.3 - ~|w _ 1|. 0.5 -0.25 if 0.1 , 0.2 -0.5 0 0 O 0 -0 TOTAL HD F RH PR RU PS PE FV OT TOTAL HD F RH PR RM PS PE FV OT PART REPLACED PART REPLACED HD-Handle RH-Rod hanger RM-Rising main PE-Pumping element F-Fulcrum PR-Pump rod PS-Piston seal FV-Foot valve OT-Other 116 PUMP 09 India India Mark 11 (modified) General Description In a timed experiment on the deepest pump (standing water level 27 meters, Assessment cylinder setting 33 meters and operating The modified version of the India Mark 11 10 hours a day to serve 1000 benefi- The experimental modilied ver differs from the standard version in that it ciaries), impressive times were set for sions of the India Mark 11 have has pumping elements which can be removal and replacement of downhole given encouraging early results, removed without having to lift out the components, as follows: but there are limited dala (eleven rising main. An open-topped cylinder is pumps for oess lhan two years In used in a 2-1/2 inch galvanized steel . Removal of the pumphead took 2 one situalion) Judgmenis should rising main (experiments are also going on minutes therefore be regarded as preli with PVC rising main). minary at this stage. The pump has a "quick change" drive The plunger and footvalve were lifted Discharge Rate head, and versions are being tested with to the surface after a total of 17 The moditicaions do not alter the fixed or removable footvalves. Some minutes pumps discharge capaciry. andi experimental pumps have also been fitted atings are the same as tor the with nitrile rubber seals in place of the * Replacement to water flow took 25 standard India Mark I1 (Pump 09). standard leather cupseals. miue,including the time needed to Ease of Maintenance The purpose of the modifications is fl27minters, ofnsgmi.Though the modifications still do to make maintenance easier, by reducing m etes ofcrising main, not allow the Mark 11 to be the tools needed and the time taken to The original nitrile seals were refitted, as regarded as suitable for vdllage service downhole components. Improved there was virtually no sign of wear. The qualify for a agood (oo) rating for seal life is expected from the nitrile complete operation was performed by a area-mechanic maintenance (sys- plungerseals. team of four and needed no special lifting tem Bl at all lifts tackle. A similar operation with the Reliability Field Trials standard Mark 11 would have spanned The simpler maintenance and several hours, and required lifting gear to nitrile seals seem likely to Eleven experimental pumps have been remove the rising main and cylinder. reduce the pump's downtime, monitored for approaching two years in In this experiment, the break-out improving the ratings to oo at 25 the Project field trials in Coimbatore force needed to release the footvalve was meters l,i1 and a daily output of District, Tamil Nadu, India. Early trials with very high, partly because of galvanic 4m3, and to adequate" at higher PVC rising mains on three pumps did not action between the brass and cast iron. flows and at 45 meters head. come up to expectations, and galvanized The design has been modified and should Corrosion Resistance steel main was substituted pending result in a break-out force of about 150- Galvanized pumprods and rising further research on PVC jointing and 200kg, easily achievable through the mains mean that the pump cannot support. leverageofastandard Mark II head. be recommended where ground. Of the six installations with fixed Though the experimental Mark Ils water is corrosive, though this footvalves, two experienced no failures in have been on trial only for a short period, rating may be altered if 17 months of monitoring with pumping lifts there are good grounds for confidence experiments with PVC rising main of 20-22 meters. Three pumps had leather that the design can have a big impact on are successful. cupseal failures, but then worked without the pump's maintenance needs. Mainte- Abrasion Resistance breakdown when nitrile seals were fitted. nance should be possible with one trained Replacement of leather cupseals The remaining pump suffered both ball mechanic and unskilled help from with nitrile rubber seals earns the race and rising main failure. There was no villagers. The reduced amount of tools modified Mark li a o rating, failure of the fixed footvalves. needed means that a bicycle or motor Manufacturing Needs Five pumps were fitted with cycle should be the only transport The modifications do not affect footvalves designed to be extracted needed. the Mark IlI's suilability for through the cylinder and rising main. It is still hoped that PVC rising main manufacture in developing Though the monitoring period is short may prove suitable for use with the India countnes, and ratings are (only five months data available for this Mark 11. The initial problems involved therefore the same as those for report), initial indictions are that the failure of both solvent-cement and the standard India Mark 09 (Pump pumps are performing well. More threaded joints. PVC tension connectors 09). significantly, the modifications have had a are being tried, but fretting of the rising substantial impact on the time needed to main in the unlined hard rock boreholes service downhole components. still has to be overcome. PUMP 10 117 Philippines Laboratory Tests Date tested: 1983 Reported: Handpumps Project Report No. 3 .3i Performance data (typical values) - 46mm cylinder Head (meters) 7 25 45 Pumping rate (cycles/min) 40 40 40 Volume/min (liters) 12 11 11 Input (watts) 36 69 115 Mechanical efficiency (%) 36 63 72 Maximum handle force (kg-f) 4 7 11 Footvalve leakage (ml/min) No significant leakage il -K _ Evaluation after about 3000 hours and again shortly - < _ The two test pumps were securely packed before the end of the test. in a wooden case and arrived in good In the final inspection, all the internal working order. components of the cylinder were found to No installation and maintenance be in good condition, with few signs of instructions were supplied with the wear. The gland nut in the pumpstand was pumps. Rising main of 2 inch diameter is badly worn however, and corrosion was required and plastic pipe cannot be used observed on the piston rod, part of the General Description because the pumpstand is mounted cylinder clamp, andthepumpstand. directly on the protruding rising main. Impacts on the handle were The Jetmatic is made in the Philippines to Lifting tackle is likely to be needed for absorbed by the pumpstand turning on its a design similar to that of Kawamoto installation. Skill is needed to ensure that mounting thread. In the test on the body of Pumps of Japan. It is also available as a the cylinder is correctly installed in the the pumpstand, a moderate impact bent shallow-well suction pump (Pump 37). The rising main and that the pumpstand is the upper portion of the rising main cast iron pumpstand is compact and fits correctly mounted. Care must be taken sufficiently to prevent movement of the on the protruding end of the rising main, not to overtighten pumpstand fastenings, pumprod. Repeated shocks on the handle which must protrude at least 440mm to avoid breaking the cast-iron flanges. damaged the mounting threads in the base above ground to prevent the handle The bottom of the pumpstand is threaded casting. touching the ground and to provide 1.25 inch API and not the more common Users disliked the relatively low rate clearance for the spout. A discharge valve ISO pipe thread. of delivery and found the handle action in the spout allows either free discharge or The pumpstand may require frequent awkward. The handle moves through an pressure delivery through a hose or pipe. maintenance of worn handle compo- arc of about 1800, but for handle The deepwell cylinder is unusually nents and the gland nut. Appropriate hand movements near the upper and lower limits small (46mm bore), in order to fit inside 2 tools and a suitable stock of spare parts of its travel there is little movement of the inch rising main. It consists of a brass are therefore needed. Below ground, the pumprod. tube, gunmetal plunger and leather cylinder is designed to be extracted The overall conclusion of the cupseals. The plunger can be screwed on without removing the rising main. laboratory tests was that the Jetmatic to the footvalve to remove it without The 4000 hour endurance test Deepwell pump would be unsuitable for removing the cylinder. was carried out at 40 cycles per minute community use. The delivery rate is low with a simulated head of 45 meters. The and intensive use will be likely to produce Manufacture internal clamp securing the cylinder within rapid wear, failures in the moving parts in Gumetal and iron foundry work and basic the rising main had to be tightened soon the pumpstand, and breakages of the machining are required, with good quality after the start of the test, but this problem pumprods. Although potentially suitable control to ensure interchangeability of did not recur. Components of the handle for manufacture in some developing spare parts. mechanism were replaced because of countries, the design is by no means wear during the test. The pumprod broke ideal. Suppliers There are several, including Sea Com- mercial Co Inc, Cor. V. Cruz Street, Manila 2806, Philippines, who supplied the laboratory-tested pumps. Indicative prices - Feb 1985 Pumpstand and cylinder US$35 1 18 PUMP 11 Jetmatic Deepwell Field Trials Assessment In the absence of Project field trials, the Jetmatic Deepwell's ratings are based on its Photo not available performance in the laboratory and on the experience and judgment of Project staff. Ratings are for the Deepwell version; the Jetmatic Suction has been rated separately (Pump 37). Discharge Rate The small cylinder and awkward THE JETMATIC DEEPWELL PUMP WAS NOT FIELD operating action result in only an THE JETMATIC DEEPWELL PUMP WAS NOT FIELD '~~~~~adequate' (o) rating for all lifts. TESTED BY THE HANDPUMPS PROJECT Ease of Maintenance The need for special tools and lifting gear make the Jetmatic unsuitable for village-level (System A) maintenance. Area mechanics (System B) and mobile teams (System C) will find the pump relatively easy to maintain. The 'good' (oo) rating for System B maintenance reduces to o for depths beyond 25 meters, as the tests revealed that the cylinder retainer may not be reliable in the long term, so that lifting gear would be needed to remove the rising main. Reliability The laboratory tests suggest that frequent maintenance would be needed for lifts of 25 meters or more at discharges of 4m31d, and the pump is therefore rated .unsuitable" (-) in Tables S.3 and S.4. For 7m and 12m lifts, the pump earns a oo rating, reducing to o at 8m3/d. Corrosion Resistance The pump has no special protection against corrosion and suffered extensively from rusting in the laboratory tests. It cannot therefore be recommended for situations where groundwater is likely to be corrosive. Abrasion Resistance Use of leather cupseals means a - rating for abrasion resistance. Manufacturing Needs The Jetmatic Deepwell is not suitable for manufacture in coun, tries with a low level of industrial development (category 1) because of the need for foundry and machining skills. For categories 2 and 3, the ratings are o and oo respectively. PUMP 11 119 Germany, Federal Republic of Laboratory Tests Date tested: 1984 Reported: Handpumps Project Report No. 4 Head (meters) 7 25 40 . . < ~~~~~~~~~Pumping rale (cycles,min) 40 40 40 _ . ~~~~~~~~~~Volume;m,n (lters) 1 6 1 6 1 6 Inputtwattst 38 80 128 Mechanical efficiency (%) 43 75 75 Maximum handle force (kg-f) 4 11 18 Leakage of foot valve (mL,min) Not signiticant 'The volume dischargedper stroke was 0 35.0 37 liters and was notaftectedby Hb t pumpng rate. Ii Evaluation the joint was still serviceable. The two pumps acquired for testing were The impact tests caused distortion well protected and both arrived in working of the pumpstand body which was enough order, though the cases were large and at 300 Joules to affect the alignment of difficult to manhandle. the rising main (the manufacturer has sub- General Description An installation manual provided sequently doubled the thickness of the concise and clear instructions. No lifting pumpstand base to 1 Omm. The handle too The Kardia is a deepwell force pump with a tackle is needed for installation. Rising has been strengthened, following a failure conventional reciprocating action. The main and pumprod are supplied to length, in the laboratory shock test. The handle piston has a proprietary molded rubber lip and tools and PTFE sealing tape are failed after 54,000 cycles at the welded seal acting directly on the uPVC pipe supplied with the pumps. Area-mechanic joint between round and rectangular cylinder bore. Plunger and footvalve are maintenance is relatively simple, as sections. similar in design, machined from uPVC and there is no requirement for lifting equip- The Kardia consistently delivered fitted with flat rubber sealing washers. Two ment, but the special tools supplied by the just under 0.40 liters per stroke, both plunger seals are recommended for manufacturer must be retained. before and after the endurance tests, equi- depths beyond 35 meters. Recommended The Kardia went through the 4000 valent to a discharge of 16 liters per rising main is the manufacturer's own hour endurance test without break- minute at the selected pumping rate of 40 special plastic pipe with threaded connec- down - the test was conducted at 40 cycles per minute. tors and rubber sealing washers. The strokes per minute, with a simulated head The discharge rate remained pumprod is stainless steel with conven- of 30 meters. Damage did occur to the constant for heads ranging from 7 meters tional brass tube-nut couplings. cylinder bore and plunger seal during the to 40 meters, though the work rate clearly The pumpstand is fabricated from first 1000 hours of pumping, but this was increased (from 38 watts at 7 meters to sheet steel and sections and hot-dip galva- caused by debris from corrosion in the 128 watts at 40 meters pumping lift). nized and the handle bearings are large CATR head simulation valve, and Some users thought that the proprietary ball races in flanged housings. represents a condition unlikely to arise in Kardia's delivery rate was rather low, field conditions. though most liked the smooth action of the Manufacture At the end of the endurance test, pump, and smaller users in particular liked The pump could be manufactured in devel- sand was embedded in the plunger seal the moderate operating effort. The handle oping countries with steel fabrication and and both the seal and the cylinder wall height and movement seem to be a good machining expertise, but high levels of were scratched, though performance was compromise between the preferences of skill and quality control are needed to not impaired. A slight step was noted in short and tall users. produce the pumpstand. Skill is also the cylinder bore at the top and bottom of Overall, the Kardia was found to be a needed in machining the plunger and the plunger stroke. Center holes of valve reliable handpump in which modern mate- footvalve components. blocks in the plunger and footvalve were rials have been used to update a conven- worn but still serviceable, and there was tional plunger action design. Relatively Suppliers no corrosion. Some play was found in easy to maintain and repair, the pump is Preussag AG, Moorbeerenweg 1, the joint between handle and pumprod, but seen as suitable for community water Postfach 6009, D-3150 Peine, Federal again performance was unaffected and supply use for depths down to 30 meters. Republic of Germany. Indicative prices - Mar 1985 Per unit for 20m depth US$ 900 Extra pipe per meter US$ 14 120 PUMP 12 Kardia Field Trials Test conditions Assessment T. EL- The Kardia ratings are based on Number Head Data laboratory test results and perfor of range available - mance in field trials, though with a Country pumps (meters) (months) - limited number of pumps China 12 6-25 12 Discharge Rate China 12 6-25 12 Y Y At lifts of 25 meters and more, the Burkina Fasol1 Kardia achieves a "good (oo) - _ , ^ } F discharge (note that the ratings in rated it as reliable but slow (low dis- m~~~~anufS.4actrer) for lowe lift, whec i In the China field trials, the Kardia was Table S.4 are for 40m lif, which is very popular among the villagers, who the maximum recommended by the rated it as reliable but slow (low dis- ~~~~~manufacturer). For lower lifts. The charge). It was the only pump which could pump is only rated hadequatehi (d continue to operate during the severe about the long-term durability of the uPVC in comparison with the high d,s winter of 1984/85, when freezing cond- rising main, particularly in view of past charge pumps available for these itions caused others to cease to function. experiences with plastic rising mains at lifts. Ice in the upper rising main made the depths beyond 25 meters. EaseNof Maintenance Kardia heavy to pump and led to handle A single Kardia pump has been No lfting tackle is needed for breakages at the welding point. The prob- monitored in the Burkina Faso field trials, maintenance of the Kardea which lem could be avoided by drilling a small where it performed well, delivering a earns a oo rating under main hole in the rising main a couple of meters consistent 1.4-1.7 cu m/h at 50 strokes tenance systems B and C for lifts below ground, to allow bleed back when per minute. up to 25 meters Al greater pumping ceased. Further field trials are needed to deplhs, area mechanics may need The Kardia's plastic cylinder proved provide conclusive data on the long-term assistance, so the ranng drops to durable, but some doubts were expressed performance of this pump. Resiability A combination of wear rates and more difficult maintenance at deeper settings results in the reliability ratrngs dropping from oo at 7m and 12m lifts for daily outputs up to 4m3/d, to o at 25m lift and 4m3/d and "unsuitable" (-) for greater depths or daily output. Corrosion Resistance Use of stainless steel pumprods with brass connectors and a PVC rising main, plunger and cylinder, results in a oo rating Abrasion Resistance The pump did not break down during sand pumping in the laboralory trials, but sand embed- CAUSES OF ESSENTIAL INTERVENTIONS ded in the seals at the end of the 1- -1.50 3 trial, and wear in the PVC cylinder, 0.9- mean a general rating of o for | 0.8- -1.25 -2.S n abrasion resistance. In0.8- 1.25 -2.5 Manufacturing Needs ° 0.7- 21i : High levels ol skill and quality S; 0.6- * * E -2 o control are needed In the manufac- 3 0.5 0.75 O. s. ture of the pump, though the 0-07 1.5 u design is seen as suitable for D 0.4- many developing countries. C 0.3 - -0.50 -1 Ralings are oo for a country with a t 0.2 - - M C well-developed industrial base, o 0.25 -0.5 g where the industrial base is 0.1 moderately developed, and - 0 . - 0 where industrial skill levels are TOTAL HD F PH PR RM PS PE FV OT low. PART REPLACED HD-Handle RH-Rod hanger RM-R,.ing main PE-Pumping element F-Fulcrum PR-Pump rod PS-Piston seal FV-Foot valve OT-Other PUMP 12 121 Thailand Laboratory Tests Date tested: 1983 Reported: Handpumps Project Report No. 3 Performance data (typical values) -3 Inch dia. cylinder Head (meters) 7 25 45 Pumping rate (cycles/min) 40 40 40 Volume/mi (liters) 16 14 14 Input (wans) 33 106 133 Mechanical efficiency(%) 53 53 76 Maximum handle force (kg-f) 1 1 20 28 Footvalve leakage tmlim,n) No leakage wnen new 4.8 at end of test Evaluation end the rack and quadrant were comp- The two test pumps were packed in letely worn out. The plunger and cylinder l 4. wooden packing cases, one containing were also worn, though still serviceable, the pumpstands, the other the handles, and there was no reduction in pump perfor- rising main and pumprods. They were in mance. The leather cupseal in the foot- working order, but had a number of valve had compressed, allowing metal-to- 9 t 3 ~~~~~~~~defects which could have caused prem- metal contact and causing the valve to ature failure if not remedied before instal- leak. _______________ lation. In particular, it was necessary to Considerable corrosion was appa- seal the cylinder end caps with shellac, to rent on the ferrous parts of the pump, and overcome porosity in the gunmetal particularly on the lock nut between the castings. connecting rod and the plunger. General Description No instructions were supplied for In the impact tests, the pump was installation or maintenance. If galvanized undamaged by impacts to both the handle The Korat is a deepwell force pump. The steel pipe is used, lifting tackle is needed and the pumpstand body. The Korat also pumpstand is constructed primarily from for installation. A multi-size spanner completed the allotted 96,000 cycles of eight iron castings. It must be mounted on was provided by the manufacturer, but the handleshocktestwithoutfailure. a plinth to provide clearance for water several other tools are also necessary. The pump was not well received by containers under the spout and to accom- The pump must be installed on a plinth at users. The handle was long, but the modate the full movement of the long least as high as the largest water con- stroke was short, and many people comm- wooden handle. Handle bearings are tainertobeplacedunderthespout. ented that the handle was uncomfortably sealed ball races. Routine maintenance will involve high. As a result, most of the required Below ground, the cylinder is conven- regular lubrication, but should be easy. If effort had to be supplied by arms and tional, with a drawn brass barrel and cast adequately greased, the cast iron quad- shoulders. end caps enclosing a cast piston fitted rant and rack should not wear out in less The overall conclusion of the with leather cupseals. There are two foot- than two years. The entire below-ground laboratory tests was that the Korat is an valves, one in the base of the cylinder and assembly must be extracted for cylinder unrefined but rugged design, suitable for a second at the end of a short diptube. As maintenance, and lifting tackle is neces- manufacture in developing countries with an alternative to the cast rack and quad- sary. established foundry skills. Although not rant mechanism in the pumpstand, the The 4000 hour endurance test popular with users, it has the capacity to manufacturer now offers a chain and was carried out at 40 cycles per minute supply the needs of a community. Below quadrant assembly. with a simulated head of 45 meters. The ground maintenance is difficult, but the rack guide rollers in the pumpstand seized cylinder itself proved generally reliable. Manufacture towards the end of the test, and by the Foundry skills are needed. Suppliers Saha Kolkarn Factory, 94-96 Soi Sukapiban 2, Ramintra, Bangkhen, Bangkok, Thailand Indicative prices - Sep 1985 Pumping unit US$ 150 Pumprods per meter US$ 1.50 122 PUMP 13 Korat Field Trials Test_conditio__ns Assessment Test conditions r . The Korat ratings are based on NubrHead Data hfhIIIIII~ALboth field and laboratory testing, of range available and relate principally to the 608C Country pumps (meters) (months) : . seres. _ ' ti ~~~Discharge Rate With the right choice of cylinder, Thailand 94 6-23 21 1 the Korat is capable of achieving ,w,_________.=,___________ _ _ , -, . ..a 'good" (oo) discharge over the i * 16, iz . v ~~~~~~~~full range of pumping lifts. The Korat 608 design is in transition. The io ful rEase of Maintenace original rack and pinion action was - . The pump is not suitable for modified in the 608C series to a chain and ~ , i village-level maintenance (Sys- quadrant, and is being modified again in - ^- tem A). An area mechanic could the 608 CTS series. The Korat 608CTS is - readily carry out routine mainte- expected to become a standard pump in ' nance operations on pumps with 7 Thailand's rural water supply program, and or 12 meter lifts, but the need for the design is intended to be compatible lifting gear reduces the oo rating with below ground components being _ for System B at these lifts to developed for the modified India Mark II ' _adequate'(o)at25mand45m. (Pump 10). Reliability Of the 94 field trial pumps, 50 were of The frequency of maintenance the original 608A1 design, 40 of the later cylinder would result in high pumping interventions needed and the 608C design, and 4 were of the 608CTS efforts being required, as the laboratory need for assistance from a design. One important change has been a test showed, and this would put extra central maintenance team, reduction in the manufacturing accuracy stress on the pumphead. reduces the Korat's reliability needed to ensure interchangeability of For these deeper lifts, smaller rating to o for a daily output of spare parts. cylinders are available, with corres- 4m3/d at 25m lift, and to With its standard 3 inch cylinder, the pondingly reduced discharge rates. 'unsuitable" (-) for 8m3/d at the Korat produces a high discharge, and this The Korat 608C showed great same lift andfor4m3/d at45m lift. cylinder was used for the comparatively potential in the field trials, and further Corrosion Resistance shallow lifts of the Project field trials. For development of the CTS series should The pump suffered appreciable lifts of 25 meters or more, the 3 inch improve its reliability still further. corrosion in the laboratory tests, and is not suitable for use with corrosive water. Abrasion Resistance Use of leather cupseals means a - rating for abrasion resitance. Manufacturing Needs Successive modifications to the Korat have reduced the degree of manufacturing accuracy and quality control needed. The pump CAUSES OF ESSENTIAL INTERVENTIONS is well suited for manufacture in 5. ______________________________________________ _ -countries with medium or high 5 - -1.50 - 3 level industrial development, 4.5- 2.5t scoring oo for categories 2 and 3. a 4- | -1.25 !R -2.5 * w M w extensive field trials and in the of range available Whrain Country pumps (meters) (months) laboratory. Where ratings depend Malawi 117 5-27 36 Maldev has been rated on the Kenalawi 117 5-27 36 14 /0-3-1 basis of conventional compo- Kenya 14 10-35 19 t r sr _i nents, as used in the majority of Tanzania 10 3-16 9 the field trials.Better ratings may Philippines 35 6-40 20 .be possible with modern down hole China 34 9-26 10 components. corrosion problems. The assessment of Discharge Rate the Maldev has been based on its use with The choice of cylinder size and An important result of field trials on the conventional downhole components. variable handle length mean that Maldev has been the comparison between Most pumphead breakdowns were high discharges are possible at all bearing performance in the older proto- due to ball bearing failure. If allowed to lifts, earning the pump a uniform type heads, constructed with poor quality progress, bearing wear can have serious 'good" (oo) ratng. jigs and fixtures and installed in 1982, and consequences. There were several Ease of Maintenance that in the later heads where both jigs and examples where collapsed bearings The conventional downhole comp- quality control were much improved. The resulted in balls falling down inside the unsuitables (-) for village-level later production heads have given ball rising main and damaging the cylinders. unitable forvile-level bearing life some 2-3 times longer than in The Maldev's T-bar handle was depth. Area mechanics would the older heads. This underlines the popular with users, who also liked the high need support from mobile teams importance of manufacturing quality con- discharges made possible by selection of for repairs at 25m and 45m, so trol, even in such a simple pump as the appropriate cylinder sizes and handle that the rating for maintenance Maldev. lengths. system B drops from oo to Although the Maldev head was As a first attempt at development of 'adequate" (o) forthese lifts. designed for use with plastic rising mains adeepwellhandpumpsuitableformanufac- Reliability and extractable cylinder components, ture and simple maintenance in Africa, the The maintenance ratings also only few of the pumps on test had this Maldev was mainly successful. Introduc- affect the ratings under this type of assembly and all were prototypes. tion of plastic bearings, as on the Afridev, heading, giving the pump a oo Most test pumps used conventional down- should improve the pump's reliability and rating at 7 and 12 meters lift and hole components, and in consequence ease of manufacture. daily outputs up to 4mj d. were difficult to maintain and had reducing to o for higher lifts and discharges, and to - for 45m lift and for a daily output of 8m3/d at 25m lift. Corrosion Resistance Galvanized steel pumprods and rising mains mean a- rating. Abrasion Resistance CAUSES OF ESSENTAL INTERVENTIONS Use of leather cupseals means a 1 1.2 - 1.50 rating for abrasion resistance. 0.- -1.2 -1.50Manufacturing Needs 0.8- MALAWI -125 Judging Ihe pumphead only, X0.8- i .manulacluring needs for the ° 0.7- b Maldev are simple, and it eams a O. _6 -o-s e, -'aetoo rating for manufacture in 0.6- countries with moderate or high M.6 -0.7 levels of industrial development tWL 0.4_ 0 (Categories 2 and 3), reducing to 03 -0.4 -0.50 o for Category I (low industrial C 0 *mm base), because of Ihr- demon- ,! 0.2- | | | -0.2 -0.25 strated need for good quality jigs 0.1- * 0 to ensure reasonable bearing o- w ^ w iw ib 8 ^ - r -o -o performance. TOTAL HD F RH PR RM PS PE FV OT PART REPLACED M PROT. rE PROD. HO-Handle RH-Rod hanger RM-R,sing main PE-Pumping element F-Fulcrum PR-Pump rod PS-Piston seal FV-Foot valve OT-Other PUMP 14 125 Canada Laboratorv Tests Date tested: 1984/85 Reported: World Bank Applied Technology Note No. 2 Performance data (typical values) - 2.25 inch dia cylinder Head (meters) 7 25 45 Pumping rate (cycleslmin) 40 41 40 Volume/min (liters) 14 15 14 Input (watts) 43 92 138 _____ > Mechanical efficiency (%) 37 66 - 76 Maximum handle force (kg-f) 6 13 20 Footvalve leakage (mlmin) No significant leakage Note: The volume discharged per stroke was about 0.35 liters, and was not affected by pumping rate. Evaluation breakdowns occurred in the 4000 hours. g 1D e I ~~~~~~~The Monarch handpump was originally The misalignment of the pumprod trunnion tested by CATR in 1979/80, as part of the caused it to move sideways at each - ODA program. Since then, the manufac- stroke reversal, resulting in a knocking turer has introduced a number of modifi- noise and wear on one side of the guide cations. The present samples were supp- bushes. General Description lied with 2.25 inch Clayton Mark cylinders. In the final inspection, handle The two samples were well packed, bearings were found to be loose in their The Monarch is a conventional deepwell though the single packing case with a recesses and the shoulder bolts were pump with a cast iron pumpstand and weight of 289 kg was difficult to manhandle loose. The galvanized steel pumprod was integral cast iron pedestal. A plastic guide and might be damaged by rough treatment. severely corroded immediately above bush and gland ensure that the upper Both samples had some free movement in the plunger and the iron nipple between pumprod moves in a straight line, and the the handle pivot bearings, and the trun- the cylinder base and the lower footvalve steel handle is attached by a swinging nions for attaching the pumprods to the was also badly corroded. The lower leather link. Handle bearings are sealed ball handle link were not square with the rods. cupseal was split, but otherwise the races. A T-bar handle is offered for two- A comprehensive instruction plunger and both footvalves were in good person operation at higher lifts. manual is available, in English and French condition and there was little sign of The brass tube cylinder has a gun- and includes a useful checklist of possible cylinderwear. metal plunger with two leather cupseals. A troubles and remedies. For developing In the impact test, the pumpstand footvalve is incorporated in the lower countries, more illustration and less text broke above the baseplate at an impact of cylinder end cap and there is a second may be more appropriate. 150 Joules (the normal maximum impact is footvalve with 0-ring seal below the Lifting tackle is essential for pump 500 Joules). The fracture appeared to cylinder. Several cylinder diameters are installation, in addition to the compre- originate at the inspection hole. Because available to suit different depth ranges, hensive tool kit supplied with the pumps. of this failure, no handle impact test was and pumprods can be supplied as In some installations it may be necessary carried out, but the handle completed the galvanized steel, stainless steel, or glass to cut and rethread the pumprod. 96,000 cycles of the handle shock test fiber reinforced plastic (GRP). Pumpstand maintenance generally withoutfailure. should require only basic tools, though a Users found the pump comfortable Manufacture drift may be needed to remove and replace and easy to use. High quality iron and gunmetal foundry handle bearings. Below-ground main- The overall conclusion of the work is required to ensure the interchange- tenance, such as footvalve repair or laboratory tests was that the Monarch is ability of spare parts and the correct replacement of leather cupseals involves easier to operate at 45 meters depth than functioning of the pumphead. extraction of the rising main and therefore many other pumps. The cast iron pedestal requires lifting tackle. Use of two foot- needs strengthening to withstand acci- Suppliers valves can give rise to unnecessary dental impact or abuse, but otherwise the Monarch Industries Ltd, 889 Erin Street, problems. If the upper footvalve fails but pump proved reliable. One footvalve would Winnipeg, Manitoba, Canada. the lower one continues to function, be sufficient. broken parts can damage the cylinder, Corrosion can be expected to cause Indicative prices - Feb 1985 plunger and seals. problems in aggressive waters, though the The 4000 hour endurance test availability of alternative pumprod and Pump plus 2.25 inch cylinder US$300 was carried out at 40 cycles per minute, rising main materials should alleviate Pumprod (GRP) per meter US$ 2.60 with a simulated head of 45 meters. No some of them. Rising main per meter US$ 8.80 126 PUMP 15 Monarch P3 Field Trials Assessment Test conditions F i t The Monarch P3 ratings are Number Head Data ' uuin~m. gS ~ p >,,,based on laboratory and field test ofmb r Hang Dataial At results. of range available .> ~ ' k ''' '_a Discharge Rate ________________________________ With the right choi~~~ce ot cylinder Country pumps (meters) (months) With the right chol Ghanar 65 6-20 22 size, to suit the pumping lift, the Monarch P3 is capable of achie- inch guide rods have been monitored in _ ving a "good" (oo) discharge rate for the full range of pumping lifts. A total of 65 Monarch P3 pumps with 3/4 !. ' lav Easeof Maintenance inch guide rods have been monitored in v S . | L_ he atie c aed pumpi the Bolgatanga region of northern Ghana. head and thecnee for lifin The pumps were equipped with 3 inch tackle and special tools makes diameter cylinders, 7/16 inch diameter r - - - the Monarch "unsuitable" H) for galvanized pumprods, and 1.5 inch . zi village-level maintenance irres- diametergalvanized pumprodsing mainds1.5 inch v _pective of depth. Area mechanics diameter galvanized rising mains. would need support from mobile On installations below 15 meters, _ ;_ _ ___ teams for repairs at 25m and 45m. heavy lifting equipment was needed to The rating for maintenance Sys- install the pumps, which also need special Te is for reduce from tools for assembly of the pumpstand. temn B Is therefore reduced from Maintenance of downhole compo- Breakdowns were caused mainly by 00 to s adequate" (o) for these nents also means the use of lifting tackle, disconnected pumprods, broken guide lifts. as the complete assembly has to be rods, broken pumprods, loose piston rods, Reliabieity removed to change seals or repair valves. and loose followers. The main causes of On the basis of interventions The 3 inch cylinder gives the poor performance were broken shoulder needed during the field trials, the Monarch a good discharge rate - in the bolts, poor well yield, damaged shackle pump eams a oo rating for range of 1.0 to 2.0 m3/h, which proved bearings, defective footvalves, leakage at reliability at 7 and 12 meters lift popular with users. Nine pumps were fitted rising mains/couplings, leather cupseals, and daily outputs up to 4m3/d, with water meters, and the amount of and damaged fulcrum bearings. The reducang to - for higher lifts and water pumped per day ranged from 2.8m3 broken guide rods generally resulted from discharges and tou- for 45m lifts to 1 Om3, with an average of 6.8m3. Those broken shoulder bolts or damaged shackle and for a daily output of 8m3/d at results covered the six months from April bearings, and led the manufacturer to 25m lift. The improved version of to September 1986. In March 1986, one redesign the pumphead. Since modifi- terratisl Monarch P3 reached an average daily cations were made, pumphead defects betterrratings. discharge of 1 6.5m3 have fallen substantially. Corrosiion Resistance During the 22 months of monitoring, Three of the Monarch pumps were The standard version of the the 65 pumps suffered a total of 58 equipped with GRP rods, which performed Monarch P3 is rated unsuitable breakdowns and needed 61 further without breakdown for the 21 months for use with corrosive water interventions to correct poor performance. during which they were monitored. rods and rising mains. Alternative materials are available as options. Abrasion Resistance CAUSES OF ESSENTIAL INTERVENTIONS There were no sel failures durng 10 -20 -30 the laboratory tests, and few in 9 the field trials, but use of leather ^ 8 16 -25 n cupseals means a- rating. a - x Manufacturing Needs ao 7 * 0 -20 O Manufacture of the Monarch P3 -12 demands strict quality control and U S 1 8 -t5 a a high level of foundry skills. It is 5 - e ffi ! not therefore suitable for manufac- = - In -10 e6 ture in a counmry with a low level of p_ 3 - ,t10 industrial development (Category i. 2 - _ _ -4 1). The o rating under Category 2 2 _5 _ _indicates that some external I | * * _ * s assistance may be needed Wnlh T P0 0 quality control. Tne rating for Cate PART REPLACED gory 3soo. HD-Handle RH-Rod hanger RM-R1sing ma.n PE-Pumping elem.enli F-Fulrcru PR-Pump rod PS-Pislon seal FV-Foot valve OT-OShe, PUMP 15 127 United Kingdom Laboratory Tests Date tested: 1984 Reported: Handpumps Project Report No.4 Performance data (typical values) Head (meters) 25 45 60 Gearbox ratio 3:1 2:1 3:1 2:1 2:1 X | 11 Pumping rate (cycles/min) 40 40 40 40 40 Volume-min (lers) 16 10 16 10 9 Input(watts) 135 89 191 125 139 Mechanical efficiency (%/) 48 48 59 61 65 Maximum handle force (kg-f) 15 10 20 14 15 Footvalve leakage (mlmin) No significant leakage Evaluation The Monolift was originally tested in easier to use, and children much preferred 1983/4, when only a 3:1 gearbox was the 2:1 gearbox (intended to extend the available. Performance and user tests pump's range beyond 45 meters). were repeated more recently on a modified The overall conclusion of the General Description version of the pump with both 3:1 and 2:1 laboratory trials was that the Monolift is a The Monolift is a positive displacement gearboxes, thermoplastic gears, a modi- robust pump, suitable for community water Thpe ll IS handpump pofthe distablihem t fied pumpstand and handle arrangement, supply use at depths of 20-45 meters, but deepwell handpump of the estabigshed andanewcompoundforthestator. not suitable for village-level maintenance. Mono progressing cavity design, with a TheMonoDirectDrivepumpmanufac- The optional 2:1 gearbox extends the double helical steel rotor and a trple tured in South Africa has also been tested range beyond 45 meters and the new helical elastomerc stator. Two rotary in the laboratory. This report combines version is more suitable for children. crank handles allow one or two people to results from the three sets of laboratory operate the pump. Drve Is through bevel tests, to give an overall evaluation of the The Mono Direct Drive gears, with a ratchet mechanism to Mono pump types. The figures in the ensure correct rotation. The pedestal is performance table above are from the later fabricated steel. Steel gears in an oil-filled model of the Monolift and were generally gearbox were for a time replaced with the same as or better than those in the thermoplastic gears requiring no lubri- orginal trials. cation, but Mono has now reverted to oIgnaltrals.in ad maneac metal gears, this time using a long-lasting of the Mono pump requires lifting greasePlubincant. equipment and skilled mechanics. Work- Pumping elements are designed for shop facilities are needed to repair gears water temperatures of 16-400C. A proprie- and pumping elements must be replaced tary all-plastic footvalve is fitted. entirely when faulty. A direct drive version of the pump, The older design of the Monolift was with no gearbox and the handle connected subjected to endurance testing at 40 directly to the pumprod is available from cycles per minute with a simulated head of Mono Pumps (Africa) in Zimbabwe and 45 meters. The pump completed the tests South Africa. without failure, except for wear of an uniub- Laboratory users did not like the ricated handgrip during the first 100 hours. operation of the direct drive pump, finding Manufacture At the end of the 4000 hours, the it difficult to sustain effort through a Special skills and equipment are required outer surfaces of the rotor helix were scrat- complete revolution. to make the pumping element and the ched and the inner surfaces had deposits The pump also performed badly in gearbox. of rubber from the stator, but the pumping endurance tests, with failures in both element was still serviceable. There was the drive head (now redesigned) and the Suppliers some corrosion of the pumping element pumping element, suggesting that Mono Pumps Ltd, Arnfield Works, end caps, but otherwise no noticeable frequent attention might be needed in Audenshaw, Manchester M34 5JA, UK. corrosion. community water supply use. The delivery The pumpstand withstood the rate was low, without the advantage of the Indicative prices - Feb 1985 impact tests without damage. gearbox. Some users, particularly small The laboratory concluded that Completerassembly to children, found the old design difficult to considerable further development would 3meters depth US$ 353 operate. The shorter pedestal and handle be needed to make the pump suitable for Extra rods per 3 meters US$16 modifications have made the new model community water supply. 128 PUMP 16 Monolift Field Trials Assessment Test conditions _ Test_____________________ _ cnios The Monolift ratings are based on Number Head Data ____ ~~~~~~~~~~~~~~~~~~ laboratory tests and limited of range Data iae ;w. monitoring in field trials. Country pumps (meters) (months) av a Discharge Rate Country pumps (meters) (months) ~~~~~~~~For low lift applicaiions. where China 10 9-60 12 overcoming friction in the pum- Bolivia 19 10* 10 -, ~~~~~Aping element represents a signi- Bolivia 19 9-60 12 , J i *, _. wcficant part of the pumping effort, *Average lift -' the pump would have to be monitored as. - fthe,,worked very hard to deliver Only a few Monolift pumps have been enough water to compete with monitored as part of the Project, and the ;lisL pumps designed specifically for field information is supplemented with , shallow lifts. In deep wells, the reports received from other users. Monolift can compete more In general, the Monolift is a popular readily and earns an nadequaten pump with users, who find the discharge (a)ratingforallbutthe7mlift. rate and the reliability acceptable and tend - .; r fo E as e of Maintenance to favor the pump over equivalent lever Maintenance is complex and action pumps. requires special skills and In China, where the pumps were very equipment. The pump is not heavily used - serving 200 users per parts - the pumping element and the suitabpe for village-level or area- pump and operating from sunrise to gears - are replaced rather than main- mechanic maintenance. sunset - the Monolift and the Kardia tained. Long service life is therefore criti- Reliability (Pump 12) were the most popular pumps in cal in village use. The manufacturer has The Monolift is a durable pump the trials. now ceased manufacture of pumps with and earns a "good" (oo) rating for However, the China trials also thermoplastic gears and is offering replace- lifts up to 25 meters and daily revealed flaws in the thermoplastic bevel ments to existing users. The new gears outputs up to 4m3/d. For 45m lifts gears which were introduced for a short are metal castings with a stainless steel or for 8m3/d output its rating is time by the manufacturer. The gears and shaft and a new non-return mechanism. reduced too. the ratchet system used with them did not The pump's below ground compo- Corrosion Resistance prove durable enough. Similar problems nents are durable, and the progressing With galvanized pumprods. the have been reported to the Project from the cavity design is comparatively resistant to Monolift is not suitable for use Sudan, where about 100 Monolifts with sand pumping, but maintenance when withcorrosivewater. thermoplastic gears also suffered failure needed is difficult and requires a fully Abrasion Resistance within four to six months of installation. trained mobile team. The progressing cavity design The Monolift is a pump in which key copes well with sand-laden water, and earns the Monolift a oo rating for abrasion resistance Manufacturing Needs Specialized processes are inv- olved in the manufacture of the pumping element and very tight CAUSES OF ESSENTIAL INTERVENTIONS quality control is essential. The 1- 2 -2 gearbox too requires tight quality 0.9 -2 -2control. The Monolift is not o.s - CHINA therefore suitable for manufac- 2 0.8- . = = ture in a developing country which g 0.7 1.5 does not have an advanced 0.6 . g. industrial base. However, 0.6- Q manufacture of the Direct Drive ! 0.5- - I 1 j -1 q Mono pump in Zimbabwe shows 0. WL 0,4_ - - a: D that there is scope for joint- 0.3- * - C ffi venture type manufacture, and C 0.2 0.5 -0.5 the pump is therefore rated oo under manufacturing environment 0.1- * * 0 3. TOTAL HD F RH PR Rm PS PE FV OT PART REPLACED HD-Handle RH-Rod hanger RM-R,s.ng main PE-Pumping element F-Fulcrum PR-Pump rod PS-Piston seal FV-Foot valve OT-Other PUMP 16 129 Canada, United States Laboratory Tests Date tested: 1983 (US model) plus 1985 engineering assessment of Canadian model. Performance data (typical values) IHead (meters) 7 25 45 Pumping rate (cycles/min) 40 40 40 Volume/min (liters) 9 8 7 Input (watts) 45 59 91 Mechanical efficiency (%) 22 59 58 Maximum handle force (kg-f) 9 10 14 Footvalve leakage (mi/min) No significant leakage Note: Operating force must be sustained throughout the working cycle. Evaluation been modified to eliminate the rubber The two test pumps were delivered in block. cartons made from heavy-duty corrugated Grease leaked out of the gearbox cardboard and reinforced with a wooden throughout the test, but plenty remained pallet. Both pumps were in good working at the end. Both rotor and stator were in order; one footvalve was bent but was good condition after the test. A consider- _____________ easilystraightened. able amount of sand was lodged in the No instructions were provided for footvalve, but it was still working. There installation or maintenance, though a well- was no corrosion of the working parts of General Description illustrated Installation and Maintenance the pump, but the paint on the cylinder manual is available from the manufacturer. barrel had not stopped some rust from The Moyno is a progressing cavity deep- A number of tools were supplied, including forming there. well handpump with a helical rotor turning a die and diestock for threading the Heavy impacts on the body of the in a double helical stator. A pair of rotary pumprod. The weight of the below-ground pumpstand produced no damage. Users crank handles means that the pump is assembly means that lifting tackle is consistently disliked the pump. Most of suited for one or two person operation. essential for installation, which requires the required effort has to come from the Drive is through bevel gears in a gearbox skill and understanding of the pump. It is arms and shoulders; there is little prepacked with lubricant, and a one-way especially important that the pumprod is opportunity to bring other muscle groups clutch to ensure correct rotation. cut to length and threaded accurately. into play. Smaller users, with limited The pumpstand is all-steel const- Frequent maintenance is unlikely reach, could not maintain a smooth ruction and very robust. The footvalve is to be required. A broken handle could be circular motion of the handles. Though the gunmetal. The steel rotor is chrome or easily replaced, but repairs to the gearbox absolute values of the required operating nickel plated. The Moyno can be installed could not be undertaken in the field. If the force do not seem great, people found it in a 75mm diameter well, and two pumping pumping element is faulty it must be rep- difficult to sustain the same effort elements are available - a single-stage laced as a complete unit, which requires throughout the pumping cycle. for depths down to 45 meters, and a lifting gear and the availability of a The overall conclusion of the double-stage, said to be suitable to 90m. replacement unit. In general, the Moyno laboratory tests was that the Moyno would requires an exchange rather than a repair- not be suitable for community water sup- Manufacture based routine. ply, except in unusual circumstances. Highly specialized skills and equipment The 4000 hour endurance test Though the pump proved reliable in the are needed to manufacture the pumping was carried out at 40 cycles per minute, laboratory endurance test, the rate of elementandthegearbox. with a simulated head of 45 meters. The discharge is small - significantly less pump failed once in the test. After about than the other progressing cavity type Suppliers 3000 hours, a rubber block, intended to pump tested by the Project, the Monolift The current model is made in Canada prevent the rotor from striking the base of (Pump 16). The Moyno is difficult and though an earlier model was made in the the cylinder during installation, became expensive to install, maintain and repair, USA and future production could be in entangled in the rotor and caused the and is unsuitable for manufacture in either country. Manufacturer is Robbins pump to seize. The cylinder has since developing countries. and Myers (Canada) Ltd, PO Box 280, Brantford, Ontario N3T 5N6, Canada. Indicative prices - Aug 1986 Single-stage unit to 45m US$ 410 130 PUMP 17 Moyno Field Trials Assessment Test conditions "'~, z Test condition' ~~' ~The Moyno ratings are based on Number Head Data , the pump's performance in both of range available I field trals and laboratory tests. Country pumps (meters) (months) Discharge Rate Country pumps (meters) (months) I ~~~~ The Moyno's comparatively low Burkina Faso 50 8-40 40 - _ , discharge rate mean that it CotedIlvoire 14 10-39 12 1cannot compete with the many Ghana'lvoire 14 10-39 12 9 i _ high discharge pumps available Ghana & v * v - , for low lift applications. For 25 and Kumasi 57 1-35 33 , 45 meter lifts, the pump achieves Bolgatanga 68 5-22 31 an 'adequate" (o) rating. Ease of Maintenance The Moyno had technical problems in the _ Servicing of the Moyno is complex and requires special early stages of the Burkina Faso and tools and equipment. It is Ghana (Kumasi) field trials. Main failures unsuitable" (-) for village-level involved scaling of the rotor nickel plating, which rub on each other. The result has (system A) or area-mechanic clutch failure, and wear of handle keys. been rod disconnections or breakages (system The manufacturer reverted to a previous and leakage through the rising mains. Remiability design with chrome plating, which In terms of pump performance, wear On the basis of the number of overcame the scaling problems. of the thrust spacer and leakage turned interventions needed during the The modified pumps proved quite out to be the most frequent causes of field trials, the Moyno earns a reliable and were generally well accepted essential interventions. 'goodod)rals n for ea,rns a by the users. The outstanding remaining In field operation, the discharge rate dgod (o) ratg fo 3relia4blity for problem is corrosion of the galvanized of the Moyno is in the range of 0.5 to rg p pumprods and rising mains. This has led to 0.8m3/h. The average daily output of the lifts or for 8m31d output its rating pumprod breakages, and to corrosion Bolgatanga pumps between April and is reduced to o. particles from the pumprods and rising September 1986 was 4.5m3. The pattern of Corrosion Resistance mains jamming the pumping element or pump use in Burkina Faso is similar to that se galvanize pumprs a blocking the footvalves. Taste problems in northern Ghana and involves much rising mains means a that the caused by corrosion products have led to heavier use than that in southern Ghana Moyno is unsuited for use with some pumps being disliked by users. and Cote d'lvoire, with high seasonal corrosive water. In the Ghana (Bolgatanga) field trial, fluctuations. During the dry season, AbrasionResistance the Moynos are equipped with 1 inch rising maximum daily quantities pumped with The progressing cavity design mains. This has led to damage to the rising Moynos in northern Ghana and Burkina copes well with sand-laden water mains and to pumprods and rod couplings Faso reached 1 2m3. and earns the Moyno a e rating. Manufacturing Needs Specialized processes are involved in the manufacture of the pumping element and very tight quality control is needed. The gearbox is complex and also demands Tighl quality control. The CAUSES OF ESSENTIAL INTERVENTIONS w Moyno is therefore not suitable 2 - 4 2 for manufacture in a developing 1. . X2 country which does not have an 1.8- -3.5 .- 1.75 3 advanced industrial base, and ; 1.6 Z z even then would require close $ g3 -1.50 <. collaboration with the original 1.4- < 1.2 2.5 t -1.25 z manufacturer. The pump there- fore earns a o rating only for , - 2 I manufacturing environment 3. C 0.8 1.5 -0.750 E 0.64 0.4 1 O~~~~~~~~~~~~~~~.SO 0.2 n0.5 - 0.25w 0 _ n« 1 0 -0C TOTALHD F RH PR RM PS PE FV O PART REPLACED GHANA I r1 GHANA If ra BURKINA HD-Handle RH-Rod hanger RM-Rising main PE-Pumping element F-Fulcrum PR-Pump rod PS-Piston seal FV-Foot valve OT-Other PUMP 17 131 Finland Laboratory Tests Date tested: 1986 Reported: Report notyetpublished Performance data (typical values) - 60mm cylinder Head (meters) 7 25 45 Pumping rate icycles -min) 41 40 39 Volume!min lI,ters) 23 22 21 Input (watis) 90 163 223 Mechanical effic4ency (%) 29 55 60 Maximum handle iorce (kg*f) 13 20 27 Foorvalve leakage (ml--min) No significant leakage L.) A UEvaluation At the same time, the included angle of the The two test pumps were securely packed valve seat was increased to 90°. in wooden cases, and were generally in At the end of the test, the plunger _____________ good condition on arrival, though the and cylinder were in good condition. There threaded studs on the bottom of the were few signs of wear on the valves, pumpstand delivery pipe were not straight though cracks had begun to appear in one sample. The manufacturer later around the integral retaining rings at the supplied polyurethane valve poppets to base of the polyurethane poppets. General Description replace the rubber valves in the original The manufacturer has since made consignment. further modifications to the valves, to A deepwell lever-arm force pump, which Installation instructions were supp- eliminate the need for integral retaining can be supplied with cylinders of 60mm or lied in English and were comprehensive rings. 50mm. The pumpstand is mainly fabri- and helpful. A full set of tools was also There was no corrosion. The cated from steel sheet, galvanized, and provided. Installation was easy. Lifting pumpstand was in good general condition, enclosing a molded rubber delivery cup tackle would be needed for galvanized but there were signs of wear on both the attached to the top of the rising main. The steel rising main and for stainless steel at connecting strap and the pumpstand stainless steel pumprod is connected to deep settings, but is unnecessary for body, as a result of misalignment during the handle through a flexible strap wrap- polyethylene. manufacture. ped round a quadrant, so the pump has a Maintenance instructions were The pumpstand body proved strong gravity return. Handle bearings are large very brief. The entire below ground in the impact tests. The handle was less ball races in flanged housings. assembly must be extracted to service robust however: heavy impacts on the Stainless steel, polyethylene or galv- the piston or footvalve, but this was easier handle caused it to bend slightly, though anized steel rising main can be used. The than for many deepwell pumps because of the pump could still be used without cylinder is a drawn brass tube with the relatively light weight of the pumprods difficulty. But in the handle shock test, the gunmetal endcaps. The plunger is also and rising main. The pumpstand design handle broke at the weld near the pivot gunmetal with a molded rubber cupseal. allows extraction of the rising main without bearings after 67,000 of the allotted The molded polyurethane poppet valves removingthepumpfromthewellhead. 96,000cycles. are identical in the plunger and footvalve. The 4000 hour endurance test In the user test, the pump was was carried out at 40 cycles per minute, generally well received by both adults and Manufacture with a simulated head of 40 meters. A children. Adults tended to use a full The pumpstand needs steel fabrication weight of 20kg was added to the pumprod stroke, whereas most children adopted a skills. Well equipped workshops with high to maintain tension in the strap connecting faster short-stroke technique. quality control are needed for cylinder the rod to the handle. In the overall conclusion of the manufacture. There were persistent failures of the laboratory tests it was noted that the AF84 original molded rubber poppet valves, for requires heavy rods or a deep setting to Suppliers which the included angle of the seat was ensure that the flexible strap connecting Vammalan Konepaja Inc, 38200 Vammala, 600. The poppets tended to extrude into the handle to the pumprod remains taut Finland. the valve seat under the pressure of the while pumping. water column. Moldings in a harder grade The final design for the plunger and Indicative prices - Sep 1986 of rubber were unsuccessful. In consul- footvalve should make a substantial tation with the manufacturer, the rubber contribution to the pump's overall Per unit for 40m depth valves were replaced with polyurethane reliability, but the Nira AF84 is unlikely to stainless steel rising main US$1396 moldings, both for this pump and for the be reliable if it is subjected to abuse or Polyethylene rising main US$1188 Nira AF85 direct action pump (Pump 32). heavy-handed use. Galvanized rising main US$ 1123 132 PUMP 18 Nira AF84 Field Trials Assessment In the absence of field tnals, ratings for the Nira AF84 are based on performance in the laboratory tests and on the -- J k it ' 5 experience and judgment of Project staff. Discharge Rate The comparatively high effort needed to obtain high output restricts the rating to 'adequate' (o) for all lifts. l J i Ease of Maintenance AA19 ; < ; ,. " :. ' The pump is not suitable for ., 1. - tN i r ' * -maintenance by a village caretaker (System A) even at > ) ;i ~~~~~~~~shallow settings. However, area g *1s A. smechanics (System B) and mobile teams (System C) will find the pump straightforward. The rating for both these systems for lifts up to 12 meters is 'good" (oo), reducing to o at 25 meters or more for System B, reflecting the fact THE NIRA AF84 PUMP WAS NOT FIELD TESTED BY THE that lifting tackle may be required. HANDPUMPS PROJECT Reliability In the laboratory tests, problems with the initial rubber valves cast doubts on the pumps reliability. With the improved design, the pump is expected to be more reliable and earns a oo rating for most installations, reducing to o for a discharge of 8m3/d at lifts of 7 to 25 meters and for 4m3/d at 45 meters lift. Corrosion Resistance All parts of the pump are made from corrosion resistant materials and it eams a oo rating. Abrasion Resistance The pump did not suffer abrasion during the laboratory tests. The cupseal is molded rubber and the cylinder is drawn brass. The abrasion resistance rating is therefore o. Manufacturing Needs Manufacture of the Nira AF84 requires facilities and skills which would not be available in a country with a low industrial base (category 1). However, much of the pump could be made in countries with medium-level industrial development (category 2). The ratings for categories 2 and 3 are therefore o and oo respectively. PUMP 18 133 Philippines Laboratory Tests The complete configuration of the local after only 280 hours of endurance testing, pumphead with either the Eureka or the Eureka cylinder, which was secured in Tagasago cylinders was not tested by the the rising main with an expanding rubber Project in the laboratory. However, a bush, as specified by the manufacturer, laboratory test of the Eureka cylinder became dislodged, preventing effective connected to a Philippine made Jetmatic operation of the pump. pumphead (Pump 11) was performed in The smoothness of the brass 1981 and reported in Project Report No. 1. cylinder wall was found to be excellent and Much of the data on the Eureka the mechanical efficiency of the unit was cylinder would not be applicable to the very good (71% when operated at 30 case where it is connected to a local strokes per minute with a lift of 45 meters). pumphead. However, it is notable that some pipe fittings and bolts to form a in place by rotating the cylinder and so pumphead and spout. The long handle has expanding a rubber sealing ring against a high mechanical advantage and thus the inside of the main. The footvalve fits in reduces the required operating force to a a taper in the bottom of the cylinder. The manageable level even when pumping plungerhastwoleathercupseals. from very high lifts (the Project has monitored lifts of over 80 meters). Handle Manufacture length and mechanical advantage vary The pumphead is specifically intended for from one installation to another. In the local manufacture in the Philippines and field trials the ranges were 3.7 to 4.9 could be made locally in other developing meters handle lengths and 11:1 to 15:1 countries, even with only low level mechanical advantages. industrial bases. The Takasago model HW-C65 The Eureka cylinder is manufactured cylinder, is a conventional design, but has in the Philippines. It demands at least a an open top to allow extraction of the medium level of industrial development plunger for maintenance. The 24 inch long with good quality control of brass brass cylinder has a 2-1/4 inch inside machining. The Takasago could also diameter and is intended for connection to probably be manufactured under similar C a 2-1/2 inch galvanized steel rising main. conditions, though it is presently imported The plunger is also made from brass and from Japan (there are also some unautho- uses a sequence of four leather cupseals. rized and inferior local versions). It is specified for 5 inch nominal diameter wells and a maximum recommended lift of Suppliers 45 meters (though in practice it is used for Local pumphead components: There are greater lifts). several manufacturers, including Atlanta The Eureka (also known as the US Vinyl Corporation, 97 9th Avenue, Grace Champion Eureka) cylinder is similar in Park, Caloocan City, Philippines. design to the model with the same name Eureka cylinder: Malanday Machinery & General Description made by Clayton Mark in the USA. The Mfg Corp, Km 15 McArthur Hi-way-A. brass cylinder is available in nominal Banco Street, Dalandaman, Valenzuela, The locally made pumphead (Iph) is used diameters of 2, 2-1/2 and 3 inches. Those Metro Manila, Philippines. in the Philippines with either the locally monitored by the Project had a diameter of Takasago cylinder: Takasago Pump Co made Eureka or the Japanese made 46mm and were designed for installation in Ltd, No. 10-24 Osaki 1 -chome, Shinagawa- Takasago cylinder. The lph can be made a2 inch rising main. ku,Tokyo,Japan. from standard "off-the-shelf" hardware and The bottom of the plunger is tapered plumbing supplies, though an assembly to allow it to be screwed onto a threaded Indicative prices - Apr 1985 drawing and a complete set of parts receiver protruding from the footvalve. except for the wooden handle and grip can The aim is to allow extraction of the Eureka cylinder, including also be provided by local companies or by plunger and footvalve through the open- plunger and footvalve US$ 40 Takasago. topped cylinder without removing the The lph consists of a concrete rising main. A spring "dog" holds the Prices not provided for other components. pedestal, a very long wooden handle, and cylinder in the rising main and it is sealed 134 PUMP 19 Philippines Deepset Field Trials Assessment Test conditions. 'id Test conditions _.- - ,~ u The ratings for the Philippines Number Head Data *' AL Deepset pump are generally of range available - based on the performance of the Country pumps (meters) (months) I Takasago cylinder with a local pumphead. The Eureka cylinder Philippines - cannot be recommended, as its Eureka 62 8-42 24 - performance in laboratory and Takasago 64 1-112 24 f;eid trials revealed design IF_ ~~~~~~~inadequacies and a high - I S frequency of repairs. Discharge Rate For deep settings, the pump Statistical analysis of the field data, been replacement of the plunger seals. achieves a comparatvely high including graphical presentation, was not Data are not conclusive, but it appears discharge and eams a "good' (oo) considered justified, because the data that seal replacement frequency is less rating It cannot easily accom- were incomplete. Factors affecting the than on other pumps, and in other plish the higher discharges lack of data included many repairs which respects too the cylinder can be rated needed for a oo rating at lower were carried out in the field without the highly. lifts, where the rating drops to presence of the Project's Country Moni- In practice, the Takasago footvalve 'adequate" (a). toring Engineer (CME) and without consis- is not extractable after 6-12 months Ease of Maintenance tently informing the Project. The following service, because the leather seals swell Though the concept of a local commentary is based on observations and jam it in position. Also threads on the pumphead and extractable which can be reliably reported. protruding taper corrode. cylinder and footvalve should In most respects, the local The Eureka cylinder has proved makethepumpsuitableforvillage- pumphead performs well. It is well somewhat problematic. Repairs to the level maintenance, practice accepted by users, though it is very pumping element have been required shows that this is not the case. difficult for children to reach the long about twice a year (about 2.5 times per The oo rating for maintenance handle. Parts which require most frequent 1000m3 pumped). Although typically system B at 7m and 12m lifts, replacement are the wooden handle and installed at lesser lifts than the Takasago, drops to o for lifts of 25m and the top guide bushing. Nuts, bolts and where it could be expected to be easier to 45m. fulcrum pins have also required operate and subject to less wear, it has in Reliability occasional replacement. Replacements fact been less intensively used and For low lifts and low discharges, are relatively simple to undertake and required more repairs than the Takasago. the Takasago cylinder and local parts can be obtained locally. The handle Eureka installations have generally pumphead earn a oo rating, but is the most expensive of the commonly served about 15 families per pump, and higher repair frequencies mean a needed spare parts, costing about US$7- pumped about 2.2m3/d (a consumption o rating for 4m3/d output up to 11, depending on the length and local rangeof20to30literspercapitaperday). 25m lift, and the pump is not prices. The large concrete pedestal adds Overall, the Eureka cannot be recommended for higher lifts or to the cost. recommended. The expanded rubber discharges. The Takasago cylinder has perfor- rings jammed in the rising main and made CorrosTon Resistance med well. Units with this cylinder have removal impossible. The design has The pump has no special been intensively used, despite the high lift inherent inadequacies and manufacturing cannot be remcomended for conditions in which many of them have quality control is doubtful. cannon wee recoumnder is been installed. Typically, they have A number of modifications could be situatcons where groundwater is served about 20 families per pump, and instituted to improve the durability of the Abrasion Resistance during the dry season about 4.3m3/d has combined unit, which would also be Use of leather cupseals means a been pumped (with the consumption enhanced by improved manufacturing - rating for abrasion resistance. ranging from 30 to 50 liters per capita. quality control and better installation Manufacturing Needs The most common repair needed has procedures. The pumphead can be manufac- tured locally in most developing countries, earning the pump a o rating for countries with a low industrial base (level 1). Mode- rate industrial development should ensure satisfactory manu- facture of the cylinders, giving a oo rating for levels 2 and 3. PUMP 19 135 The Netherlands Laboratory Tests THE SWN 80 & 81 PUMPS HAVE NOT BEEN TESTED IN THE CATR LABORATORY General Description nylon, and a bi-directional elastomeric Indicative prices - Apr 1985 seal. Valves are brass, with neoprene on __________________ The SWN is a lever-operated reciprocating the sealing faces. Pumprods are encased SWN 80 deepwell pump constructed of fabricated in polyethylene tubing to prevent abrasion with ball bearings US$ 630 steel. It is designed to be fitted with ball of the thick-walled (48/36mm) PVC rising with plastic bearings US$ 609 bearings or polymer journal bearings at the main. In the SWN 81, the PVC cylinder is fulcrum and rod hanger. The manufacturer reinforced with stainless steel bands. SWN 81 suggests that these might also be Conversion units are available to with ball bearings US$ 945 replaced in the field with locally-made make the pump suitable for pressure with plastic bearings US$ 1085 hardwood bearings. discharge to a storage tank, or for use as The SWN 80 is the shallow-lift a suction pump, but these have not been Riser/rod combination version of the pump, with a recommended tested as part of the Project. in 3m lengths US$ 94 maximum lift of 25 meters. The SWN 81 is for deeper lifts (25-50m). It has more Manufacture Cylinders substantial bearing assemblies and is The pumpstand requires steel fabrication, 2 inch diameter US$230 generally a more robust pumphead. An turning and welding, with good quality 2.5 in. diameter US$287 adjustable counterweight handle is used control. For the below-ground assembly a 3.5 in. diameter US$ 336 on the SWN 81 to balance the additional high level of machining skills and quality 4 inch diameter US$575 weight of pumprods at greater depth. control are essential. Below-ground components, which are also used on the Kangaroo pump Suppliers (Pump 30) made by the same company, Van Reekum Materials BV, Kanaal Noord consist of a PVC cylinder, a plunger and 115, Postbus 89, 7300 AB Apeldoorn, The footvalve made from stainless steel and Netherlands. 136 PUMP 20 SWN 80 & 81 Field Trials Assessment Testcodition pS t , t ({,The SWN 80 & 81 ratings are Number Head Dats based on field trials at compara- of range available - ~~~~~~~~~tively shallow depths, but with of range available ~~~~~~~~~enough data available to make Country pumps (meters) (months) confident judgments on the Kenya 8 10-38 24 ~~~~~~~~~~~~~PUMPS likely performance in a Kenya 8 10-38 24 D wide range of conditions. Tanzania 31 1-18 22 di Discharge Rate r _- _ The available choice of cylinder sizes means a 'good (oo) rating for all pumping lifts Though the field trials in Tanzania invol- and rising main into the pumphead. With Ease of Maintenance ved only shallow lifts, the combined data the added weight of downhole components Consideration of maintenance from Kenya and Tanzania provides a good at deeper lifts, the operation would be needs is a major shortcoming of basis for judging the performance of the even more difficult. For maintenance, this pump. The method of SWN 80 & 81. The pump is very easy to when the operation is reversed, the heavy connecting and dismantling the use, with a long pumping handle and the pumphead must be lifted and supported on downhole components to and soft pumping action resulting from plastic a temporary frame while the rising main is from the pumphead precludes rising mains unscrewed. illage-level maintenance at any Initially, several of the Tanzania test The double acting elastomeric seal is lift For lifts of less than 12 pumps suffered rod hanger breakages an outstanding feature of this pump. meters, area mechanic mainten- caused by seizure of the polymer Running in a calibrated uPVC cylinder it ance (system B) is quite feasible, bearings. Increased clearance on the gives exceptional wear resistance, though eaming the pump a oo rating, bushes resolved the problem. In one in time both seal and cylinder will become which drops to 'adequate" (o) at pump installed on a deeper than average worn and require costly replacement. deeperlifts. well (water level about 15 meters) there Corrosion resistance too is excellent, all Reliability were four broken plungers in 14 months the downhole components being made The difficulty of maintenance at due to stress failures. In Kenya, there from resistant materials. higher lifts, combined with the have been several failures of pumprod The availability of different cylinder need for more frequent interven- and rising main threads in the deeper sizes means that high discharges can be tions, makes the pump unsuitable wells, though overall, the pump has achieved at shallow lifts. for 45 meter lifts, or for a daily proved quite reliable. In general, the Project views the output of 8m3/d at 25 meters. The Installation and maintenance are not SWN 80 & 81 as a very promising, though rating is o for lesser daily outputs easy. The pumphead is heavy, which expensive pump, with the major reser- at 25m, and the pump earns a oo adds to the already difficult operation of vation that maintenance needs appear to rating at lower lifts. screwing the pre-assembled pumprods have been neglected in the basic design. Corrosion Resistance The choice of materials for downhole components provides excellent corrosion resistance and earns a oo rating. Abrasion Resistance A good design and choice ot materaias justifies aoo rating. CAUSES OF ESSENTIAL INTERVENTIONS Manufacturing Needs 2- 2.5 -10 The number of skills and the 1.8 TANZANIA degree of quality control needed '^ 1.86TAN~Ia 2 make the pump unsuitable for o 1.4 ffi 3 manufacture in developing count- o t o ries with only low industrial bases a. 1.2 1.5 , (Category 1). It is however quite suitable for manufacture in ttt 0.8 * * 1 tz -4 5 countries with moderately devel- WY La _ , {=oped industry, scoring oo for 0.6- W Categones 2 and 3. - . 0.5 -2 0.2 0 MM0 -- 0 TOTALHD F RH PR RM PS PE FV OT PART REPLACED HD-Handle RH-Rod hanger RM-R.sing main PE-Punp.ng eiement F-Fulcru PR-Pump rod PS-Piston seal FV-Foot valve OT-Other PUMP 20 137 France Laboratory Tests Date tested: 1979 Reported: ODA Report 1981 Performance data (typical values) Head (meters) 7 45 Pumping rate (cycles/min) 36 92 24 75 Volume/min (liters) 10 24 5 14 Input (watts) 59 199 51 245 Mechanical efic4ency (%) 15 14 57 44 Maximum pedal force (kg-f) 47 76 Footvalve leakage (mIl/min) No significant leakage Note: The rubber pumping element has been modified since the laboratory tests, so thatperformance characteristics may now be different Evaluation the pump completed the test without At the time of the laboratory tests in 1979, failure. At the end of the test, there was the Vergnet was a relatively new design. significant leakage past the seals of the The concept has remained essentially the drive plunger, leading to the need to raise same, but detailed design changes have the pedal by hand frequently. The guides taken place since the tests were carried have been modified since the tests and a out, and the laboratory findings should be repriming arrangement has been added to viewed in that light. More recent downhole overcome the pedal return problem. General Description components were tested in 1982 on the Corrosion resistance is generally General Description ABI-ASM pump (Pump 01). good. Some pitting did occur in the end The Verg net is a foot-operated pump Installation of the Vergnet pump is caps of the rubber diaphragm, but again working on hydraulic principles. Twin very simple. No lifting tackle is needed, as the material has subsequently been flexible polyethylene hoses connect the the pumping element can be lowered down changed. above and below ground units - there is the well by hand, using the connecting The pump requires considerable no mechanical link. The pumpstand is mild polyethylene hoses. The pump is not self- effort to operate, but full body weight can steel with stainless steel and brass prim- priming, be applied to the pedal. Users therefore ary drive cylinder components. The below The ground-level primary cylinder is found the pump relatively easy to use, ground pumping element is a stainless also comparatively easy to maintain, though children and smaller users could steel cylinder with valves top and bottom and removal of the pumping element is a not produce the high forces needed for andaflexible rubberdiaphragm inside. simple task, though replacement of the pumping from depth (some overcame the The diaphragm expands in response diaphragm with a new one is expensive. problem by balancing two people on the to internal pressure exerted by the primary The laboratory trials indicated that the small pedal). drive piston in the pumpstand, displacing most likely maintenance needs would be The pumpstand proved robust, and water from the pumping element up the replacement of the pedal rod guides and with only one external fixing seems reaso- delivery pipe. When foot pressure is plunger seals in the primary cylinder, nablyresistanttoabuseorpilferage. removed, the elasticity of the diaphragm every 1500 to 2000 pumping hours. Overall conclusion of the labor- forces water back up the drive hose to lift The 4000 hour endurance test atory trial was that the Vergnet's novel the pedal and draws in water through the was carried out at 40 cycles per minute design should prove reliable for comm- footvalve. with a simulated head of 45 meters. The unity water supply use, though the one-off plunger guide wore badly and was rep- cost of replacing the diaphragm is high. Manufacture laced midway through the test, otherwise The pumpstand requires moderate skills in steel fabrication and fitting, while the pum- ping element demands advanced manufac- turing techniques and high quality control. Suppliers Societe Mengin, Zone Industrielle d'Amilly, 45203 Montargis, France. Indicative prices - Feb 1985 Pumpstand and pumping element US$ 587 Twin hose (oer meter) US$ 2.55 138 PUMP 21 Field Trials Assessment Test conditions The Vergnet ratings are based on Number Head Data its performance in field trials and of range available . , + in laboratory tests carried out in Country pumps (meters) (months) 1979. The below ground compo- nents were also laboratory tested Burkina Faso 35 14-44 26 s -1111 owSin 1982, in connection with testing BurkinaFaso35 14-44 26 ~~~~~~~~~~~~of the Abi-ASM pumps. Mali 25 9-21 27 Discharge Rate Kenya 8 15-50 19 - A The discharge rate achievable The V:rgnet pump haS undergone a - - with acceptable pumping effort is The Vergnet pump has undergone a - . S , = too low to make the pump number of design modifications in the - competitive for low-lift appli- course of the Project tield trials, and deve- e cations, and it is rated "unsui- lopment work is still going on to improve .: -. - table" (-) for pumping lifts of 7 the pump diaphragm (current versions are _ . - and 12 meters. For lifts of 25 and supplied with a three-year guarantee). 3 45 meters , the Vergnet can ach- Pump installation has proved very , - ieve the discharge rates needed easy, with no need for lifting equipment. to earn a o ("adequate") rating. The pump can be extracted from a well _ Ease of Maintenance and re-installed within half an hour. It is Below ground components of the also possible to install two or more pumps Vergnet can be extracted from in a single well, (a 125mm well for two any depth without the need for pumps, or a 150mm well for three or four was well within the capabilities of a local special tools or equipment, and pumps). Only one spanner is needed to caretaker and costs very little. above ground maintenance is service the upper cylinder, and the down- A small amount of corrosion simple. However, for replacement hole pumping element can be inspected occurred on the metal parts of the of the diaphragm, a village care- without difficulty. diaphragm, but in general the Vergnet taker might need the assistance In the West Africa field trials, the proved substantially corrosion resistant. of an area mechanic. The "good" Vergnet proved quite reliable, though it This was not the experience in Kenya (oo) rating for maintenance Sys- was susceptible to solid particles entering however, where the end caps of the tems B and C reduces to o for the pumping element, either through the pumping element suffered severe System A. internal pumping circuit or via the upper corrosion. Pedal breakage was another Reliability cylinder assembly. When the pumping problem in the Kenyan trials, though it Field performance of the Vergnet element fills with sand (or silt or clay), the rarely occurred in the lengthier West earns the pump a oo rating for diaphragm becomes inoperative and African trials. lifts up to 25m and daily outputs finally ruptures if it is not cleaned. A new, The discharge rate of 0.6 to 1.0m3/h up to 4m3 For 45m lifts or for improved diaphragm is being field tested, achieved in West Africa proved discharges of 8m3/d, the rating and in some regions mechanics have acceptable to users, but Kenyan users drops to o. been able to repair ruptured diaphragms. did not like the effort needed to pump from Corrosion Resistance The upper cylinder plunger seals more than 25 meters. The oo rating is based on needed regular replacement, but the task performance in West Africa. Abrasion Resistance CAUSES OF ESSENTIAL INTERVENTIONS The Vergnet is little affected by 2 abrasion, but the possibility of 4 2- _ . -1.75 _4 damage to the diaphragm caused W 1.8 1.50 _3,5 by silt build up in the pumping zl1.6 -~ 1 element reduces the rating to o. a1.4-' -1.25 - 3 Manufacturing Needs -2.5 i The Vergnet pumpstand is ,,> 1.2- -1 i5 .; suitable for manufacture in a o 2 country with moderate industrial 0.8 -0.75 w . facilities, but thedownholecompo- 0 0.8- '5~~~~~~~~~~~~~~~~~ -1.5LJ ~~ 0 . 6~~~~~~~~i I 0.50~~~C nents require specialized skills o5 0'4r 1 -O.S0 - -1 le and tight quality controls and a 0 L- 2- _ -0.25 O. could only be manufactured in a 0.2 - 9~~~~~~~~~~~ -0.5 country with a high level of indus- o- -0 trial development (Category 3). TOT1L PD GB P DH PS PE FV OT The ratings for manufacturing Em BURKINA =MAU PART REPLACED environments 1, 2 and 3 are there- PD-Pedal GB-Gu,de b-sh DH-D-rie/d-scha,ge hose FV-Fool alve fore-, o and o respectively. P-P,sto, PS-P.sto. seal PE-Pumnp,g ele-ent OT-Other PUMP 21 139 Austria __________ Laboratory Tests I 9 c X Date tested: 1982/83 Reported: Handpumps Project Report No.3 Performance data (typical values) - 70mm dia. cylinder 9 l l Head (meters) 7 25 45 Pumping rate (cycles/min) 40 40 40 Volume. min lltersi 28 26 24 Inpul (walls) 62 177 300 Mechanical efficiency (%3 49 59 60 Maximum handle force (kg-f)' 10 30 45 Footvalve leakage (ml/min) No significant leakage I Total watts input is noted. With two operators. input and handle force per person lwill be halt the figures indicated here. Evaluation handle broke once and the cable itself The sample pumps were well packed, finally broke. Modified handles and crank- though unwieldy (4 meters long packing shafts were provided rapidly by the manu- case). They arrived in good condition, but facturer and a swivel was fitted in the the handles of both pumps had been cable. With these modifications (now slightly misaligned in assembly. permanent) the VEW completed the endu- Steel rising main was used in the rance test without further failure, though laboratory tests, as recommended by the at one point the plunger jammed at top manufacturer at that time. Installation dead center and had to be freed by pulling General Description instructions were useful, but would on the cable by hand. At the end of the have benefited from more illustrations. In test, the pumpstand and cylinder were in The VEW is a deepwell force pump with a fact heavy lifting tackle and skilled generally good condition, but with some rotary operating mechanism, using cable people are essential for installation, as play evident in the crankshaft bearing. rather than rods. The pumpstand is made downhole components are heavy and not The plunger seal was excessively worn from varnished steel plate (stainless steel readily manipulated by hand. Pipe and there were signs of wear on the is an optional extra) and ball races are wrenches have to be big enough for 4 inch plunger body. The footvalve was in good used at the crank pin journals. The cable pipe. condition. attaches to an eye on the hanger, and a For maintenance purposes, the cyl- There was little sign of corrosion, large stainless steel counterweight main- inder can be withdrawn using the crank as except for some around the cylinder snap tains the cable tension. Twin handles a windlass. Originally, the manufacturer fitting at the bottom of the rising main. make the pump suitable for two-person did not recommend on-site replacement of The pumpstand withstood the operation, and each has a counterweight. plunger seals, preferring replacement of impact tests without damage. The heavy cylinder can be withdrawn the complete cylinder. More recently the Users found the VEW difficult to through the 4 inch uPVC rising main, which cylinder has been made easier to dis- operate. Most did not have the strength to has stainless steel connectors and can mantle, but seal replacement remains a attain sufficient momentum to keep the also form the well casing. The piston seal skilled operation. If the cable breaks, handle turning smoothly. The modified is PTFE backed by a concealed rubber cylinder extraction is likely to be difficult. handles now used make operation easier, ring, and piston and footvalves use stain- The 4000 hour endurance test and the VEW is well suited to two-person less steel balls. Six cylinder diameters are was carried out at 40 cycles per minute, operation. available to suit different depths. with a simulated head of 45 meters. Four The overall conclusion of the labor- breakdowns in the first 1100 hours could atory trials was that the VEW is a robust Manufacture be attributed to inadequacies in the cable but very expensive pump,. It requires a Both above and below ground components supporting arrangements and the handle lined borehole large enough to take the 4 call for high levels of manufacturing skills and crankshaft arrangement. These resul- inch uPVC rising main, or an appropriate and quality control ted in the cable twisting under tension, snap fixture to be fitted to the bottom of making the bearing saddle run out of true the casing. The pump needs special skills Suppliers and causing rapid wear of the saddle and for installation and maintenance. It is not Vereinigte Edelstahlwerke AG, Franz the crankshaft. suitable for manufacture in developing Josefs-Kai 51, A-1011 Vienna, PO Box The crankshaft wore out twice, the countries. 56, Austria. Indicative prices - Mar 1985 Pumpstand, cable, cylinders, and spares, for 30m lift US$1,400 140 PUMP 22 VEW A18 Field Trials Assessment The VEW ratings are based on performance in the laboratory tests. THE VEW PUMP HAS NOT BEEN FIELD TESTED Discharge Rate BY THE HANDPUMPS PROJECT Though the pump is capable of high discharges at all depths, the difficulty of operation and high efforts needed keep the rating down to `adequate" (o) for all pumping lihs Ease of Maintenance The pump is 'unsuitable" (-) for village-level maintenance (Sys- tem A) and lifting gear would be needed for maintenance at depths of 25 and 45 meters. The pump therefore eams a o rating for area-mechanic maintenance (System B) at depths of 7m and 12m only. Reliability Modifications have corrected the early reliability problems in the laboratory trials, but when mainlenance needs are taken into account. the pump is not rated suitable for discharges greater than 4m3/d or lifts greater than 25 meters. The rating of o for other applications, rises to "good" (oo) for discharges of 1.5m3/d, where maintenance needs would be slight. Corrosion Resistance The pump is manufactured from corrosion resistant materials and eams a oo rating. Abrasion Resistance Rapid wear in the plunger seal when sand was added to the water in ihe endurance lest results in a - rating for abrasion resistance. Manufacturing Needs Well-developed skills and compre- hensive facilities are required for manufacture of the VEW. It could only be manufactured in a developing country with an advanced indusirial base, and then only with some external support and guidance The pump is therefore rated o under manu- facturing environment 3, and- for categories I and 2. PUMP 22 141 The Netherlands, Burkina Faso Laboratory Tests Date tested: 1985 Reported: World Bank Applied Technology Note No. 2 Performance data (typical values) - 50mm dia. cylinder Head (meters) 7 25 45 Stroke (mm) 310 190 140 Pumping rate (cycles/min) 50 52 50 Volume/min (liters) 30 19 11 Input (watts) 78 120 133 Mechanical efficiency (%) 40 63 60 Maximum handle force (kg-f) 10 12 18 Footvalve leakage (mL/min) No significant leakage Note: Figures are fora "flying'start Evaluation gland needed repacking, but otherwise the Three versions of the Volanta have been pumpstand was in good order. tested at different times. This summary is There was no evidence of corro- based on the most recent design, incor- sion at the end of the test. General Description porating stainless steel pumprods with Some users found the Volanta hook-and-eye connectors in place of the difficult to start. and to maintain a steady The Volanta is a deepwell reciprocating previous cable connection between above rhythm, and the delivery is greater when pump driven by rotation of a large fly- and below ground parts. Details of the the pump has a flying start, as it wheel. A crank and connecting rod earlier tests are in Project Report No.3. commonly does during daily use in the convert the rotary motion to a recipro- Following the earlier laboratory trials, field. cating action transmitted to the plunger the manufacturer made a number of After the endurance test, the work through stainless steel pumprods. For changes, settling for the seal-less input per stroke was very much lower, with depths less than 30m, hook-and-eye stainless steel plunger in a fiberglass a corresponding improvement in overall connectors are used to join the pumprods; reinforced plastic cylinder as standard, pumping efficiency. There was no signi- for greater depths, the manufacturer has relocating the taper seat at the top of the ficant change in the plunger or cylinder recently adopted threaded connectors. cylinder to prevent sand-locking, adding dimensions, and the plunger has no seals, The crank throw can be adjusted to suit brass weights to the molded rubber so the lower work input was attributed to water depth. valves, and substituting steel pumprods reduced friction in the wellhead gland. Crankshaft and flywheel run on ball with hook-and-eye connectors for the The body impact test was not bearings mounted on a plate which can be previous cables. applicable to the Volanta, which is fixed to fixed to a steel or concrete pedestal. The Initially, pump performance did not an in-situ pedestal, but in the earlier trials cylinder is a fiberglass reinforced epoxy match the manufacturer's figures and this tests were carried out on the spokes of resin tube with a close-fitting seal-less was found to be due to excessive the wheel, which bent at an impact of 400 stainless steel plunger. Molded rubber clearance between the plunger and the Joules, though the pump remained usable. valves are used and a 0.1mm screen is cylinder. A replacement cylinder produced The overall conclusion of the lab- fitted. The cylinder can be lifted from the improved results. Two pumprod breakages oratory testing was that the Volanta is an well without removing the 75mm diameter occurred during the first half of the innovative design, which is very simple to PVC rising main. endurance tests. The manufacturer install and maintain. The design improve- supplied new rods from a different grade of ments have been successful in improving Manufacture stainless steel for the remainder of the the performance, reliability, and service- The above-ground components of the endurance tests and no further failures abilityofthepump. Volanta are comparatively straightforward occurred. Many parts are suitable for to manufacture. The fiberglass reinforced In the final inspection, the valves manufacture in developing countries, plastic cylinder and stainless steel showed some signs of wear but were still though rigorous quality control is needed plunger must be manufactured to fine serviceable and the cylinder and footvalve in manufacture of the cylinder assembly. tolerances. were in good condition. The pumpstand Suppliers Jensen Venneboer BV, Industrieweg 4, Postbus 12, 8130 AA Wijhe, The Nether- lands. Centre Sainte Famille, Saaba, BP 3905, Indicative prices - Mar 1985 Ouagadougou, Burkina Faso. (Inter- national orders can be supplied via STAR, Per pump US$ 600-630 BP 4387, Ouagadougou, Burkina Faso. 142 PUMP 23 Volanta Field Trials Assessment Test conditions /\1 Test________________ _ condiions_ The Volanta ratings are based on Number Head Data tfS . .tt- < a the pump's performance in both of range available f fieldtralsand laboratorytests. Country pumps (meters) (months) I Discharge Rat Country pumps (meters) (months) The adjustable stroke enables the Burkina Faso50 16-31 36 _ _- J-f; I o t , pump to deliver a high discharge at all lifts, and it earns a "good" Ghana 24 6-14 15 * (oo) rating under this heading in Kenya 9 12-45 12 all the tables. Ease of Maintenance 0.3 breakdowns per pump per year and a Most maintenance operations on The pumps initially installed in Burkina similar number of interventions to correct the Volanta can be readily carried Faso were of the old design, using a cable poor performance. Both figures are very out by village caretakers over the as the connection between the plunger similar to the record of the India Mark II in full depth range, but the need for and the head assembly and threaded West Africa. some help from area mechanics joints for the PVC rising mains. The cables The Volanta has also been well for special repairs reduce the frequently caused poor performance and accepted by the users in northern Ghana. rating to "adequate" (o) under were eventually replaced with the new None of the 24 pumps monitored there maintenance system A from 00 arrangement of stainless steel pumprods. required any maintenance intervention undersystems Band C. Cracks and joint failures occurred in the during the first 15 months of operation. Reliability rising mains until a solvent cement jointing Though the pumping lift is only 6-14 Performance in the field trials system was introduced. meters, they are heavily used. From earns the Volanta a oo rating for Except for these early failures, the March to September 1986, daily outputs reliability for depths down to 30 Volanta proved very reliable, though ranged from 2.2 to 18.7m3, with an meters, but reservations about differing qualities of stainless steel can average of 7.7m3, and in the dry season pumprod performance below that still lead to some rod failures (the softer some pumps reached an output of 25m3/d. depth mean a o rating for the 45m steel is more satisfactory). The Volanta pumps tested in Ghana lift. The Volanta's above-ground assem- are of a later model (1984), while those in Corrosion Resistance bly is robust, and in Burkina Faso it has Burkina Faso are older pumps which have The Volanta is built entirely from been found that the rotary action is well been modified during the field trial. corrosion reistant materials below suited to mechanical operation, using a The Volanta has been designed on groundandearnsaoorating. small engine. User reaction to the rotating VLOM principles with emphasis on ease Abrasion Resistance flywheel has generally been good, and the of repair. Only simple tools are needed to The pump has a seal-less piston output, averaging 0.8 to 1.5m3/h has pull out the entire pumping element, and was unaffected by sand proved adequate forthe field trial users. including pumprods and footvalve. The pumping in the field trials, earning The apparently high number of pump- fact that the pump is manufactured in a oo rating for abrasion resis- rod failures on the bar chart is largely Burkina Faso, in a workshop without any tance. accounted for by the early experiences sophisticated equipment (a Catholic Manufacturing Needs with steel cables and rods. More recently, Mission near Ouagadougou), verifies its Most of the pump components are the Volantas have been averaging about suitability for local manufacture. suitable for manufacture in deve- loping countries with a moderate industrial base (manufacturing CAUSES OF ESSENTIAL INTERVENTIONS environments 2 and 3), though CAUSES OF ESSENTIAL INTERVENTIONS good quality control is needed in As 2- _25 - manufacture of the fiberglass - 1.8 2 ' 44 reinforced plastic cylinder and z 1.6 Z - stainless steel plunger. External -17 3.5~ 1.4- .g help would be needed if attempts m1.50 a 3 were made to make the Volanta in 1.2- 1.25 -2.5 a country with only a low or g - Q moderate level of industrial o 0.8 11 1 -2 8 development (manufacturing envi- 0 6 ll 0.75 -1.5 ronments 1 and 2). The ratings 0.- *L * t Wr under categories 1,2 and 3 are tic 0.4- -0.50 C 1 Cctherefore o, o and oo respec- 0.2 n0.25 -0.5 tively. o _ a ' l'. , 0 -0 TOTAL HD F RH PR RM PS PE FV OT PART REPLACED e BURKINA I = BURKINA 11 HD-Handle RH-Rod hanger RM-Rising main PE-Pumping element F-Fulcrum PR-Pump rod PS-Piston seal FV-Foot valve OT-Other PUMP 23 143 United Kingdom Laboratory Tests Date tested: Full test in 1980; extra tests on modified below-ground components in 1983 Reported: ODA Report 1981 on 1980 testing. Performance data (typical values) - 63mm cylinder, 1983 Head (meters) 7 25 45 Pumping rate (cycles/min) 40 40 40 Volume/min (liters) 14 14 14 Input (watts) 29 79 135 Mechanical efficiency (%) 54 68 72 Maximum handle force (kg-f) 4 10 18 Footvalve leakage (ml/min) No significant leakage Note: These results obtained after bedding in the pump for 190 hours. Initially, the pump was stiff to operate because the piston seals were oversized. Evaluation The pumps tested in 1980 were packed in version was not endurance tested. heavy-duty corrugated cardboard cases, The 1983 version was subjected to locally reinforced with wood, and were impact tests. The handle was distorted, General Description received in working order. In one of the though this did not affect the operation of samples tested in 1983, however, the the pump. The baseplate was also The Consallen is a deep-well, lever-arm brass bush inserted in one of the handle distorted by a heavy impact on the body of force pump. Pumpstand and handle are bearings was too long, so that the handle the pumpstand. Although the construc- fabricated from steel and hot-dip galvan- could not be assembled into the pump- tion of the pumpstand should prevent any ized. Handle bearings are sealed ball stand. The threads on the pumprods were loss of sanitary seal at the wellhead, such races. The rising main is attached to a not straight, due to a fault which the distortion would be likely to impose removable delivery tray, making it poss- manufacturer corrected immediately. additional bending loads on the pumprod ible to extract the below-ground assembly Helpful and comprehensive instruc- and rising main. The pump withstood the without removing the pumpstand. tions for installation, maintenance and allotted 96,000 cycles of the handle shock The rising main is ABS pipe and repair were provided, in English. Using test without failure. Users found the pump pumprods are stainless steel with rolled ABS rising main, the pump is relatively generally easy to operate. threads. The cylinder barrel is internally easy to install without lifting tackle. The overall conclusion of the lab- honed stainless steel tube. The brass General maintenance is also oratory tests was that the pump has the plunger is fitted with a hydraulic poly- straightforward, though repairs to the potential to be suitable for community urethane U-seal. The footvalve varies with steelwork of the pumpstand would be water supply, if adequate reliability in the different cylinders using either a molded difficult to carry out in the field, and care is field can be assured. A number of modifi- rubber membrane or a rubber 0-ring seal. needed when the handle bearings are cations have been introduced since 1980, Manufacture replaced. though there remains scope for further The pumpstand requires machining and In the 4000 hour endurance test, improvement. The light weight of the welding of steel sheet and section. carried out on the 1980 version, the pump below-ground assembly, using ABS pipe, Processes are straightforward, but high was driven at 40 cycles per minute, with a assists in both installation and mainten- standards of workmanship and quality simulated head of 45 meters. No break- ance. However, the materials and control are necessary. Similar require- downs were recorded. In the final inspec- methods of construction mean that the ments apply to the below-ground assem- tion, the pump was found to be in good pump would not be easy to manufacture in bly, particularly to achieve an appropriate working order throughout, with little wear. mostdeveloping countries. internal finish in the cylinder bore. There was no corrosion. The 1983 Suppliers Consallen Structures Ltd., Epping, Essex, UK. Indicative prices - Feb 1985 Pumpstand and cylinder US$ 132 Stainless steel pump rod, per meter US$ 3 ABS rising main, per meter US$ 3.50 144 PUMP 24 Consallen Field Trials Assessment Test conditions ________________;__________ _ ~ .The Consallen ratings are based Number Head Data on the pump's performance in of range available . . F X s i lengthy field trials in Malawi and Country pumps (meters) (months) b on laboratory testing. Modifi- cations made to the pump design Malawi 16 8-25 31 '- ^as a result of early trial results have been taken into account .___________________________________ - ~ where possible in the ratings Because of the Project judgment The lengthy field trial in Malawi has that the pump cannot be recom- provided good data on the performance of about using the Consallen. Consallen mended for deep lifts, it has been the Consallen pump. Generally, the pumps pumps, which were breaking every 2-3 included in Pump Selection have performed poorly. The most signi- months were eventually replaced with Tables for lifts up to 25 meters ficant problem was the failure of ABS either Maldev (Pump 14) or India Mark II only, though manufacturer's liter- rising mains at the threaded joints. It is (Pump 09) pumps, which would last for 1-2 ature indicates greater lifts. thought that the problem was aggravated years between repairs. Discharge Rate in many cases by oversized polyurethane Installation of the Consallen is a Winh the right choice of cylinder seals supplied with the cylinders. After the fairly simple operation, helped by the light size, the pump can achieve high seals had been filed down by the weight of the downhole components, dischargtes and eal s a igood manufacturer, fewer breakdowns occur- though some skill is needed. Maintenance Ease of Maintenance red, though some were still recorded. too is comparatively easy, unless the The skills and tools needed Several pumpheads suffered severe breakdown is major (as with the broken preclude village-ievel mainten- damage, with the handle fulcrum bracket fulcrum brackets). ance thelcmarate shearing off the pumpstand, because of The overall conclusion of the field simplicity of most maintenance the weak nature of the flange and its con- tests was that use of the 1983 Consallen earn the pump a oo raling for area- nection tothe square-section pumpstand. should be restricted to lifts of 10 meters or mechanicorceniral maintenance. As field trials progressed, the less, when it can be expected to have reas- Reliability manufacturer was kept informed of the onable reliability and be straight-forward to The frequency of breakdown problems. As a consequence, stiffened maintain. For greater lifts, frequent break- results in the pump being rated pumpheads were delivered and replaced downs can be expected, and the pump "unsuitable' (-) for use at 25 the earlier ones. The modified pumps also cannot therefore be recommended for meters lift. It is rated 'adequate" incorporated a delivery tray which allows village use (though it has been advertised (o) for daily outputs up to 4m3/d at removal of the downhole components as suitable for lifts down to 60 meters). 12m lift or 8m3/d at 7m lift. and through a cover plate on the pumpstand. Used for low lifts, the pump has the earns a oo rating for lighter Most of the Malawi pumps were advantages of good abrasion and corr- duties. equipped with 2-inch cylinders, giving osion resistance. Corrosion Resistance relatively low discharge. The combination Design changes have been made, All components are corrosion of low discharge and frequent breakdown but the midified pumps have not been resistant, giving aoo rating. meant that users were not enthusiastic tested. Abrasion Resistance The polished cylinder and polyur- ethane seals earn a o rating. CAUSES OF ESSENTIAL INTERVENTIONS Manufacturing Needs __________________________________ Though the Consallen's basic 10- 12 -25 assembly s not complex, it needs 9- careful quality control in manufac- 8- -10 -20 Y ture, and uses ABS rising main o7 fl twhich may not be readily available o -8 in many developing countries. S, 6- *El -15 X Ratings for high. moderate and 9 5 - 6 low levels of industrial develop- Eli 4 - at *r 10 ment are therefore oo, o, and- ,e 3- W * -4 C t respectively. a- if 2 - * * r -~~~~~~~~~~~- 5E 0 0 _0 TOTALHD F RH PR RM PS PE FV OT PART REPLACED HO-Handle RH-Rod hanger AM-Rising main PE-P.mping element F-Fulcrum PR-Pump rod PS-Piston seal Fv-Foot vaive OT-Other PUMP 24 145 Thailand Laboratory Tests THE DMR (DEMPSTER DERIVATIVE) HAS NOT BEEN TESTED IN THE CATR LABORATORY General Description The original Dempster pump was designed in the USA in the last century, as a family pump used normally in a farmyard. The DMR uses a similar design. Most parts of the pumphead and working mechanism are made from cast iron, with steel used for the top guide flat bar, connecting rod and pivot pins. The many exposed moving parts need heavy lubrication. Below ground, the pump is of conventional reciprocating design, using galvanized steel rising main, steel pumprods and a 3-inch diameter brass cylinder with traditional leather cupseals. Manufacture In Thailand, fairly complicated sand casting is used to manufacture the pump. Machine finishing is necessary for some above-ground components and many below-ground ones, notably the cylinder and pumping element assembly. Suppliers There are several manufacturers in Thailand, including Muangthong Charkkol Co. Ltd, 363/2 Takisin Road, Bangkok 10600, Thailand. Indicative prices - May 1985 Pumpstand and cylinder US$93.50 Pumprods and rising main per meter US$2.60 146 PUMP 25 DMR (Dempster derivative) Field Trials Assessment Test conditions .__________________________ _ -.The ratings for the DMR Dempster Number Head Data n - s _ derivative are based on the of ra available pump's performance in field trals of range ailbeover a limited depth range Country pumps (meters) (months) Discharge Rate Thailand 35 3-21 21 ~~~~~~~~~~ ~~ . . ~~Availability of a range at cylinder Thailand 35 3-21 21 -:"' ' sizes means that the pump can achieve a "good' (oo) discharge for all heads up to 25m. The DMR Dempster derivative did not per- - - Ease of Maintenance form well in the field trials. The pump was , > - The pump is not suitable for heavy to operate with the original mech- =vilage-level maintenance, but at anical advantage of 5:1. Extension of the shallow aeles can be readily main- handle, to increase the mechanical advan- shalwtained by area mechanics. It tage to 8:1 did not prove successful, as . - therefore earns a oo rating for the handles were not strong enough to , D;f maintenance system B at 7m and withstand the extra strain then imposed. 12m, reducing to "adequate" (o) at A good discharge rate can be ach- .. 25m. ieved by those able to use the full stroke Reliability length (215mm), but the.long pump body F - . - Performance in the field trials makes the handle too high for young showed that the DMR Dempster children. The drive mechanism is shaky The below ground components of the derivative would require an and the exposed moving parts need DMR Dempster derivative are conventional unacceptable level of repair if continual heavy lubrication to avoid rapid and required the usual repairs to worn used for lifts in excess of 12 wear. Even with lubrication there are prob- leather cupseals, footvalves and leaking meters. At shallower lifts, the lems, as the grease combining with dust joints. The threaded connection between pump is rated oo for low daily and sand in the air causes grinding of the pump body and the 1-1/2 inch diameter outputs and o for moderate daily several moving parts. galvanized steel rising main proved outputs (4m3/d), but unsuitable The most common failure in the field especially prone to fatigue failure. for higheroutputs. was breakage of the fulcrum link, with As a result of the field trials, it was Corrosion Resistance other failures including wear of the flat bar recommended that DMR Dempster The pump has no special to connecting rod thread, pumprod break- derivative pumpheads in Thailand's rural protection against corrosion and age at the connecting rod adaptor, broken water programme should be replaced with cannot be recommended for handles, and failure of the pump base Korats (Pump 13), leaving the downhole situations where groundwater is flange weld. components in place. Abrasion Resistnce Use of leather cupseals means a - rating for abrasion resistance Manufacturing Needs The Dempster design has been adapted to make the pump suit- able for manufacture in ThailandJ. CAUSES OF ESSENTIAL INTERVENTIONS and it could be readily made in a country with a moderately 5 1.75 -20 developed industrial base, 4.5- -1.50 -18 earning a oo rating for manu- 4 . 16 facturing categories 2 and 3. °0 3.5- 1.25 -14 00 @3 1 -12 ° 0 2.5 5 -10 0.75 ,-8 1.5 60.50 10.25 4 0.5 _ 02 0- 0 0 TOTAL HD F RH PR Ri PS PE FV OT PART REPLACED HD-Handle RH-Rod hanger RM-R..ing nain PE-P.mp,ng element F-Fulcrum PR-Pump rod PS-Piston seal FV-Foot valve OT-Otner PUMP 25 147 Finland Laboratory Tests Date tested: 1982 Reported: Handpumps Project Report No 3 Performance data (typical values) - 76mm dia cylinder Head (meters) 7 25 Pumping rate (cycles/min) 40 40 Volume/min (liters) 25 26 Input (watts) 39 139 Mechanical efficiency (%) 71 75 Maximum handle force (kg-f) 8 34 Footvalve leakage (mlmin) No significant leakage A/Li Evaluation greater depths. At the end of the test, the , The two test pumps, including the handle bearings, plunger seal, cylinder | e:> ii pumprods and rising main, were delivered and valves were in good condition. in a single wooden case. The case was Corrosion caused the pump to fail m ~~~~~~~~~large and very heavy. Both pumps were in after 1000 hours. The setscrews used to working order, but one cylinder had been assemble the plunger were badly corr- General Description damaged causing distortion of the bore. oded, and one of them broke. The plunger A leaflet was supplied with the pumps could not be dismantled and was therefore The Nira AF76 is a deep-well, lever-arm which included an annotated sketch of the replaced. The setscrews in the second force pump. The pumpstand has a components, but there were no instruc- plunger corroded in the same way as galvanized tubular steel column with a tions for installation or maintenance. those of the first, but less rapidly, so the cast iron base and pumphead which is Installation is straightforward, but the second plunger completed the remainder nylon coated. The seamless thin-walled below-ground assembly is heavy, deman- of the test without failure. There was no brass cylinder has a gunmetal plunger and ding lifting tackle for all but the shallowest corrosion elsewhere in the pump. molded rubber cupseal and valve bobbins. settings. Care is needed to avoid dama- The pump was undamaged by Cylinders are available in 50mm and ging the relatively thin cylinder barrel. impacts on the handle, but a heavy 76mm diameters. Maintenance of the cylinder will impact on the pumpstand body broke the also require lifting tackle, since the cast iron baseplate. However, the cast Manufacture pumphead and entire below-ground assem- iron baseplate has been superseded by a Foundry work and steel fabrication skills bly must be lifted out. To service the plun- fabricated, all-steel version. Fitted with a are needed, together with facilities for ger or footvalve, manufacturers spares handle constructed in the laboratory, the rubber molding. are required. The pumpstand is easy to pump completed the allotted 96,000 dismantle. Handle bearings would be cycles of the handle shock test without Suppliers simple to replace in a workshop; in the failure. Vammalan Konepaja Inc, 38200 Vammala, field, replacement of the complete fulcrum Many users found the high levels of Finland. casting might be required. effort required to operate the pump For the 4000 hour endurance test, difficult to apply. Children in particular Indicative prices - Feb 1985 the pump was driven at 40 cycles per found it difficult to bring their weight to minute, at a simulated head of 36 meters. bear on the handle at the start of the down- Pumpstand and cylinder US$ 236 This was the maximum depth recomm- stroke. Rising main and pumprod ended by the manufacturer at the start of The overall conclusion of the per meter US$ 11 the test. The handle broke several times laboratory tests was that the AF76 was during the test, and in response the manu- not a VLOM pump, but relatively small facturer reduced the maximum recomm- design changes could make it suitable for ended depth for the 76 mm cylinder to 18 community water supply, although the meters, and offered a 50 mm cylinder for range of working depths is limited. 148 PUMP 26 Nira AF76 Field Trials Assessment Test conditions Test______conditions___________ The Nira AF76 ratings are based Number Head Data ' - on monitoring of large numbers of of range available 41'-, pumps in lengthy field trials and Country pumps (meters) (months) on laboratory tests, giving a basis for confideni judgmenis Kenya 3 6-25 12 Discharge Rate Tanzania 89 6-25 35 ffi >-8 ,il Cylinder options available give Tanzania 89 1-10 35 d R i the pump a 'good" (oo) rating for -3t 1> all heads (7-25 meters). Ease of Maintenance A large sample of pumps have been on Though the tools and skills test over a long period in Tanzania on a Field maintenance was simple in the needed preclude village-level project where a total of some 2000 pumps shallow settings used in Tanzania, maintenance of the Nlra AF7S, are installed. Comparative data is there- because the complete pumphead, the comparalwe ease of the fore extensive, though average pumping together with rising main and pumprods, operation at shallow depths earns heads are extremely low, so few break- could be pulled out in one piece. the pump a oo rating for area- downs might be expected and few Nevertheless, a substantial tool kit is mechanic maintenance at 7m and occurred. required, and at greater depths (beyond 12m, falling to "adequate" (o) at A serious design flaw with this pump about 6-8 meters) the pump is more 25m. is that the single major wearing comp- difficulttomaintain. Reliability onent, which is the brass fulcrum unit Wear on the fulcrum "lever" can result Combining the anticipated break- (referred to as "the lever") is a very in impact damage to the cast iron pump- down frequency with the repair expensive spare part (in the region of head, caused by endplay in the handle. skills needed, the pump's US$50). The elastomeric seal in the brass reliability is less than adequate The pump proved relatively popular. cylinder gives good abrasion resistance, (- at 25 meters tallft or for high It lifts substantial quantities of water with but corrosion would be a problem in rateso fora daily outputsof 4mlid its short handle and low mechanical aggressive groundwater, because of the at 7 or 12m lift and oo for 1.5m3/d advantage acting on a 76mm cylinder. use of steel rising main. at the same lifts. Corrosion Resistance Corrosion occurred in the laboratory tests, and the pump has no special protection against corrosion. tt cannot therefore be recommended where groundwater will be corrosive. Abrasion Resistance The pump earns a o rating for abrasion resistance, with the cautionary note that the soft brass cylinder lining does abrade slowly and may be costly to CAUSES OF ESSENTIAL INTERVENTIONS replace when the limit is reached. 1 1.25 7Manufacturing Needs The need for good quality casting 0.9 TANZANIA -6 u of brass and cast iron comp- 0 o.8 1 x onents means that the pump is gi 0.75 -5 unsuitable for manufacture in 0 0 o countries with a low level of X 0.6 0.75 - X industrial development (Category ! 0.5- C 1). It requires no exotic materials E 0.4 0.50kS -3 and could be readily manufac- 0.: - . Wtured in developing countries with C0.3 0.25 -2 moderate industrial bases. t 0.2- O0.25t t scoring oo for Categories 2 and 3. 0.11 1 IL TOTALNH FH RH PR RM PS PE FV OT PART RE6PLACE,D HD-Handle RH-Rod hanger RM-Rising -nai PE-Pun,ping element F-F.lcrnum PR-Pump rod PS-Piston seal FV-Foot valve OT-Other PUMP 26 149 Zimbabwe, Malawi, Papua New Guinea Handle/spout_ Laboratory Tests THE BLAIR PUMP HAS NOT BEEN TESTED IN THE CATR LABORATORY General Description The Blair pump is an innovative direct action design developed by the Blair Res- earch Laboratory of Zimbabwe's Ministry of Health. It is manufactured in Zimbabwe, and modified versions are being made in Malawi (known as the Madzi pump) and in Papua New Guinea. Prototypes have also been made in the Philippines. All above ground parts are made from steel and below ground parts in plastic. The Blair is different from other direct action pumps in that the rising main also serves as the pumprod, with water dis- charging from the "walking stick" handle. Because the pumprod is always full of water, it returns under gravity, in contrast to the low-mass high-displacement rods used on other direct action pumps, which require a positive downstroke. It is possible to connect rubber hosing to the outlet and thus lift water to an overhead tank. Manufacture As the pump consists primarily of standard pipe and fittings, it is well suited for manufacture in any country with experience in working with PVC. Suppliers Indicative prices - Mar 1985 Proderite (Pvt) Ltd, 21 Leyland Road, Pump for 7m depth US$1145 Ardbennie Industrial Sites, PO Box 2887, Pumprod and rising main Harare, Zimbabwe. permeter US$ 7.60 Pipe Extruders Ltd, PO Box 30041 Lilongwe 3, Malawi. FOB less 13% for export (Proderite) 150 PUMP 27 Blair Field Trials Assessment Test conditions M Test_______conditions ____________ The Blair pump ratings have been Number Head Data based on widespread and varied of range available field trials, which provide a good Country pumps (meters) (months) . level of confidence in the judgments made. The direct Malawi 10 2-10 36 ~ action operation of the pump Malawi 10 2-10 36 i i seI restricts its use to lifts not Tanzania 20 1-5 6 exceeeding 12-15 meters. Sudan 5 3-7 30 - Discharge Rate Philippines 5 N.A. N.A. In comparison with other low-lift pumps, the Blair has a low Papua New from Australian manufacturers. discharge, because of the small Guinea 45 N.A. 20 Most breakdowns which have plungersize. Its rating at 7and 12 Kenya 1 7 28 occurred have been at the connection meters lift is adequate' (O). between the plastic rising main and the Ease oflMaintenance The Blair pump obtained mixed results in steel "walking stick"handle. The pump is extremely simple to the field trials, which covered a wide range The pump is very easy to install and service and must be regarded as of operating conditions, and, particularly, to maintain. It is possible to remove, repair a true VLOM pump, earning a intensity of use. In heavy use in Sudan, and replace the complete installation in 'good" (oo) rating for all possible two out of five pumps broke down during only half an hour, with no lifting equipment maintenance systems. the first six months, and in Tanzania, 8 out and minimal tools. Reliability of 11 suffered the same fate. The pump has not been popular with The ease of repair combined with In Malawi, where user group sizes users who have experience of other breakdown frequencies under are smaller (about 125 users per pump), handpumps, partly because of the low different operating conditions the failure rate was about one breakdown discharge and partly because of the gives the pump a oo reliability per pump per year, while in Papua New difficulty of directing the flow from the rating for a daily output of 1.5m3/d Guinea, where the pumps serve only a few moving spout into narrow-necked con- at 7 meters lift and at 12 meters people and are used for only short periods tainers. lift. The rating drops for heavier each day, no breakdowns were experi- The innovative Blair design has many duty applications, and the pump enced in the first 20 months of testing. It merits, notably its simplicity and corrosion is not recommended for daily is important to recognize that in PNG, the resistance. The seal-less plunger also has outputs as high as 8m3/d. locally modified Blair pump is assembled advantages, including giving the pump a Corrosion Resistance from high quality PVC pipes and fittings reasonable abrasion resistance. Use of PVC pipe and fittings below ground earns a oo rating for corrosion resistance. Abrasion Resistance The seal-less design gives adequate abrasion resistance, though sand would score the cylinder wall. Manufacturing Needs The Blair pump is very easy to assemble and parts are relatively CAUSES OF ESSENTIAL INTERVENTIONS simple to manufacture. The rating 2- 1.6 -10 of oo for manufacture in count- 1.8- MALAWI -1.4 ries with moderate or high levels 1.6- 8 t of industrial development (Categ- -1.2 M odes 2 and 3), reduces to o in 'o 1.4- 1 those with only low industrial S_ 1.2- _ 9 -6 c bases, because of the 0.8 dependence on good quality PVC, sL 0.8 {.eL 4 to assure pump reliability. 0.6- 0. C 0.4 0.4- 2C 0.2 00.2 O- W. _, , _ w, . -O0 -0 TOTAL HD F RH PR RU PS PE FV OT PART REPLACED HD-Hrndlu RH-Rod harger RM-Rising m,ain PE-Punmping element F-Fuicrum PR-Pump rod PS-Piston seal FV-Foot salve OT-Other PUMP 27 151 Ethiopia Laboratory Tests Date tested: Full test 1983; additional /tests oncurrent design 1986. hour intermediate inspections. Progres- Reported: HandpumpsProjectReport sive loss of cylinder performance was ReNo.3 observed, with the most pronounced loss in the final stage of the test, for which sand was added to the water. At the end of the endurance test, the rate of delivery was about 50% of that obtained in the Performance data original performance test. (typical values) In the final inspection, most parts of the piston and foot valve were worn, with Head (meters) 7 corresponding wear on the bore of the Pumping rate rising main. Many particles of sand were (cycles/min) 40 embedded in the HDPE piston. Volume/min (iiters) 28 Corrosion was observed in ferrous Input (watts) 89 parts of both the piston and foot valve. Mechanical efficiency (%/6) 35 Successively more severe impacts Maximum handle on the body of the 1983 pumpstand prod- force (kg-f) 40 uced progressive distortion of the base- Leakageof foot plate. The pump completed the allotted valve (mI/min) 0.8 96,000 cycles of the handle shock test ____vaive____(ml/min) _____ 0.8__ without failure. GeneralDescrip nFiguresarelforthe1986version to Users found the pump very difficult of the 50mm cylinder. pipe for the pump rods, but these were not The Ethiopia BP50 is a shallow lift direct sealed and there was therefore no contri- action pump. In 1981, the pump used bution from buoyancy. In the current standard uPVC pipe for rising main and Evaluation design, the rods are solid steel, so that a pump rod, and was originally intended for The pumps were supplied in a wooden lifting force of about 40kgf is required, lifts of up to 12 meters. The plunger had case, and arrived in good working order. even at only 7 meters lift. The pump is no flexible seal; it consisted of a machined A technical report and engineering therefore much more difficult to operate block of HDPE, with circumferential drawings were provided with the pumps than other direct action pumps which use grooves on the outer surface acting as supplied for testing in 1983. The report, in lightweight, high displacement pump rods. simple labyrinth seals. The pump rods, English, was informative and the drawings The overall conclusion of the though hollow, were not sealed. were helpful for installation. However, it laboratory tests in 1983 was that the BP50 Recently, it has not been possible to is not clear what information is normally represented a simple design with potential obtain suitable materials in Ethiopia. The provided for installations in the field. for VLOM. However, it has not been current design retains uPVC pipe as the Maintenance of the 1983 version of possible to develop many of the original cylinder barrel, but the rising main is the pump was particularly straighfforward. concepts because suitable materials are galvanized steel and the pumprod is solid The plunger could be extracted by simply not available in Ethiopia, and in its current steel. The plunger is conventional, cast in removing the guide bush in the pumpstand form the BP50 has steel pump rods and a gunmetal, with a leather cup seal. and pulling out the pump rods. In the conventional, sealed plunger with a current version, this is more difficult. leather seal. This has further increased Manufacture Since the pump is suitable only for shallow the required lifting force, with the effect of The Ethiopia BP50 has been designed for settings, this should not prove difficult. limiting the maximum practical lift to about manufacture in a developing country. The 4000 hour endurance test was 5 meters. Lightweight, high displacement Basic facilities and skills in steel fabri- carried out in 1983 with the pump driven at pump rods could provide a more favour- cation will be sufficient for the manufac- 40 cycles per minute at a head of 7 able distribution of the required operating ture of the pumpstand. In 1981, only meters. The pump completed the test with effort between the upward and downward simple machining skills were required to no failures, but wear in the plunger tended parts of the pumping cycle, and this is a manufacture the below-ground parts. In to increase the end float of the center bolt, development which should be encou- its current form, however, a foundry is and remedial action was taken at the 1000 raged. required to cast the gunmetal plunger, together with basic machining skills to complete the plunger and foot valve. Suppliers Ethiopia Water Works Construction Authority, Addis Ababa, Ethiopia. Prices not available 152 PUMP 28 Ethiopia BP50 Field Trials Assessment In the absence of leld trials, the ' ^' th1 'Wt ~~~~~Elhiopia BP50 ratings are based on the pump's performance in the laboratory tests and on the judgmeni and experience of Project statf Though, as a direct action pump, the BP50 is grouped in the 0-12 meter range, the high operating force restricts its use to low lifts, and it is therefore rated only for a maximum lift of7m. Discharge rate At the recommended low lifts, the pump achieves a high discharge and earns a "good" (oo) rating. Ease of Maintenance In the current version of the THE ETHIOPIA BP50 PUMP WAS NOT FIELD TESTED BY pump, the complete downhole THE HANDPUMPS PROJECT assembly must be removed to service the plunger or footvalve. While this is reialively easy to achieve at low lifts I means that the oo rating for maintenance systems B and C reduces to "adequate' (o) for maintenance system A (village-level). Reliability The pump is well suited for light use, but would require relatively frequent interventions at higher discharges, and eams only a o rating for daily outputs of 4 and 8m3/d. Corrosion Resistance Tne uPVC cylinder barrel is corro- sion resistant, but use of steel pumprods and galvanized steel rising main reduces the rating to 0. Abrasion Resistance Use of leather cupseals means that the pump cannot be recomm- ended for use in sand-laden water. Manufacturing Needs The need for foundry facilities and machining skills in the manufac- ture of the current model leads to a o rating for countries with a low- level industrial base (Category 1). For moderate and high levels of industrial development, the pump is well suited for local manufac- ture. PUMP 28 153 Malaysia Laboratory Tests . 9 gS w 1S Date tested: 1986 In consultation with IDRC and the Reported: Reportnotyetpublished University of Malaysia, the components of the handle fulcrum and the upper pumprod Performance data were replaced. An additional wooden plate (typical values) was fitted, thereby improving the guidance ._____._____._____:_________ of the upper pumprod, the brass pins in Head (meters) 7 12 the connecting rod were replaced with Pumping rate steel bolts, and a Tara-type (Pump 33) up- (cycles/min) 40 41 per pumprod connector was fitted in place Volume/min (liters) 26 25 of the original joint secured by brass pins. x * i , Input (watts) 83 144 A crack developed in the rising main k, F S lMechanical efficiency (%)36 33 within the pumpstand, originating at the Maximum handle welded connection to the spout. A number forookg-f) 1 1 24 of suggestions were made either to elimi- force (kakageof)oot 11 24 nate the fabricated spout connection, or Leakage of foot to re-position the rising main support so valve (ml/min) 0.5 1.0 that this part of the pipe would not be subject to tensile stress. At the end of the test the plunger, the seals and the cylinder were badly worn, General Description Evaluation and the rate of delivery from the pump was The two test pumps were securely packed substantially reduced as a result. There The IDRC-UM is a shallow lift lever-arm in a wooden packing case, and arrived in was no significant corrosion, however. force pump designed at the University of good condition. However, in both samples In the impact tests, the pumpstand Malaya. It is manufactured in Malaysia the spout tended to leak at the joint with body proved to be robust but the wooden with support from the International Devel- the rising main, and the steel tube at the handle links cracked. However, the pump opment Research Center of Canada, It is top of the pumprod tended to jam in the completed the allotted 96,000 cycles of also available as a suction pump. wooden plate at the top of the pumpstand the handle shock test without failure. The pumpstand casing is steel. Inter- until lubricated with water. Rising main Many of the younger users desc- nal components and the spout are uPVC. and pumprodswere not supplied. ribed the pump as awkward to use, and The wooden handle pivots on wooden links A manual was supplied with the test some found it difficult to apply the neces- fitted with brass bushes. samples, covering both installation and sary force on the down-stroke. Both Rising main and pumprod are stan- maintenance, in English. The presen- adults and children criticized the lack of dard uPVC pipe with solvent-cemented tation was very good, with plenty of lateral stiffness in the handle mechanism. joints. Pumprods are not sealed. The cylin- drawings in a clear, lively style. However, The overall conclusion of the der is a length of thicker walled uPVC pipe the instructions for installation did not laboratory tests was that the IDRC-UM is a and has an all-plastic plunger fitted with make clear how the pump should be pump designed for Malaysia and with polyethylene ring seals. The basic installed in relation to ground level. limited scope for wider application. It is components of the plunger are also used The all-plastic below-ground assem- suitable only for depths of 12 meters or in the footvalve, which can be extracted bly is easy to install, and the pump is des- less, where it has to compete with inhe- without withdrawing the rising main, by igned for both the plunger and footvalve to rently simpler direct-action pumps. The removing the piston and attaching an be removed for subsequent main- wooden handle links proved to be durable extractertotheendofthepumprod. tenance and repair, without extracting in normal use but susceptible to abuse. the rising main. Installing the above The plunger seals wore rapidly in sandy Manufacture ground parts requires skill to ensure that water. Plastic molding skills and facilities are the pumpstand is correctly assembled and It is understood that, with further field needed, along with simple uPVC and metal securely mounted at the well head. trial experience, the University of Malaya machining. Construction is simple. Prefabricated uPVC components will be is now supplying a Mark 3 version, which required if the rising main breaks at the is said to be more robust (the version Suppliers spout connection. tested was Mark 1). It has metal instead of Dept. of Mech. Engineering, University of The 4000 hour endurance test was wooden handle links; the plunger rings Malaya, Kuala Lumpur, Malaysia. carried out at approximately 30 cycles per have been redesigned to increase dura- minute, with a simulated head of 12 bility; and the pump is now bolted to a Indicative prices - Apr 1985 meters. In the first few hundred hours of concrete pedestal. This new version is the test, there were repeated failures of being installed by the Ministry of Health in Pump, per unit US$ 290 the upper pumprod due to excessive ang- Malaysia and is being field tested by IDRC Pumprods, per meter US$ 2.00 ular movement during the pumping cycle. in several countries in Africa and Asia. Rising main, per meter US$ 5.00 FOB Port Kelang, Malaysia 154 PUMP 29 IDRC-UM Field Trials Assessment -^5F In the absence of field trials, the IDRC-UM ratings are based onthe j' ) | > > * t pump's performance in laboratory tests and on the experience and judgment of Project staff. Discharge Rate A relatively high discharge rate can be achieved, earning the M = ; f, > !9g . 1 pump a "good" (oo) rating (though the work input is comparatively high at 12 meters lift). t_6 :s- , s ~~~Ease of Maintenance Maintenance is quite simple, but the degree of skill needed to assemble the pumpstand means that the oo rating for maintenance THE IDRC-UM PUMP WAS NOT FIELD TESTED BY THE systems B and C reduces to HANDPUMPS PROJECT "adequate' (o) for system A (village-level). Reliability The IDRC-UM is best suited for light use and earns a oo rating for a daily output of 1.5m3/d, red- ucing to o at 4m3/d. The pump is not recommended for higher daily output. Corrosion Resistance Use of all-plastic components eams the pump a oo rating. Abrasion Resistance The plunger, seals and cylinder showed considerable signs of wear after pumping sandy water, and the pump is not considered suitable where sand pumping is expected.. Manufacturing Needs The IDRC-UM has been designed for manufacture in a developing country (Malaysia) and earns a oo rating for countries with moderate or high levels of indus- trial development (Categories 2 and 3). The machining and steel fabrication needed reduces the rating to o for countries with only a low level of industrial develop- ment (Category 1). PUMP 29 155 The Netherlands M.,kil Laboratory Tests Date tested. 1980 Reported: O.D.A. Report 1981 Care is needed to ensure an adequate ______________________________ seal at the welihead. s < > Performance data The most frequent maintenance Petfical values) requirement is likely to be to replace the (typical values) spring in the pumpstand. This is a straight- Flpedsj Head (meters) 7 7 forward task, but requires a supply of suit- / - , H Pumpingrate able spare parts. Below-ground mainte- Pu cinclaes ii 2 nance requires the whole assembly to Volue m l(cyclesmin 20 48 extracted, but this is also relatively easy. ( >. Volume min (liters) 1 0 24 wasFor endurance testing, the pump Input (watts) Not recorded was driven at 40 cycles per minute at a Mechanical efficiency (%)15 12 head of 7 meters. The spring broke after Maximum footplate 250 hours and again after 400 hours, at force (kg-f) 90 110 which point the test was stopped. Corro- l Leakageoffoot sion was not assessed; however, all the valve fmrimin) Notrecorded below-ground parts are plastic, brass or stainless steel, and the spring in the pumpstand is also stainless steel. Figures are for 2-inch cylinder The pump proved to be resistant to impacts. General Description Some users found the pump difficult Evaluation to use, particularly where their body The Kangaroo is a direct action pump with The two test pumps were collected from weight was insufficient to compress the a unique form of action. Foot-operated, its the manufacturer's factory in the Nether- spring. upstroke is provided by the relaxation of a lands, and the normal method of packing The overall conclusion of the spring compressed by the operator on the was therefore not assessed. laboratory tests was that the Kangaroo is downstroke. Below-ground components No instructions for installation, unsuitable for community water supply. It are the same as those of the SWN 80 & 81 maintenance or repair were provided. is difficult to use, the range of working (Pump 20), consisting of a uPVC cylinder, Because the below-ground assembly was depth is very limited, and the spring inside neoprene double-acting cupseal, and plun- light in weight, installation was relat- the pumpstand proved to be very ger made from stainless steel and nylon. ively easy, with no need of lifting tackle. unreliable. Pumprods and connectors are stainless steel, with each connection encased in polyethylene hose, to combat abrasion of the uPVC rising main. Valves are brass with rubber sealing faces. Different cylin- der diameters are available to suit different depths. Two models are made: Mark 1, with square telescoping tubes around the spring; and the heavier duty Mark 2 with circular tubes. Manufacture The manufacturer supplies parts to be welded and assembled in developing countries. The spring would have to be purchased from a special manufacturer and below ground the components call for a high degree of skill and quality control. Sup,phers Van Reekum BV, Kanaal Noord 115, Post- bus 89, 7300 AB Apeldoorn, Netherlands. Indicative prices - May 1985 Pumpstand only US$ 896 Riser/rod in 3m lengths US$ 94 156 PUMP 30 Kangaroo Field Trials Assessment Test conditions ~ ~ ~ ~ ~ ~ Assssen Test conditions p, t The Kangaroo ratings are based Number Head Data I on limited field and laboratory Number Head availa trials, together giving reasonable Country pumps (metlablers) (mon) - [.U1J data from which to draw conc- Country pumps (meters) (months) ___ lusions about the pump's perfor- Tanzania 10 4-7 13 Dischargmance. l__ ___ ___ ___ ___ ___ ___ _ _ The Kangaroo is capable of relatively high discharges and earns a 'good" (oo) rating for both The field trial was conducted on the 7 and 12 meter lifts. Mtwara project in Tanzania, and the humid spring being hard to replace and the under- Ease of Maintenance atmosphere was a severe test for the ground components difficult to remove. The pump is not suitable for Kangaroo pump's steel spring. The down- Installation is complex, because the village-level maintenance, but is hole components of the pump are identical pump is heavy and connection of the within the capacity of an area to those of the SWN80 & 81 (Pump 20), rising main to the pumphead requires a mechanic to maintain, and so and again proved highly resistant to minimum of two skilled people. rates oo for maintenance abrasion and corrosion. User reactions were generally systems B and C. The pumphead however did not favorable when the pumps were working. Reliability perform well. Though the trial was limited People liked the foot operation, and the The frequency of necessary - only ten pumps for a little over a year capacity to employ full body weight in a repairs combined with the need and shallow lifts - the measured failure comfortable way. for area-mechanic maintenance, rate was 1.5 breakdowns for every In general, the conclusion of the means that the pump is not 100Om3 of water pumped. All the failures field trials was that the Kangaroo's reliable for high daily outputs. It is were associated with the pumphead, and innovative design is let down by major rated "adequate" (o) for 4m3/d and involved broken springs and some broken problems with the pumphead. The system oo at 1 .5m3/d. footplates. Even working springs exhib- is judged too complex, when compared Corrosion Resistance ited severe corrosion. Though the pump with a conventional direct action pump Downhole components of the can be operated by hand when the spring using a high displacement pumprod, with Kangaroo are highly corrosion is broken, it is a heavy lift, requiring two which the operator can achieve the resistant, but the susceptibility of strong men. upstroke without the need for a spring. the spring to suffer in the The pump is difficult to repair, the corrosive conditions of the field trials reduces the rating to o. Abrasion Resistance The downhole components of the Kangaroo proved highly resistant to abrasion, confirming the results obtained by the SWN 80 & 81, which use the same compo- nents, and eaming a oo rating. Manufacturing Needs The complexity of the pumphead CAUSES OF ESSENTIAL INTERVENIIONS assembly makes the Kangaroo CAUSES OF ESSENliAL INTERVENTIONS unsuitable for manufacture in 2- 2 -0 developing countries with a low 1.8- level of industrial development ^ 1.6- va (Category 1). The degree of o -us < quality control needed means a o o t<4- i ;-0.5, rating for Category 2 (moderately S 1.2- * ts o developed industrial base), and '- 1- - -1 the pumps scores oo only for 5 _ .S L manufacture in a Category 3 t., 0.8- * . __1 tL environment (highly developed 0.oo4- l | -0.5 t industry). 0.2- 0 0 -1.5 TOTAL HO F RH PR RM PS PE FV OT PART REPLACED HO-Handle RH-Rod hanger RM-Ri,s,ng ma,n PE-Pumping ele-ent F-Fulcrum PR-Pump rod PS-Piston seal FV-Foot valve OT-Othe, PUMP 30 157 Malawi Laboratory Tests THE MALAWI MARK V PUMP HAS NOT BEEN TESTED IN THE CATR LABORATORY I General Description The Mark V is a shallow-well direct action pump developed in Malawi and designed for local manufacture and to suit local need for a corrosion resistant low-lift pump. The pump continues to undergo design modifications, and this description relates on;y to the pumps tested in the field trials. The pumpstand is made from galvanized steel pipe and standard galvanized pipe fittings, and fits into a screwed socket cast into the well cap. The 32mm diameter PVC pumprod passes through a polypropylene bush and is connected to a hardwood T-handle via a length of galvanized steel pipe. The uPVC plunger has a low density polyethylene sleeve fitting into a 56mm diameter PVC rising main which also forms the cylinder. A high density polyethylene disk forms the plunger check valve, while the footvalve has a rubber disk in a uPVC body. Manufacture The pump was specifically developed for manufacture in Malawi and could be made in any developing country where the variety of plastics materials are available in good quality. Suppliers The Secretary for Works and Supplies, Department of Lands, Valuation and Water, Private Bag 390, Capital City, Lilongwe, Malawi. Indicative prices - Jun 1985 Complete pump, including rods and rising main US$ 135 158 PUMP 31 Malawi Mark V Field Trials Assessment Test conditions __ Assmn Test______conditions ___________ The Malawi Mark V ratings are Number Head Data ;.~ w '* \'~ * >based on monitoring of a large of range available sample of pumps over a reason- Conty pup (meters (months)e able period of time, giving a good Country pumps (meters) (months) Pr ; ^ g f wdegree of confidence in the judg. Malawi 61 2-10 22 ments made. As a direct act,on pump, it would be limited to lifts of ______________________ _ -less than 12-15 meters, and the field experience has shown that The Malawi Mark V was an early example the present design is not suitable of what has become an important pump strengthened, the Mark V fails at another for use beyond 7 meters lift. group for low lifts - the direct action high stress point, where the pumprod joins Discharge Rate pumps. It makes extensive use of the plunger. The pump is capable of achieving pumps. ~~~~~~~~~~~~~~~~~~~~a high discharge rate and earns a plastics, and has been designed for quick The top guide bush wore rapidly, and 'good" (oo) raling under this and simple maintenance. However, there there was some scoring of the plastic heading are some serious design flaws, which rising main when pumping sandy water, Ease of Maintenance have resulted in rapid breakdown in the though the seal-less design is generally The simplicity of parts replace- field trials. abrasion resistant. ment on the Mark V should make The types of failure which have Because of the frequent stress it well suited to village-level main- occurred have demanded more than failures in the field trials, the Mark V tenance. However, the common straightforward replacement of parts, cannot be recommended for lifts beyond 7 breakages of rodhandle and involving skilled repair, with the need for meters, and even then is only appropriate rod,plunger connections require solvent cement, etching fluid and tools forcomparativelylightuse. skilled repair, which reduces the which would not be available to a village Under those conditions, it does have rating to 'adequate' (o) for main- caretaker. the merit of complete corrosion resis- tenance system A. Failure of the connection between tance. It is also capable of delivering a Reliability the T-bar handle and the PVC pumprod high amount of water per stroke, which The frequency of essential was the commonest form of such break- makes it popular with users when it is repairs combined with the need downs. This is a predictable weak point, working. for skilled assistance in carrying but even when the connection has been them out restrict the Mark V's recommended application to low duties it is raled o for a daily output of 1 .5m3/d at 7 meters lift. Corrosion Resistance Use of all plastic parts below ground earns a oo rating. Abrasion Resistance The seal-less design cuts down abrasion, but scoring of the PVC cylinder wall limits the rating to o. Manufacturing Needs CAUSES OF ESSENTIAL INTERVENTIONS Manufacture of the Malawi Mark V is simple and could be readily 1- 0.7 -14 accomplished in most developing 0.9- countries. The demonstrated 0.8- 0.6 12 need for high qualiiy plastics o 0.7 ^ 10 restricts the rating to o in a 0.7- i -0.5 t -1v > countries with only low levels of 0.6 --. 00.4 8 industrial development (Category 00.5- a 1). r 0.4- 0-0.3 6 6 0.3- 0.2 4 0.1 2 0 0.1 O 0.0 0 TOTAL HD F RH PR RM PS PE F1 OT PART REPLACED HD-Handle RH-Rod hanger RM-Rising m.ain PE-Pumping element F-Fulcrum PR-Pomp rod PS-Piston seal FV-Foot valve OT-Other PUMP 31 159 Finland Laboratory Tests Date tested: 1986 Reported: Not yet reported Performance data (typical values) - 58mm dia cylinder Head (meters) 7 1 0 Pumping rate (cycles/min) 30 30 Volume/min (liters) 26 24 Input (watts) 70 85 Mechanical efficiency (%) 42 45 Maximum handle force (kg-f) 18 down 24 29 up 31 Footvalve leakage (ml/min) No significant leakage Evaluation rubber valves were replaced with polyur- The two test pumps were securely packed ethane moldings, for both this pump and in wooden cases, and were in good the Nira AF84 deepwell pump (Pumpl 8). condition on arrival. The manufacturer At the end of the test, the plunger and subsequently supplied new valve poppets cylinder were badly worn, and the rate of to replace those in the original consign- delivery from the pump was considerably General Description ment. reduced. The rising main and pumprod Instructions for installation and were also locally worn as a result of The Nira AF85 is a direct action pump maintenance were supplied with the test contact between them. The latest valves developed as a result of, and with samples. They consisted mainly of draw- showed few signs of wear, but were feedback from, the Project field trials. The ings and photographs, augmented by a beginning to crack. The manufacturer has pumpstand is made from fabricated steel small amount of text, in English. The inst- since made further modifications to the and is nylon coated for corrosion allation instructions were comprehensive valves. There was no corrosion. protection. A stainless steel T-bar handle and helpful, and a full set of tools was also The pump proved to be robust in the slides in a long guide bush made from high provided. Installation was easy, with impact tests; although heavy impacts on density polyethylene (HDPE). A footplate no need of lifting tackle. the pumpstand bent it a few degrees out of isboltedtothebottomofthepumpstand. In contrast with the installation litera- vertical, the pump could still be used The rising main and large diameter ture, the instructions for maintenance without difficulty. The pump completed pumprod are made from polyethylene and were very brief. Nevertheless, the light the allotted 96,000 cycles of the handle both originally had brass screwed coup- weight of the below-ground assembly, and shock test without failure. lings, but the pumprods are now conn- the simplicity of its design, mean that only In the user test, the smaller children ected using polyethylene couplings. Tight a few tools and a modest degree of skill found it difficult to achieve the necessary fitting rubber plugs prevent water ingress will be required to maintain the pump in operating force on the upstroke, but at the ends of pumprods. Plunger and working order. On the pumpstand, the adults commented favorably on the rate of footvalves are in HDPE with identical only item likely to require attention is the delivery from the pump. Several users molded rubber bobbins. The plunger seal is pumprod guide bush, and this is easy to found the footrests uncomfortable to use, also HDPE. Valves are interchangeable replace using a single hexagon key. and would have preferred to stand on the with those on the Nira AF84 (Pump 18). For the 4000 hour endurance test, ground beside the pump. Manufacture the pump was driven at approximately 30 The overall conclusion of the Use of expensive imported materials is a cycles per minute, at a simulated head of laboratory tests was that the Nira AF85 is constraint to manufacture in developing 10 meters. A device simulating the inhe- a generally robust pump of simple design, countries. rent buoyancy of the sealed tubular pump- well-suited to the requirements of VLOM. Suppliers rods was also fitted, and the driving There was considerable wear of the Vammalan Konepaja Inc, 38200 Vammala, mechanism was so arranged to impose a plunger seal, particularly in sandy water, Finland. lateral force on the pump handle similar to but the pump is easy to maintain and that typically applied by users. repair. The new valve design introduced Indicative prices - Feb 1985 For the first phase of the test, with by the manufacturer in consultation with clean water, the pump was fitted with the laboratory represents a significant Pumpstand, cylinder, rods, molded rubber valves. The footvalve improvement. The pump also has consid- and rising main to 10.5m US$ 340 failed shortly before the end of this phase, erable potential for manufacture in when the rubber extruded into the valve developing countries, though specialist port, causing the valve to seize shut. In equipment for molding the polyurethane consultation with the manufacturer, the valves is unlikely to be widely available. 160 PUMP 32 Nira AF85 Field Trials Assessment Test conditions Asse-ssmen ____________________ -- l ;The Nira AF85 ratings are based Number Head Data - on data from comparatively short _ _ _ _ __of range available . field trials involving only small Country pumps (meters) (months) Jr_ numbers of pumps. However, with the laboratory test data and Tanzania 13 0-9 12 - observations of additional pumps Kenya 7 2-15 9 -0 in other locations, there is adequate information for judg- Malawi 10 1-10 6 ments to be made. As a direct action pump, the Nira AF85 has a Though only a few Nira AF85 pumps have W a practical operating limit of 12-15 been monitored in the field trials, and data Lmeters is therefore limited, increasing numbers of Discharge Rate pumps have been installed during the A high discharge rate can be latter stages of the Project, allowing achieved comfortably, and the judgments to be made beyond those PUMP ears a goodf ool rating. reflected in the record of interventions _ - _ _. ThEase of Maintenance represented below.___The Nira AF155 is well Suited to Ovreerall,ntedhbelow. pumphasperformed susceptibletoabrasiondamage,butthe village-level maintenance and Overall, the i pu hserformed susceptible to abrasion damage, but the earns a oo rating under each very well. It is popular with users, being sealing provided by this ring is not possible mainlenance system very easy to operate down to heads of important, because of the high plunger Reliability about 12 meters, and giving a high dis- velocity, which means that the pump will Because of the quick and simple charge. One significant problem has been continue to lift water if the seal is damaged maintenance, the pump is rated failure of valve bobbins. This has been (even without the seal). oo for reliability for all uses brought to the attention of the manufac- The manufacturer has made several excepi a daily output of 8m;'d at turer as a result of which the valve has substantial modifications to the pump 12 meters lift, which represents recently been substantially redesigned design during the field trials, partly in very heavy use for a pump of this and further problems are not expected. response to suggestions made by Project nature. The rating then drops to The Nira AF85 is very easy to install staff. The changes have proved generally 'adequale (o). and to maintain, requiring only two simple successful. They include standardizing on Corrosion Resistance bolt spanners to disconnect the rising one cylinder size and simplifying the All downhole components are main. Removal and replacement of the connection of the top bush to the corrosion resistant, earning a oo entire pump can be achieved by two pumphead. rating. people in about half an hour. Overall, the judgment is that the Nira Abrasion Resistance The use of plastics, stainless steel AF85 is an important pump for lifts of up to Heavy sand pumping will lead to and brass for downhole components 12 meters, using the most up-to-date wear of the plastic piston ring, but gives good corrosion resistance. The thinking and producing good results, this has a limited effect on pump pump uses a plastic piston ring, which is though the price is high. performance. justifying the o raring tor abrasion resisTance Manufacturing Needs The Nira AF85 is relatively simple CAUSES OF ESSENTIAL INTERVENTIONS to manufacture, but the need to 2 _ _ _ _ _16 import some matenals reduces 2.- 3 1 the raiing to o for countries with 1.8- TANZANIA 2.5 14 only a low level of industrial deve- j¶ 1.2- -2.5 12 lopment (Category 1). The rating g1.4-N is oo for Categories 2 and 3. o ~~~~~~~~~~~~1.55 -8 I- wI 0.6- 0.6- 1 -6. ' i. 0.4- E m4 0.2- _ __ _ -2 O- 0 . , ,0w O - TOTAL HD F RH PR RM PS PE FV OT PART REPLACED HD-Handle RH-Rod hanger RM-Ris.ng main PE-Pumping element F-Fuicrum PR-Pump rod PS-Piston seal FV-Foot valve OT-Other PUMP 32 161 Bangladesh Li E }Laboratory Tests =;] Date tested: 1985 Reported:Applied Technology Note No.2 carried out at 30 cycles per minute, with a /_______________________________ simulated head of 15 meters. Special arrangements were made to simulate the Performance data buoyancy effect of the pumprod, and the (typical values) mechanical drive was set up to match the _____________________________ out-of-line forces typically applied by Head (meters) 7 15 users operating direct action pumps. Pumping rate ~~~~~~There were no failures in the first 2000 Pumping rate ~~~~hours of testing, using clear water. How- (cycles/min) 21 20 ever, the Tara did break down repeatedly - ~~~~~~~~~~Volume/mmn (liters) 24 23 during the initial stages of the final 2000 Input (watts) 53 97 hours of testing, when sand and Mechanical Kieselguhr had been added to the water. efficiency (%) 51 58 Fragments of uPVC jammed under the Maximum handle leather cup seal caused the pump to force (kg-f) 18 down3l seize, and the problem was repeated 20 up . 35 several times when new leather seals were Footvalve leakage fitted. It was thought that sand particles (mlmin) Not significant embedded in the leather seal abraded the U , '4f cylinder walls. Substitution of a nitrile The volume discharged per stroke rubber cup seal overcame the problem. was about 1.2 liters and was not At the end of the 4000 hours, the foot General Description affected bypumping rate. valve was leaking badly and the pattern of Performance was tested for a the valve ports was impressed in the The Tara is a direct action handpump cylinder immetsion of 5 meters. piston valve rubber, but the valve was still ThdeTara isvaldirect action hangandeus (Seenderimmersionof5mete. In good working order. The nut on the under development in Bangladesh (See piston spindle had rusted on tightly and Box 4.7 in Chapter 4). The pumpstandpitnsndehdrtdonbtlad casing is fabricated from steel. Pumprod Evaluation the footvalve body had jammed in the and rising main are standard uPVC piper The two test pumps were well packed and taper seat, making it impossible to remove The cylinder is also uPVC pipe of the same were received in good condition. Cylinder from above. Except for the piston spindle outside diameter as the rising main but pipes were supplied, but uPVC pipe for the nut, corrosion was limited to surface greater wall thickness. When used in the rising main and pumprod was bought marks on the aluminum components of the small diameter tubewells constructed in locally, piston. Bangladesh, the rising main also serves Installation and maintenance instruc- The pumpstand withstood the impact as the well casing. tions were included in a comprehensive tests, suffering slight bending of the base- The piston is machined from aluminum album of drawings and specifications, plate, but remaining serviceable. The and has a simple rubber flap valve. A which might be considered overwhelming handle was subjected to a shock test invol- similar rubber flap is used on the molded at the village level. Specific installation ving repeated banging against the lower plastic footvalve. Fittings on the piston instructions were supplied later, and stop. It survived the allotted 96,000 and footvalve enable them to be coupled included clear line drawings and guidance cycles without failure. together and removed for maintenance or on site selection. The Tara's proportions and the dist- repair without extracting the rising main. Only simple hand tools are required ribution of effort between upstroke and Manufacture for installation of the Tara, and all the downstroke make the pump well-suited for The Tara has been designed for manufac- components are light and easy to handle. direct action by most users, though at 15 ture in Bangladesh, and involves simple Care is needed to ensure that all the pump- meters depth and with a cylinder immer- steel fabrication, some thermal forming of rod joints are watertight, as the buoyancy sion of 5 m, the required forces are diffi- uPVC pipe, machining of aluminum, and of the rod is critical to pump performance. cultforchildren. simple plastic molding. The design It is also important that the joints on the The overall conclusion ol the provides scope for use of alternative rising main should point downwards, to laboratory trials was that the Tara is a materials where appropriate. enable the piston to be extracted for main- VLOM pump, designed to exploit the tenance. materials and manufacturing skills indi- Suppliers The grapple device below the plunger genous to Bangladesh, with potential for Mirpur Agricultural Workshop and Training makes it possible to remove the footvalve further improvement and wider application. School, Pallabi, Dhaka-16, Bangladesh. for maintenance without extracting the Relatively easy to manufacture, operate, rising main, though some care is needed maintain and repair, it is seen as suitable Indicative prices - Mar 1985 to avoid damage to the pumprod as it is for community water supply use for lifts of lifted out. All maintenance operations 15 meters or less, and should be fitted with Per unit, including rods and can be performed by a village caretaker. a nitrile rubber seal if sand may be rising main to 11 meters US$103 The 4000 hour endurance test was pumped. 162 PUMP 33 Tara Field Trials Test conditions Assessment The Tara ratings are based on the Number Head Data i pump's performance in both field pump (mnetaalbers (months is trials and labGratory tests. For a pumps (meters) (months) 311 1 5direct action pump, the practical Sri Lanka 20 3-11 15 ,. -- operating limit is 15 meters, and Bangladesh 128 3-12 11 _ .4 , the pump is therefore included Kenya 10 12 7 1 only in Tables S.1 and S.2. Tanzania 5 2-6 6 - Discharge Rate Malawi 6 1-3 11 A discharge rate of more than 20 Bolivia 16 4-11 14 liters per minute earns the Tara a China 44 7-14 4 =-_ U;|W , "~~~~~~~~~~~~good" (Oo)rating. This report concentrates on the results of Ease of Maintenance testing in Bangladesh, where design modi - -_ The Tara is a true VLOM pump fications have been made as testing - and earns a oo rating for main- progressed. _ tenance under each possible The most important aspect of instal- maintenance system. lation is proper jointing of the PVC pipe for - Reliability pumprod and rising main, and some mas- essential interventions were mainly to rep- Under conditions of low usage onry skill is needed to embed the pump- lace footvalve parts (0-rings and body) or and 7m head, ihe ease with which stand lower flange in concrete. An leather cupseals. Sand entry into the well maintenance can be carried out average pump installation was completed is a problem in Bangladesh, and leather gives the pump a oo rating for in six hours by four workers. cupseals are not suitable in these con- reliability, but for higher daily out- An average of three essential inter- ditions; nitrile rubber seals have proved puts, the frequency of essential ventions was needed for each pump in substantially better. interventions to replace cup approximately two years of testing, mostly The field trials also revealed potential seals or footvalve components to correct poor performance. Including problems caused by abrasion of the seal reduces the rating to 'adequate" preventive maintenance and other non- on the PVC cylinder and between the pump- essential interventions, each pump rod and rising main. Nitrile rubber guides (0) at 4m3/d and to 'unsuitable" received some kind of maintenance atten- are being investigated (see also Box 4.7 in (-) at 8ml-d. At 12m lift, the tion about five times in the year, with the Chapter 4). There were no complaints from pump achieves a o rating for a average intervention lasting about two users about the mode of operation of the daily output of 1.5m3, but is hours, and involving a labor cost of Tara, and the high discharge was liked. unsuitable at this stage of its US$0.37 and a spare parts cost of The Taras also continued to work when developmentforhigheroutputs. US$0.39. Since June 1985, groups of suction pumps failed in the dry season, as Corrosion Resistance three women caretakers have been ser- the water table dropped. Most of the pump's components vicing ten pumps per group, with encou- The Tara trials showed that the pump are corrosion resistant, but expe- raging results. has great potential, though some problems riences in the laboratory and the Among the 128 pumps under test, remain to be solved. The number of inter- field with the footvalve assembly there was a total of four breakdowns, two ventions needed was high, but the speed mean that the appropriate rating due to pumprod breakage, and two due to and simplicity of repairs meant that few is 0. uncoupling of the bottom connector. Other pumps were out of action at a time. Abrasion Resistance CAUSES OF ESSENTIAL INTERVENTIONS Sand caused severe problems 11- 4 -0.30 ~~~~~~~~~~~~~with the leather cupseals, and 1-_ -E0.30 nitrile rubber seals are therefore 10- | -3.5 8 $ essential if there is a possibility 9- BANGLADESH E SRI LANKA 3 0.25 M of sand entering the well. ,,NGLADEH 8- SRI LANK 3 Manufacturing Needs & $ 0.20- The Tara has been specifically 6 - .fidesigned for manufacture in Bang- 5 S- 5 -~~~~~~~~~~~~2 -O.IS ladesh, and is suitable for modi- 5 L | - 1.5 fication (using alternative mate- -0.10 rials) to take advantage of indi- 2 3- t | | o1 5 ffl genous materials and skills in any 2- -0.5 r o.osC developing country. The need for ,- 1 n ^, | -0 5 E tt some assistance with quality 0 iLo~~~~~~~~~~ L0.00 control reduces the rating to o for TOTAL HD F RH PR RM PS PE FV OT manufacturing environment 1. PART REPLACED HD-H.ndle RH-Rod hanger RM-Ris.ng ma.n PE-Pump,ng element F-Fulcrum PR-Pump rod PS-Piston seal FV-Foot valve OT-Olher __. PUMP 33 163 Sri Lanka Laboratory Tests NEITHER THIS SHALLOW-WELL VERSION NOR THE SRI LANKAN MANUFACTURED DEEPWELL AID DERIVATIVE WERE TESTED IN THE CATR LABORATORY. HOWEVER, THE LABORATORY REPORT ON TWO AID DEEPWELL DERIVATIVES WHICH WERE TESTED CONTAINS SOME RELEVANT DATA SEE ENTRY FOR PUMP 03 General description This is a shallow-well version of a pump derived from the basic design developed by the Battelle Institute and Georgia Inst- itute of Technology on behalf of USAID. The pumpstand is similar to the deepwell version (Pump 03) and consists of a cast iron drive head assembly and cast iron base joined by a steel tube. The base is flanged to bolt to the plafform. In this suction version, the steel tube is lined with 75mm ID PVC pipe and a 32mm ID PVC suction pipe extends down to the desired pumping level. Two out- board cast iron cleats on the rodhanger axle slide up and down in cast iron run- ners. The fulcrum stand is pinned to the pumpstand below and the handle above, so that the fulcrum moves in an arc as the handle is operated. A cross head guides the pumprod. Manufacture Basic skills in foundry work, machining and leather crafting are needed to manufacture the pump and careful quality control is needed to ensure interchan- geability of spare parts. Suppliers Diason Pumps Ltd, 112 Isipathana Mawatha, Colombo 5, Sri Lanka. Indicative prices - 1982 Per unit, excluding suction pipes US$ 120-160 164 PUMP 34 AID Suction Field Trials Assessment Test conditions - The ratings are based on field Number Head Data ? w | - T trials in Sri Lanka. As a suction of range available pump, this AID Derivalive is Country pumps (meters) (oths) appropriate only for pumping lifts I , of 7 meters or less. It also requ- Sri Lanka 1 3 2.8^-4.8 1 1 'Dires priming and is therefore at risk of contamination if polluted -- _ e water is used for the purpose. Averagehead i Discharge Rate There were no major failures among the 13 The discharge rate of 24 liters per test pumps during the monitoring period. =- minute at 30 strokes per minute Three leather cupseals and one flap valve WW , eams a "good" (oo) rating. were the only parts replaced in essential Ease of Maintenance interventions. The PVC cylinders showed No special tools or lifting tackle little wear and the cross heads and suggesting that corrosion products may are needed, but for village-level guides, though worn, were still functioning have affected palatability. maintenance it will be necessary satisfactorily after 11 months. On the Impact can lead to water leaks at the to ensure that a village caretaker other hand, routine maintenance demands threaded joint between the cylinder and has access to spare cupseals were comparatively high. The drive head is the base flange; otherwise the pumpstand and valves. Assistance from an exposed and needs frequent lubrication is adequately robust. The pump's open area mechanic may be needed for (at least once a month) of fulcrum, eye design means that water can be contami- special repairs, and The rating and pivot pins. nated through the connecting rod hole, reduces from oo to o for System All moving parts are accessible and the spout profile is such that deli- A maintenance. above ground and maintenance tasks can berate contamination is possible. Split Reliability be easily accomplished by a trained mech- pins are easily removed and there are no The reliability rating is also oo for anic equipped with only pliers, a screw- locking fixings, so the pump can fall victim outputs of 1.5 and 4m3/d, but driver and three spanners. A new gasket to vandalism or abuse drops to o for 8m3/d, when the must be installed when the base flange is Users liked the relatively high dis- frequency of maintenance requ- detached to service the footvalve. charge rate of the pump (about 24 ired would be greater. It should No installation instructions were liters/minute at a comfortable 30 strokes a also be noted that the pump calls supplied with the pumps, but installation minute). Though there were potential finger for regular lubrication, and the was easily accomplished by one skilled traps around the fulcrum mechanism and ratings should be downgraded if worker and one helper using basic hand the sliding guide blocks, no injuries were such routine maintenance may tools. Pumps can be installed on a ground- reported. not be readily achieved. level wellhead without a plinth. As the bar chart shows, the parts Corrosion Resistance Because the moving parts of the replaced for every 1000m3 of water pum- A galvanized steel suction pipe drive-head assembly are not protected ped were very low (0.3). Though the test and exposed drive head compo- from dust, heat and rain, corrosion and period is short, it does seem that this nents make the AID Suction abrasion of these components is a pump will perform well for low lifts, unsuitable (-) where ground- danger. Complaints about the taste of the provided that the drive head is lubricated water maybecorrosive. water were noted at 10 of the 13 test sites, regularly. Abrasion Resistance Use of leather cupseals means a CAUSES OF ESSENTIAL INTERVENTIONS orating for abrasion resistance. 1~~~ 12 ~~Manufacturing Needs 1- -1.50 -12 The pump is suitable for manu- 0.9- facture in countries with a mode- 0.8- 1.25 10 rate level industrial base, but the ,, ¢ need for careful quality control of ° 0.7- -1 g -a O casting and machining operations i, 0.6 - § reduces the rating from oo to-in 8 0.5- -0.75 j 6 a a country with minimum manufac- 0.4o 3- -0.50 C ! turing capabilities (Category 1). 0.3- 0.50 -4 . 0.2- -0.25 -2 0.1- 0O- 0 -0 TOTAL HD F RH PR RM PS PE FV 0T PART REPLACED HD-Handle RH-Rod hanger RM-R,s.ng main PE-Pumping element F-Fulcrum PR-Pump rod PS-P,ston seal FV-Foot valve OT-Othe, a PUMP 34 165 Indonesia Laboratory Tests Date tested: 1983 Installation and maintenance Reported: Project Report No.3 is quite straightforward and requires only Note: The sample tested differed slightly simple tools, though no installation or Piston from the latest drawings supplied by the maintenance instructions were supplied manufacturer. The cast iron handle has with the pumps. Frequent attention is r replaced with one of galvanized iron; likely to be needed, particularly to replace th~e webs of the top fulcrum casting have cup washers. Three replacement cup been extended to increase strength; and washers were needed during the 4000 the connecting rod fork has been rede- hour endurance test which took place signed to remove the potential finger trap. at 30 strokes per minute at 7 meters head. At the end of the endurance test, rust was found on the sliding plate at the Suction Performance data pump top, in the plunger valve cage and check valve (typical values) inside the pump body above the cylinder (typIcal vauIs) _lining, though the cylinder bore remained Head (meters) 7 in good condition. Fulcrum pins and Pumping rate (cycles/min) 30 bushes were worn, and the plunger valve Volume/minute (liters) 29 was noticeably worn, but still serviceable. Input (watts) 47 The top fulcrum casting and the base Efficiency (%) 70 casting both broke during the Impact Maximum handle force (kgtl 16 tests, indicating a susceptibility to acci- dental damage, and the absence of lock Footvalve leakage (ml.'mnl 0.25 washers on the fixings lowers the pump's The volume discharged was about resistance to possible abuse. The labora- 1.0 liters per stroke and varied little tory noted a potential finger trap between with pumping rate. the connecting rod fork and the top of the I pumpstand, but later designs have elimi- General Description nated this danger. Evaluation User reactions were neutral: overall The Bandung is a suction pump with a The two pumps acquired for testing both few users criticized the pump and few conventional lever action. It is construc- arrived damaged, because of inadequate singled it out for praise. The handle move- ted mainly of cast iron, with an enamelled packaging. According to the supplier, the ment means that many muscle groups steel liner in the cylinder bore. The plunger pumps left the factory packed together in contribute to the operating action. is cast iron with a molded rubber cupseal a wooden crate and must have been sepa- The overall conclusion of the and the check valve is a rubber disk rated by the carrier. They arrived wrapped laboratory trials was that the Bandung is retained by a plastic cage. There are no in pieces of corrugated cardboard and inexpensive, but could be comparatively handle bearings; the mild steel pivot pins plastic sacks, with the handles of both easily damaged and is likely to need fre- bear on holes drilled and reamed in the iron pumps and a third spare handle broken quent maintenance. As with any suction castings. and one cylinder top casting cracked. pump, the Bandung has to be primed and Damaged components were replaced by is therefore susceptible to contamination Manufacture the manufacturer. if polluted water is used. The pump can be manufactured in a country with cast iron foundry and simple machining skills together with rubber/ plastic molding facilities. Quality control is necessary to ensure that the pivot holes in the handle fulcrum and fork are correctly aligned. Suppliers lwaco BV, West Java Rural Water Supply Project, Jalan Banda 25, Bandung, Indonesia. The pump is manufactured by several firms in Indonesia. Indicative prices - Mar 1985 Per unit US$65 166 PUMP 35 Field Trials Assessment In the absence of field trials, the Bandung's ratings are based on J[ L eii'X 54t ~~~~~~its performance in the laboratory, -1X5 { and on the best judgement of Project staff as to its likely perfor- mance in field conditions. As a suction pump, the Bandung is not suitable for lifts in excess of 7 meters. It also requires priming and is therefore at risk of contamination if polluted water is 4. - z \ aused for the purpose. r.AK * _ ll Discharge Rate The measured discharge rate of 29 liters/minute earns the pump a good" (00) rating. Ease of Maintenance Maintenance is simple and requ- ires few tools, earning the pump a oo rating for each possible main- ,3 __________ __ _ . tenance system. Reliability The reliability rating is oo for daily outputs up to 4m3, falling to "ade- quate" (0), at 8m31d, as the endu- rance testing suggests that more THE BANDUNG PUMP WAS NOT FIELD TESTED BY THE frequent repair interventions will HANDPUMPS PROJECT then be needed. Corrosion Resistance Some corrosion was noted in the laboratory trials, which indicates that the pump cannot be recomm- ended for use where groundwater is likely to be highly aggressive. However, rusting was mainly confined to the pumphead, so the pump is given a o rating. Abrasion Resistance The rubber seals failed compara- tively frequently during the endu- rance tests, so the pump earns only a 0 rating for abrasion resistance. Manufacturing Needs The Bandung is suitable for manufacture in countries with a medium-level industrial base, but the degree of quality control needed makes it unsuitable for manufacture in a country with a low-level base (Category 1). PUMP 35 167 India Laboratory Tests / THE INALSA SUCTION PUMP WAS NOT TESTED IN THE CATR LABORATORY General Description The Inalsa Suction is a shallow-well suction pump with a cast iron pumpstand and fabricated mild steel top plate assem- bly. The cylinder is machined in the cast iron stand. Sealed ball bearings are fitted in the linkage pivots and the pumprod passes through a brass bush in the top plate, which also has a plugged hole for priming. The risk of contamination is there- fore less than for other suction pumps. Pumprod, handle and links are galva- nized steel. The plunger and valves are cast gunmetal, with a leather plunger seal and rubber valve seals. Manufacture The Inalsa Suction pump can be manufac- tured in a country with adequate skills in foundry work, simple sheet metal work, basic machining and simple leather work, but exacting quality control is needed, in particular to ensure a smooth surface on the cast iron cylinder. Suppliers Industrial and Allied Sales Private Ltd (INALSA), Suriya Kiram, 19 Kasturba Gandi Marg, New Delhi 110001, India. Indicative prices - 1983 Price per unit US$127 excluding suction pipe and footvalve 168 PUMP 36 Inalsa Suction Field Trials Test conditions Assessment _ _r The Inalsa Suction ratings are Number Head Data based on the pump's performance of range available -2- N = in field trials in India. As a suction Country pumps (meters) (months) _ pump, it is not suitable for pum- ~, j e : ping lifts in excess of 7 meters, It India 5 1 .9*-3.7 13.2 ; also requires priming, and is there- _________5__ -3_______:__._______ I . fore at risk of contamination if *Averagehead polluted water is used for the "Average head r # ~ jg . - ~ > . ,< purpose. The field trial pumps had only low useage Discharge Rate - average output for the five pumps was conditions (less than 5 meters head). The discharge rate of 25 liters per just 0.7 m3/d. There were no complaints from minute eams the pump a "good" No literature was supplied with the users about operation of the pumps, but (00) rating underthis heading. pumps, but only basic tools and skills are the irregular discharge pattern from the Ease of Maintenance required for installation. Average instal- spout caused by built-in baffles was regar- All wearing components are easily lation time was half an hour and involved ded as a nuisance. Complaints about the serviceable with hand tools, but three workers. The pump base should be taste of the water were noted at four of the there are problems in aligning the at least 300mm above the welihead for five test sites, supporting Project staff's top plate. The pump therefore comfortable pumping. belief that combining brass fittings with scores oo for maintenance Sys- No breakdowns occurred in the 18 ferrous metals can lead to galvanic corro- tem B (area mechanic), but only month test period, but a total of 14 leather sion in aggressive waters. Slight rusting "adequate" (o) for System A cupseals were changed in that time, and it was detected on the inner portions of the (village-level). seems that the cupseals will last from 4 to pump body. Reliability 6 months, depending on the intensity of The test pumps had low-grade Because maintenance is compara- use and the cylinder roughness. Frequent leather cupseals, which accounted for the tively quick and easy, the reliab- maintenance was also needed to adjust majority of maintenance interventions, ility rating is also 00 where usage the alignment of the fulcrum plate and and which could be expected to wear even Is low, but when the daily output piston rod, to avoid accelerated wear on more quickly if sand was present in the rises, the anticipated frequency of the guide bushing and the cup seal. Most water. Abrasion would also be a risk in seal replacement means that maintenance tasks were found to be those circumstances. downtime will be greater, and the simple to perform, requiring only two open The pumpstand was found to be rating drops to (0) at 4m3/d and spanners and a 450mm pipe wrench. Care generally robust, and the baffles offer "unsuitable"(-) at8m3/d. was needed to avoid overtightening of the resistance to abuse, by preventing debris Corrosion Resistance check valve cage, which could lock open from entering the pump. Some finger traps The present design incorporates the poppet valve. The lever arrangement are apparent around the handle fulcrum. brass and ferrous metal parts, did not require lubrication over the test Overall, the Inalsa Suction pump which have been shown to lead to period. On average, each maintenance compares favorably with the other two suc- galvanic corrosion, and the pump intervention lasted for one hour, at a cost tion pumps used in the India field trials. cannot therefore be recommended of $0.50. The two major maintenance needs could for situations where water is At 30 strokes per minute, the pumps be reduced by design improvements and corrosive. delivered 25 liters/min under the test useofbetterqualityleathercupseals. Abrasion Resistance The leather cup seals failed CAUSES OF ESSENTIAL INTERVENTIONS ~~~~frequently in the field trials, even CAUSES OF ESSENTIAL INTERVENTIONS with low usage, and would be more 10t -2.9 -120 susceptible to failure in sand- 9- " laden water, which is why the t- *2 -100 pump is rated - for abrasion aO 7 . fl t resistance. _ -80 0 Manufacturing Needs § 6- - - 1.5 E The Inalsa Suction is suitable for 5- 60 manufacture in countries with a S ¶ - 1 (s medium-level industrial base, but e 4 - - = -Xo es the degree of quality control 2 0.3 - - Cneeded reduces the rating from f 2 ** 0.5 IL -20 t 00 to-in a country with minimum I manufacturing capabilities (Cate- a] 0 .L . . - o gory 1). TOTAL HD e RH PR RU P PE FV OT PARr REPLAcED HO-Handle RH-Rod hangar RM-R..ing main PE-Pumping element F-Fulcrum PR-Pump rod PS-Piston seal FV-Foot valve OT-Other PUMP 36 169 Philippines Laboratory Tests The suction version of the Jetmatic pump was not tested in the CATR Laboratory. However, tests were carried out on the deepwell version, which has the same pumphead mechanism, and the entry for Pump 1 1 has some details which are also relevant to the Jetmatic Suction. In particular, the handle mechanism failed during the endurance test and the gland nut wore badly. General Description The Jetmatic is made in the Philippines to a design similar to that of Kawamoto Pumps of Japan. It is also available as a deepwell pump (Pump 11). The cast iron pumpstand is compact and fits on the protruding end of the suction pipe, which must protrude at least 440mm above ground to prevent the handle touching the ground and to provide clearance for the spout. A discharge valve in the spout allows either free discharge or pressure delivery through a hose or pipe. Manufacture Gumetal and iron foundry work and basic machining are required, with good quality control to ensure interchangeability of spare parts. Suppliers There are several, including Sea Com- mercial Co Inc, Cor. V. Cruz Street, Manila 2806, Philippines. Indicative prices - Feb 1985 Pumpstand and cylinder US$35 FOB Manila 170 PUMP 37 Jetmatic Suction Field Trials Assessment Test conditions The Jetmatic Suction ratings are based on field trials and the Number Head Data r performance of the deepwell of range available . , version in the laboratory, and on Country pumps (meters) (months) J the experience and judgment of __________________________ _ 7 _ ': 7 -Project staff. As a suction pump, Philippines 43 2-6 18 ^ - w * s5-t - [[ it is not suitable for lifts in excess Philippines 43 2-6 18______ _ / of 7 meters, and is also at risk of The Jetmatic pumps suffered many fail- contamination if polluted water is usedforpriming. ures in the field trials. Production quality Discharge Rate was generally poor, so that the low initial water for a family unit or a group of 10-15 The pump is capable of achieving cost of the unit was more than compen- users for up to one year without major a relatively high discharge and sated by the high demand for spare parts. failure. earns a "good" (oo) rating. Failures were occurring within a few If production quality could be imp- Ease of Maintenance weeks of installation, and included broken roved and controlled, and if the design The number of wearing parts handles and crossheads and worn pins. In was altered to include sleeved cylinders, which need regular attention addition, there was constant replacement quality seals, ball race pivots, and quality keeps the rating for village-level of seals worn down by the rough cylinder castings, it should be possible to improve (system A) maintenance down to surface. durability and raise the user group to 'adequate" (o). For maintenance The general conclusion was that the perhaps 50 beneficiaries. Some design systems B and C, the rating is oo. present design and manufacturing stan- improvements have already been made, in Reliability dard of the pump make it suitable for only response to shortcomings encountered The field tests showed that the light use. It might, for instance provide duringthefieldtrials. Jetmatic suffers rapid wear, and the oo rating for reliability at 1.5m3/d reduces to o at 4m3/d. The pump is rated "unsuitable" (-) at 8m3/d. Corrosion Resistance The suction version of the pump earns a o rating for corrosion resistance. Abrasion Resistance Regular replacement of leather cupseals in the field trials resulted from roughness of the cylinder casting. In general, the suction pump has adequate resis- tance to sand pumping and earns a o rating. Manufacturing Needs The Jetmatic Suction is not suitable for manufacture in coun- tries with a low level of industrial development (category 1) beca- use of the need for foundry and machining skills. For categories 2 and 3, the ratings are oo. PUMP 37 171 Thailand Laboratory Tests THE LUCKY WAS NOT TESTED IN THE CATR LABORATORY General Description The Lucky is a simple shallow-well suction pump constructed mainly of cast iron and s;upplied complete with 10 meters of 1-1/2 inch diameter galvanized steel drop pipe fitted with a footvalve. PVC drop pipes can be used as an alternative. The plunger has a large diameter rubber seal, giving a high discharge per stroke. Manufacture The Lucky is widely manufactured in Thailand by small and medium foundries, but its reliability depends on good casting skills and quality control of items such as the handle, fulcrum pins, piston rod guides, etc. Suppliers Available from many foundries throughout Thailand. Indicative prices - Apr 1986 Per unit, including 1 Om of G.I. drop pipe and footvalve US$ 35-40 172 PUMP 38 Lucky Field Trials Assessment Test conditions J - I Test___conditions _____---__A_ The Lucky ratings are based on Number Head Data ithe pump's performance in leng- of range available I thy field trials in Thailand, which pumps (meters) (months) provided enough data for confi- dent judgments about the pump's Thailand 20 2-6 30 capabilities. As a suction pump, the Lucky is restricted to pumping lifts of 7 meters or less. It also The Lucky pumps performed very poorly l requires priming and is therefore in the field, proving quite unsuitable for at risk of contamination if polluted heavy duty operation at the village level. comparison with other suction pumps, it water is used for the purpose. The crosshead system has too does have some disadvantages. Several Discharge Rate many moving parts, which are subject to spanners are needed to take the pump The pump is capable of achieving rapid wear. Though the discharge is high apart, and the need to lift out 10 meters of a high discharge rate and earns a and the pump is therefore popular with 1-1/2 inch diameter galvanized steel drop 'good" (oo) rating under this users when it is working properly, the pipe to service the footvalve precludes heading. frequency of necessary repairs means maintenance by a village caretaker. Maintenan e Needs that its use would have to be restricted to Even if higher production standards fairly simple to mainWtn, but the small user groups. could be achieved, it is unlikely that the needfor several spannersto take As a suction pump, the Lucky is Lucky design would be suitable for high the pumphead apart, and the inherently easy to maintain, though in daily outputs. dificulty in removing the footvalve for servicing make it unsuitable for village-level maintenance (Sys- tem A). For area-mechanic and central maintenance (Systems B and C), the pump eams a oo rating. Reliability The Lucky needed frequent repairs in the field - trials and cannot be recommended for high daily outputs. It is rated "ade- quate" (o) for 4m3/d, and oo for 1.5m3/d. Corrosion Resistance The pump has no special protec- tion against corrosion and so cannot be recommended where groundwater will be corrosive. Abrasion Resistance The rubber seal earns a o rating for abrasion resistance. CAUSES OF ESSENTIAL INTERVENTIONS Manufacturing Needs 5- 2 -30 The pump is widely manufactured 4.5 * -1.75 in Thailand, though to a varying te 4- - . -25 rn quality standard. It would not be _1.50 rr suitable for manufacture in a coun- o 3-5< * t -20 try with a low level of industrial § 3- 1 -1.25 Q- 9 development (Category 1), but is ' 2.5- 1 5 15 given a oo rating for medium or IL 07 high levels of industrial develop- C 1.25- | | ~0.7550 Cm~10 ment (Categories 2 and 3). 1.,- * -1-2 0; o.50~ o.s 0.25 0 0 -0 TOTAL HD F RH PR RV PS PE FV OT PART REPLACED HD-Handle RH-Rod hanger RM-Rising main PE-Pomping element F-Fulcrum PR-Pump rod PS-Piston seal FV-Foot valve OT-Other PUMP 38 173 Bangladesh Laboratory Tests Date tested: 1982 Reported: Project ReportNo. 3 cylinder bore causing rapid wear in the _________________i____I___________ cupseal. L_ _' . t u At the end of the endurance test, the Performance data plunger could not be dismantled because w (typical values) of rusted threads, corrosion of the (typical values) retaining screw prevented removal of the Head (meters) 7 check valve weight from the leather flap, Pumping rate (cycles/min) 30 and there was considerable rust on the Volume/minute (liters) 36 unprotected cast iron of the pump body. Input (wafts) 60 Pivot holes in the handle, pump top and Efficiency (%) 67 connecting rod eye were all noticeably Maximum handle foc ...kgt.. . 4 worn and the pivot axles were also worn, Maximum handle force (kgf) 14 though still serviceable. The check valve l l Leakage of foot valve (mI/min) <1.0 leather flap was deeply indented. The pump failed in one of the side The volume dischargedper stroke impact tests, but proved capable of was about 1.2 liters. withstanding considerable shock to both the body and the handle, which indicates that it is quite robust. The simplicity of Evaluation installation does mean that it has little The two pumps acquired for testing were resistance to abuse, as it is easy to both received in working order, though remove the complete pump from the drop pump tops were loose and in one case the pipe and steal it. Pivot axles and bolts are halves of the plunger were not tightly also easy to remove. screwed together. Many users were pleasantly No installation and mainte- surprised by the performance of the New General Description nance instructions were supplied with the No.6, which contrasted with its somewhat pumps, but a helpful leaflet was supplied crude appearance. It delivered well over a The New No. 6 is a simple and robust on request. Installation is simple and liter of water with each stroke, and the shallow-well suction pump constructed requires only basic tools and skills. The handle movement allowed arms, shoul- almost entirely of cast iron. The piston assembled pump is mounted directly on ders, back and legs to contribute to the uses a molded PVC cupseal and the the drop pipe, which must be securely operating effort. Some users disliked the check valve is a weighted leather flap. The fixed in position. Maintenance is simple roughness of the handle. pumpstand is mounted directly on the and could be carried out by a village The overall conclusion of the suction pipe., which is 1.5 inch galvanized caretaker. Handle pivots need to be oiled laboratory trials was that the New No. 6 is steel or PVC. More than a million units twice weekly, and the manufacturer a very simple, cheap and sturdy pump, but have been installed in Bangladesh. recommends that the piston seal and likely to wear considerably when heavily valve should be replaced yearly. This used. It is well suited to manufacture in Manufacture could be troublesome, as the test pumps developing countries with basic foundry The, pump is manufactured widely in suffered extensive corrosion, skills and has no close tolerances - the Bangladesh and is suitable for manufac- The 4000 hour endurance test was holes for the handle pivot axles are deli- ture in any developing country with basic conducted at 30 strokes per minute and 7 berately drilled oversize to avoid problems foundry skills. It has no fine tolerances. meters head. The original cupseal and of misalignment. plunger valve were badly worn after 1000 As with any suction pump, the New Suppliers hours and were replaced, along with the No. 6 has to be primed and is therefore The pump tested at CATR was supplied by check valve. The replacements lasted the susceptible to contamination if polluted Engineers Wood Steel Industries Ltd, 67 remaining 3000 hours, though the cupseal water is used. A sliding plate on the Tejgaon Industrial Area, Dhaka-8, and plunger valve were badly worn at the connecting rod would be a simple design Bangladesh. There are many more manu- end. Poor performance in the first 1000 improvement, to combat accidental conta- facturers of the New No. 6 in Bangladesh. hours reflected an initial roughness in the mination. Indicative prices - Feb 1985 Price per unit (min. 50 units) US$63 174 PUMP 39 New No. 6 Field trials Assessment In the absence of field trial moni- *% j tw toring, the New No. 6's ratings are based on its performance in 1 7:J the laboratory, and on the expe- rience and judgment of Project staff. As a suction pump, the I -;pX . New No. 6 is not suitable for lifts - = ~~ > : _,^, , ~in excess of 7 meters. It also requires priming and is therefore at - -*,t,_. _ risk of contamination if polluted _ 71 ps*. > -water is used for the purpose. _ . _ o_ _d Discharge Rate The high discharge rate of 36 liters per minute eams the pump a good (oo) rating under this theadng THE NEW NO. 6 PUMP WAS NOT FIELD TESTED BY THE Ease of Maintenance HANDPUMPS PROJECT ~~~~~~~~Repairs are simple to carry out and HANDPUMPS PROJECT require only basic tools, so that the pump qualifies for a 00 ratng under each of the maintenance headings (A. B and C) Reliability Under low usage conditions the pump also eams a 00 rabng for reliability, but for more intensive applications, more frequent repair interventions would be necessary, and the rating drops to "adequate" (0) for 4m31d and to "unsuitable' (-) for 8m; a Corrosion Resistance The pump has no special protec- tion against corrosion and suffered extensively from rusting in the laboratory tests. It cannot there- fore be recommended for situ- alions where groundwater is likely to be corrosive. Abrasion Resistance In general, the pump proved to be reasonably resistant to sand pum- ping in the laboratory. It earns a oo raling for abrasion resistance principally because of the tough plasl'c,sea PVC seal. Manufacturing Needs The New No. 6 is widely made in Bangladesh and is well suited for manufacture in a country with a moderately developed industrial base However, its manufacture requires a basic awareness of qualily control procedures, and it is therefore rated only o for coun- tries with a low level of industrial development (Category 1). PUMP 39 175 Bangladesh Laboratory Tests Date tested: 1983/84 The 4000 hour endurance test was Reported:.Project Report No. 3 carried out at 19 cycles per minute and a ______________O___//_________X__ head of 7 meters. No breakdowns occur- Performance ' (typical ..... ._red, though the check valve was replaced D <,// z o s Performnancedata (typical after 1000 hours as inspection revealed values) - 54mm cylinder that the rubber flap valve was loose. Some joints in the drop pipe were found to be Head (meters) 7 leaking during the test, and the threaded Pumping rate (cycles/min) 15 joints were replaced with cement joints. As Volume/minute (liters) 27 well as reducing performance, leaking . \ \(@Ea iInput (watts) 48 joints caused a rapid loss of prime. \ ( - Efficiency (%) 64 Small amounts of surface rust were Maximum handle force (kgf) 20 found on the check valve and plunger Leakageoffootvalve(mVmin) High body fixings and there was slight pitting of the plunger rod, but all parts remained The volume dischargedperstroke serviceable. The cylinder bore was worn at \ 0 6g)was about 1.8 liters. the end of the test, resulting in a 2mm step in the bore at the end of the swept stroke. The volume delivered per stroke was down on the original performance test, but still Evaluation well over one liter. General Description The sample pumps were delivered by User reaction was generally favor- hand, so no judgment can be made on the able, once users were instructed in the The Rower is a high-capacity low-lift pump packaging arrangements. appropriate method of operation. Only designed primarily for irrigation. The Engineering drawings were supplied small children found the pump difficult to operator pulls directly on the plunger rod with the test samples, and these con- use. Everyone liked the very high dis- by means of a T-bar handle, and the angle tained useful information but would not be charge, though some objected to gefting is convenient for operation from a sitting suitable as an alternative to installation wet when water spurted out of the pump at position using a rowing action. The and maintenance instructions. However, the start of the return stroke. The lack of cylinder is an extruded uPVC tube with installation of the Rower pump should an upper stop caused some problems, heat-swaged ends and the aluminum be very easy, particularly if plastic pipe is with some stronger users pulling the piston is fitted with a leather cup washer used. The most important tool may well be plunger right out of the cylinder. and flap valves cut from tire inner tubes. a spade or shovel to construct the earth The impact test was not applied, as Several different sizes are available. bank. Care is needed to achieve airtight the Rower is intended to be protected The pump is fitted with an aluminum joints in the drop pipe, as any leaks will against such eventualities. The handle surge chamber, and is normally embedded significantly affect the efficiency of the can be distorted quite easily, but is in earth for support and protection, or may pump. equally easy to straighten. be supported by a smaller earth bank and Maintenance too is very straight- The overall conclusion of the labora- protected by strips of bamboo around the forward, and requires only the simplest tory trials was that the Rower is a commen- cylinder. hand tools. The Rower is a true VLOM dably simple pump, easy to install, pump, though the need for priming intro- maintain and repair. Its main application is Manufacture duces a pollution risk when it is used for likely to be low-lift irrigation, as conta- The pump was designed for manufacture drinking water. The pump achieves a high mination of drinking water is almost in a developing country and most compo- delivery on each stroke, and its inevitable. Performance falls off with time, nents are easy to make. Some skill is discharge of 27 liters per minute at 15 because of wear, but all wearing parts are required in heat-forming the uPVC tube cycles per minute is also high. cheap and easy to replace. and spinning the surge chamber, and care is needed in machining. Suppliers Mirpur Agricultural Workshop Training School Mirpur Section 12, Dhaka, Bangladesh. SWS Filtration in the UK have also developed versions of the Rower pump. Indicative prices - Jun 1985 Per 2in. pump with screen and 7.6 meters of drop pipe US$ 30-35 Extra drop pipe per 0.76m US$ 4.00 176 PUMP 40 Rower Field Trials Assessment iiiEII1V;- i The Rower pump ratings are based on performance in the tab- -~ .9 oratory tests and on experience _3 " '- -- -and judgment of Project staff. The - = ~~Rower was developod prindcpally '.'A * as an irtigation pump, and produces a high discharge. As a suction pump, it is not suitable for pumping lifts in excess ot 1 _ * >, S 7 meters. It also requires priming and is therefore at 'risk of ^i.-;C-,.-' _ _ ffi contamination if polluted water is used for the purpose. DXIscharge Rate The discharge rate of 27 liters per minute at a pumping rate of 15 THE ROWER HAS NOT BEEN FIELD TESTED UNDER cycles per minute declines as THE HANDPUMPS PROJECT, BUT MANY ROWER wear takes place in the PVC cylinder, but remains high enough PUMPS HAVE BEEN OBSERVED IN USE IN BANGLADESH. to justify the pumps 'good" (Soo) rating. PROJECT STAFF COMMENT THAT THE ROWER IS A Ease of Maintenance TRUE VLOM PUMP, WHICH SETS A STANDARD FOR Practically no tools are needed for maintenance and the pump earns DESIGNERS IN A RANGE OF IMPORTANT PARAMETERS: a oo rating under each mainte- nance system (A, B and C). LOW COST Reliability EASY SERVICEABILITY The reliability rating is also 00, for HIGH CAPACITY outputs up, to 4M31d, as the -repairs which are necessary can EASE OF MANUFACTURE be carried out very quickly and easily. The rating drops to THE ROWER IS IDEAL FOR SMALL PLOT IRRIGATION "adequates f8 ) When daily output UNDER LOW LIFT CONDITIONS IN MOST DEVELOPING Corrosion Resistance COUNTRIES. Though small amounts of corro- sion have been detected both in the laboratory and in the field in Bangladesh, they have not been extensive enough to impair the pump's performance, and should notI be a problem unless the-- groundwater is highly corrosive. The Rower is therefore rated O. Abrasion Resistance The Rower, design allows it to pump sand-laden water without difficulty, but the wear of the cylinder walls will be accelerated if sand Is present regularly, and the pump is therefore given a 0 rating for abrasion resistance. Manufacturing Needs The Rower has been designed for cheap and simple manufacture in a developing country with- a low industrial 'base. It earns a 00 rating under each category of manufacturing capability. PUMP 40 177 Laboratory Tests THE SYB-100 WAS NOT TESTED IN THE CATR LABORATORY General Description The SYB-100 is a simple shallow-well suction pump constructed mainly of cast iron. The handle and pumprod pivots are fitted with ball races. Plunger and check valves are rubber flaps and rubber is also used for the plunger seal which moves in a honed cylinder bore. Manufacture The pump is manufactured to a high standard in China, under good quality control of casting and with first class machining. Suppliers Changsha County Light Industrial Plant, Hunan, People's Republic of China. Indicative prices - May 1986 Per unit US$ 30-40 178 PUMP 41 Field Trials Assessment Test conditions - Test conditions ' The SYB-100 ratings are based Number Head Data -'b primarily on the pump's perfor-- of range available mance in field trials in China and of ran(meters) (months) to a lesser extent on the limited experience in Papua New Guinea. China 85* 1-6 24w ,This provided enough data for con- China 85- 1-6 24 " t R --+; ,ts , ^s,, t~~~~ident assessrnent of the purnp's Papua New ^ ^ ~ *t _ -capabilities. As a suction pump, Guinea 10 2-7 12 pthe SYB-100 is restricted to D r , _ _ ~~~~~~~~~~pumping lifts of 7 meters or less. *20 of the discontinued SYB-80 were also It also requires priming and is tested. therefore susceptible to contami- mance to predict that it could reliably nation if polluted water is used for The China field trials involved large num- serve up to 100 users over two years the purpose. bers of prototype suction pumps, many of without excessive failures. The standard Discharge Rate which have been discontinued as a result of village-level maintenance in China is The pump is capable of delivering of their performance in the field trials. The high in comparison with most developing a high discharge and earns a SYB-100 is the exception, having proved countries, and in China, the SYB-100 is good (oo)rating. both popular and reliable. well suited for village-level maintenance. Ease of Maintenance The trials were conducted in Chang- The quality of manufacture of the With the standard of village-level sha (Hunan Province) where the pump is SYB-100 was high, and the pump is well maintenance available in China, manufactured. It must be remembered designed foreconomic replacementof low- the pump would be readily ser- that there are many millions of suction cost components (though this may not be viced by a village caretaker. In handpumps in use in China, and they readilyreplicableinothercountries). with lower skill levels available in generally operate for only short periods The pump design has been improved most villages, the rating under each day, serving just one family or a as a result of the Project experiences, and maintenance System A is ade- small user group. The same kind of ope- the SYB-100 is becoming increasingly quaten (o)" rating conditions also apply in Papua New popular in the country. Some 17,000 units Reliability Guinea. Nevertheless, the Project were ordered for one province, with The SYB-100 proved highly reli- collected enough data on the pump perfor- another 10,000 in preparation. able for moderate daily outputs in China and Papua New Guinea, and earns a oo rating for dis- charges up to 4m3/d, dropping to o for 8m/d. Corrosion Resistance Though the pump has no special provision for combatting corro- sion, little sign of corrosion emer- ged from the field trials, earning a o rating. Abrasion Resistance CAUSES OF ESSENTIAL INTERVENTIONS The honed cylinder bore and I -1 2 rubber cupseals resulted in long 0.9 0 seal life, and justify a oo rating o.s s ~ ~~~~~~~~~~~~~~~~ under this heading. Z 0.8 -0.3 m Manufacturing Needs 1.5 C ultyi hiai °0.7 - Z Manufacturing quality in China is \ 0.6 | -0.6 t zhigh, and the SYB-100 design would suit manufacture in ~0.5- 0.5 _ l s -l > countries with moderate or highly Lz 0.4 _ -0.4 < odeveloped industrial bases 0.3 0.X (Categories 2 and 3), for which 9 0.2 0.2 -. the pump scores a oo rating. The 0 i a skill levels and quality control needed to ensure reliable perfor- 0 0 -0 mance make it unsuitable for TOTAL HD rRH P'R Riii PS PE FV OT PART REPLACED manufacture in developing coun- LO CHANGSHA = JINCHENG tries with low levels of industrial HD-Handle RH-Rod hanger RM-R,sing ma,n PE-Pump.ng element development. F-Fulcrum PR-Pump rod PS-Piston seal FV-Foot salve OT-Other ._ . PUMP 41 179 India Laboratory Tests THE WASP PUMP WAS NOT TESTED IN THE CATR LABORATORY General Description The Wasp is a conventional shallow well suction pump constructed almost entirely of cast iron. The cylinder is machined in the lower part of the pump body. The cast iron piston is fitted with a single leather cup seal and gunmetal valve. The check valve is also of gunmetal and is held in a cast iron cage. The stain- less steel pumprod passes through a sliding brass plate covering the slot in the pumpstand top-plate and so reducing the contamination risk. Bars in the spout prevent sticks or stones from being pushed into the pump. The handle has a low starting position. Manufacture The Wasp can be readily manufactured in a country with basic foundry skills plus basic machining and leather crafting, though careful quality control is needed with cast iron components. Suppliers Shukla-Manseta Industries Private Ltd, 248 Ambalal Doshi Marg, Bombay 400023, India. Indicative prices - 1983 Per unit, excluding suction pipe US$185 CIFColombo 180 PUMP 42 Wasp Field Trials Test conditions Assessment Number Head Data _ - F . The Wasp ratings are based on the of range available pump's performance in field trials Country pumps (meters) (months) in Sri Lanka. As a suction pump, s w _ f fi _ ~~~~~~~the Wasp is not suitable for lifts in Sri Lanka 25 2.8*-5.0 20 excess of 7 meters. It also requ- ________________________________ _ _ires priming and is therefore at risk * Average head f - - of contamination if polluted water * 1 \ ~is used for the purpose. The Wasp is a derivative of the Maya No. 6 l _, Discharge Rate cast iron suction pump design common on - A discharge rate of 26.5 liters per the Indian subcontinent. Its drive mecha- . minute at 30 strokes per minute nism is exposed to dust and weathering. gives the pump a "good, (oo) No literature was supplied with the rating. pumps, but only basic tools and skills are cupseal can be expected to last from 8 to Ease of Maintenance required for installation. On average, three 10 months, depending on the usage and Maintenance is simple, requiring workers completed installation in half an theroughnessofthecylinder. only a single spanner and hour on protected dug wells in Sri Lanka. Plunger valves and check valves screwdriver, but frequent lubri- The pump is attached to anchor bolts were noticeably worn after 18 months, cation of bushes is needed. The embedded in the concrete cover slab of both on their circumferences and on their pump therefore earns a "good" (oo) the well and must be set at least 300mm faces. There was no significant wear on rating for maintenance Systems B above the well head to provide a comfor- the cylinders. Pivot bushes generally wore and C, reducing to "adequate" (o) table standing position for operation. The out within a year and pivot pins were worn for System A (village-level). handle can be set at a right angle to the but serviceable. In all, three handles and Reliability spout to avoid the need for the operator to two fulcrum plates broke during the trials. The reliability rating is oo for low stand on the well cover slab. The Wasp delivers a respectable usage - similar to conditions in Servicing of all parts is easy, using a 26.5 liters/min at 30 strokes/min, but the the Sri Lanka field trials - but single adjustable spanner and a screw- some users dislike the operating action reduces to o for 4m3/d and to driver. All bolts are the same size, and are because of the low starting point of the "unsuitable" for 8m3/d, where the set in slots to prevent rotation of the bolt handle. higher intensity of use would head. Frequent lubrication of the exposed The use of brass with ferrous metals require too frequent maintenance axles and bushes was found to be led to galvanic corrosion, and there were interventions. essential, and even then bearing failure complaints about taste and/or color of the Corrosion Resistance accounted for half of all breakdowns. water at 15 of the 25 test sites. After 18 months in the field, the The pumps were only lightly used and As with any suction pump, the Wasp inner pump body, pumprod, plun- an average of 2.1 interventions were nee- has to be primed, and is therefore ger and check valve were heavily ded per pump per year to repair break- susceptible to contamination if polluted rusted, and the Wasp cannot downs or correct poor performance, the water is used for the purpose. In the Sri therefore be recommended for use main items being bearings and seals. In Lanka trials it compared unfavorably with where water is corrosive. all, 23 leather cupseals were changed on the Inalsa Suction pump in terms of cost, Abrasion Resistance the 25 test pumps during the first 18 reliability, ease of maintenance, and The leather cupseals failed regu- months of testing, and it seems that a resistance to abuse and contamination. larly during the field trials, and would be even more susceptible in CAUSES OF ESSENTIAL INTERVENTIONS sand-laden water. The pump is 5 3 60 therefore given only a o rating. 4.5- Manufacturing Needs M 4.52.. 50 The Wasp is made in India and is ^ 4_ - -2.5 -S0 g suitable for manufacture in any 3.5- - -2 40 developing country with basic 9 3- - . -2 < ' -4° 8 foundry, machining and leather craft skills. The degree of quality 2.5- 1.5 -30 ~~~~~~~~~~~~control needed results in a - > 2- - - i 2 rating for countries with a low-level i 1.5- 1 -20 industrial base, but a oo rating for 1- ~ ~ ~ ~ ~ ~ ~ ~~~~. 0other countries. 0.5 0 JE0 0 TOTAL HD F RH PR RU PS PE FV OT PART REPLACED HODHandle RH-Rod hanger RM-R.sing main PE-Pumping element F-Fulcrum PR-Pump rod PS-Piston seal FV-Foot valve OT-Other PUMP 42 181 Annex 1 3 f V ng Pumprs l>(a"b, Tested This Annex contains brief details of 17 additional pumps restricted to manufacturers' published data and obser- which have come to the attention of Project staff during vations by Project field staff, so that it has not been the course of the field trials. They were not included in possible to "rate" the pumps in the same way as those the laboratory or field trials organized by the Project (or included in the Pump Selection Tables in Chapter 5. were included too late for results to be available for this Analysts wishing to include particular pumps from document). this Annex in the selection procedure described in The pumps may be of special interest because they Chapters 5 and 6 should first seek fuller details from the involve unique features or promising design concepts, or manufacturer, and, where possible, obtain field expe- because they have received wide publicity, or because rience from existing users. The pumps included in the they are known to be used by large numbers of people in Annex are tabulated below. particular regions. The information available is generally Pump Country of manufacture Known installations Page Abi-MN Cote d'lvoire Cote d'lvoire 184 Aquamont United Kingdom Burkina Faso, Cameroon, Malawi, Zambia 184 Atlas-Copco Sweden Ghana 184 Bourga Cote d'lvoire, France, Niger Niger 184 Bucket Zimbabwe Sierra Leone, Zimbabwe 185 Bush Zimbabwe Zimbabwe 185 Grundfos Denmark Sudan 186 Nsimbi Zimbabwe Zimbabwe 186 Pek Canada Bolivia, Cote d'lvoire, Kenya, Senegal 186 Pulsa Italy Benin, Burkina Faso 187 Puno Peru Bolivia, Peru 187 Rope ("Soga") Peru, Nicaragua Bolivia, Nicaragua, Peru 188 Sholapur India India 189 Swedpump Sweden Central African Rep., Ghana, Sudan 189 UPM France Burkina Faso, Niger 189 Wavin The Netherlands Bolivia, India, Kenya, Malawi, Tanzania 190 Wearmaster United Kingdom Not known 190 183 pool. Two head assemblies are available: steel, and is attached to a wire-reinforced Abi-MN Cote d'lvoire the MK 1 standard drive, which provides a rubber hose pumping element. Recomm- positive pumprod return; and the MK 2, a ended maximum installation depth is 30 The Abi-MN is a conventional recipro- chain drive version. Above ground, the meters. Samples with stainless steel cating piston pump with a lever handle. pumpstand is galvanized or painted and The cylinder is made of brass, and the sealed taper roller bearings are fitted to standard version is equipped with galva- the fulcrum and hanger. Galvanized iron nized rods and rising mains. Most of the or ABS rising main is used with 10mm _ 0O above-ground components are identical stainless steel pumprods incorporating to those of the Abi-ASM pump (Pump 01 in PTFE centralizers. A PTFE lined glass- the Handpump Compendium), except for reinforced epoxy resin cylinder is prov- ided, employing nitrile seals and claimed to have both low wear and friction, making pumping from lifts up to 90 metres a prac- tical possibility. Pumps have been sent to Cameroon, Malawi, Zambia and Burkina ; below-ground components are being sent to Ghana for field testing and CATR laboratory tests of this pump started at the end of 1986. Model 122 uses the same above- ground pumpstand, rising main and pump- rods as the 111 but uses a conventional stainless steel cylinder below ground. Manufacturer Atlas Copco Energy AB, S- 10523 Stockholm, Sweden. the connections to the rising main and rod, Li the lack of a hydraulic drive cylinder, and Bourga Cote d'Ivoire, a slightly different handle. An earlier Faso for limited field trials and will be France, Niger model with the same name (Abi-MN) had tested in the CATR Laboratory in the near different above-ground components, and future. This is a reciprocating piston pump ope- was generally liked by users because of More information: E.T.C. Aquaservice, rated with a lever handle, based on its easy operation and reasonable dis- Cunard Building, Liverpool, L3 1HR, conventional handpump design concepts. charge rate, although repairs were United Kingdom. The standard versions are equipped with difficult. The most significant difference galvanized steel rising mains and rods, between the old and new above-ground Atlas-Copco Sweden and cylinders made of brass. The handles components of the Abi-MN is the change r are counterbalanced to ease operation. from ball bearings to plastic bearings. The Three models are available, which the plastic bearings, which have been stan- The Atlas Copco model 111 is a Swedish- manufacturer specifies as follows: dardized for both the Abi-ASM and the Abi- made pump with a galvanized welded * the Model 1000 has a 70-mm piston, MN pumps, have the advantage of being pumpstand assembly. The handle fulcrum and is specified for one-person easily replaceable. bearing has a special rubber element (adult) operation at lifts up to 45 Manufacturer: Abidjan Industrie, 01 BP which purports to eliminate wear problems meters, and two-person (two adults 343, Abidjan, 01 Cote d'lvoire. evident in conventional bearing systems. or 3-4 children) operation at lifts up A connecting belt between the end of the to90m; Aquamont United Kingdom handle and the pumprods is designed to * the Model 2000 has a 1 00-mm piston, avoid the wear which occurs with chain and is specified for one-person ope- This pump is manufactured in the UK and and quadrant operation. The SW-system ration at lifts up to 22.5m, and two- marketed by E.T.C. Aquaservice of Liver- of rising main and pumprod is in stainless person operation at lifts upto45m; 184 * the Model 3000 has a 120-mm has responded to these reports by Bcaring Windlass Chain piston, and is specified for one- modifying several components. camp person operation at lifts up to 15m, The assessment of this pump can be and two-person operation up to 30m. summarized as follows: users like the high Wooden volume flow; it is robust; it is suitable for bearing The handle has a T-bar to facilitate local manufacture in some developing Bucket- operation by more than one person and to countries; access to below-ground com- allow the user to apply force at the ponents for repair is difficult and the pump therefore cannot be classifed as Water handlc , ,# VLOM (Village Level Operation and discharge -,- ,# \. Maintenance). unit Manufacturers: The pump was originally Steel head Steelcap manufactured in France by G. Bourrier, 5, Concrete Rue Elisee-Reclus, 93300 Aubervilliers, , d , ' France. Later, production was begun by the following two manufacturers in Cote Spout- d'lvoire and Niger (in at least some cases - . W . I Tee handle pumps have been assembled in Niger with components made in Cote d'lvoire and France): Ateliers de Construction Electro- Mecanique de C6te d'lvoire (ACEM-CI), Windlass BA.-522, Abidjan 15, Republique de C6te support footing d'lvoire; SEEE (Societe d'Etudes et Entreprise d'Equipment), BP 11.986, Niamey, Niger, Bucket Zimbabwe The Bucket Pump is an improved version of the traditional rope and bucket connected to a windlass. However, the particularly well suited to VLOM (Village Bucket Pump is suitable for installation in Level Operation and Maintenance). A narrow-diameter wells, whereas the major disadvantage of the Bucket Pump traditional arrangement requires a wide- is the low rate at which water can be diameter well. The Bucket Pump is extracted from the well, making it more of essentially a long narrow bucket with a a family or multi-family pump and not suit- large check valve at its bottom, which able for use by larger numbers of people. allows water to enter it from below as it is Another disadvantage is that some conta- extreme end of the handle where the submerged, but which does not allow the mination maytake place. maximum mechanical advantage can be water to escape as the bucket is lifted up The Bucket Pump is made by local achieved. Also, the handle has a counter the well (this is analogous to the piston shops in Zimbabwe and Sierra Leone. weight which can be adapted for the lift at valve on a conventional handpump). Its More information can be found in a which the pump is to be used. The pump own weight is sufficient to submerge it pamphlet describing the pump, entitled has a high discharge rate, although this when lowered into the well, and, when full, Pump Handout No.1: The Zimbabwe is accompanied by the need for a it is lifted by turning the windlass, thus Bucket Pump, available from the Blair relatively high force to be applied to the lifting the connecting chain and pulling the Research laboratory, Box 8105, handle. However, the facility of having bucket up. A simple "water discharger" is Causeway, Harare, Zimbabwe. multi-person operation compensates for attached to a post, and, when the bucket the high force required, and users like the is set on it by hand, this opens the check high discharge rate. The Project has valve and discharges into a waiting con- Bush Zimbabwe field tested a few of these pumps in Niger tainer which the user has placed below. - 3 of Model 2000, and 1 of Model 3000. When compared to the traditional rope These have been intensively used during and bucket, it has, in addition to the ability The Bush pump, a reciprocating deep- well 22 months of field data collection, and to be used with drilled wells, the advan- force pump, was originally designed and have performed well. Although the small tage of decreasing the likelihood of conta- installed in the early 1930's in Zimbabwe. numbers of each model that were tested minating the well water. This is because The pump is still used extensively in the limits the statistical significance of the the bucket is not normally set on the country, with one estimate placing the field data, the following may nonetheless ground where it could pick up contamin- number of pumps installed at 10,000 provide a rough indication of repair ation before being lowered into the well, units. Since then, it has appeared in requirements. as commonly happens when personal various forms throughout East Africa. The average rate of repair or main- buckets are used with wide-diameter The pump design has no exacting tole- tenance interventions has been 1.2 per wells. Also, only a small lid is required to rances and it can be erected by reason- year for each pump. The majority of cover the well when it is not being used. ably well trained persons using basic repairs were required due to defects on Compared with most other hand- tools. The original pumpstand column was footvalves (27%), pumprods (18%), pumps, the Bucket Pump has the advan- made of 6-inch borehole casing, while handles (9%), fulcrums (9%), and pum- tages that it is extremely simple to manu- later models used 5-inch casing or black ping elements (9%). The manufacturer facture, operate, and maintain, and is iron pipe. The pumpstand column is set in 185 results are reported in Handpumps Project Report No. 4. /*1 0 \ Additional information: Office of the Hardwood H Provincial Water Engineer, Ministry of bearing Handle Energy, Water Resources and Develop- -Guide pipe block marely ment, P.O. Box 566, Bulawayo, Pump rod 3 m long) Zimbabwe. connecting link , T___ _ 7 link Grundfos Denmark The distinguishing features of this pump 4 I are the stainless steel cylinder and piston, which are designed to provide corrosion resistance, strength, and effi- cient operation. These pumping elements well can be connected to a wide variety of casing makes of above-ground components, inc- Rising main ii luding the Maldev type pumphead (Pump 14 in the Handpump Compendium), which W i can be either locally produced or pur- pumproct Pump rod chasedpfrom Grundfos. Piston If total corrosion resistance is required for all below-ground elements, Cylinder Grundfos can supply stainless steel rising Valve main and pumprods, although this will increase the cost of the unit. Aside from the use of stainless steel, with rubber seals, the pumping element is Strainer fairly conventional in design, with a 2.5 inch diameter cylinder connected to 1-1/4 latest design featuring a plastic guide inch rising main. When connected to a bushforthehandletube. Maldev pumphead and subjected to an Additional information: Lutheran World a concrete foundation block that also endurance test at the Consumers' Service, Attn. Rev. Wolfgang Lauer, encompasses the borehole casing.The Association Testing and Research (CATR) P.O. Box 988, Harare, Zimbabwe. handle is made from 2-inch galvanized laboratory in the U.K., the pumping steel pipe and is typically 10 to 12 feet elements exhibited high efficiency, high (3.0 to 3.7m) long with a single bend. In discharge rates, and very little wear of Pek Canada this way the upward travel of the piston is the piston seal. They were tested at lifts limited by the handle contacting the of 25 and 45 meters. ground. Manufacture of the pumping ele- The PEK pump is a direct action hand- Mechanical advantages of as much ments requires stainless steel fabrication pump, using an innovative design and as 12 to 1 allow use of a 3 inch cylinder techniques and is not suitable for most several plastic materials. It has a hollow even at high pumping lifts. An oil-soaked developing countries. However, the rod, and in 1985 was offered with two hardwood bearing block is used at the Maldev pumphead, or other pumpheads to different cylinder diameters: Model P fulcrum and rod hanger. Four holes are which the pumping elements can be conn- rated by the manufacturer for a maximum drilled, two of which provide a backup pair ected, can be locally produced in many pumping head of 25 meters; and Model G to extend the life of the blocks. Pins are developing countries. for up to 50 meters. Those tested by the made from 1-inch pipe. The first of these units were installed Handpumps Project were all of Model P The relatively large size of the pump in the Sudan and other East African (25m). components serves the purpose of mini- countries in early 1986, but it is still too Modifications were made by the mizing wear rates of the wooden bearing soon to have meaningful data concerning manufacturer immediately following the blocks. A 0.9m-long connecting link is theirenduranceunderfieldconditions. laboratory test and on other occasions. used to minimize the lateral movement of Manufacturer: Grundfos International a/s, Consequently, there are slight variations the pump rod in its wooden guide bush. DK-8850 Bjerringbro, Denmark. among PEK pumps sent to different coun- Also, a 3/4 inch sleeve is placed over the __ tries for field trials. However, these modifi- pumprod. Its larger diameter reduces cations did not result in significant chan- wear on the guide bush. Nsimbi Zimbabwe ges in performance. Further changes The Handpumps Project has no made in 1986 in response to reports of information on water delivery rates or This is a direct action pump manufactured field problems have not been evaluated by repair frequencies for this pump. As with and installed in Zimbabwe by the Lutheran the Project at the time of preparation of other closed cylinder designs, replace- World Federation. It uses locally manufac- this report. ment of seals and repair of other down- tured PVC for the rising main and pump- Manufacture involves casting in hole components are difficult and require rod. The footvalve is a unit obtained polyurethane and simple steel fabrication lifting tackle. locally. The plunger uses a simple disc techniques. Complex molding tools are A version of the Bush Pump, known valve and an imported, double-acting required, as well as experience in the use as the Kenya Atlas-Copco, was tested in rubber seal. The head consists largely of of polyurethane and a supply of raw the CATR Laboratory in 1981, and the standard pipe sections and fittings, the material. It is therefore unlikely to be 186 suitable for manufacture in the majority of ration; F. The piston seal wears too advantageous. The Handpumps Project developing countries. rapidly. staff have periodically inspected three Complete for installation at 30 The pump has many interesting fea- Pulsa pumps in Burkina Faso since meters depth when 50 units are ordered, tures and is a break from traditional ideas October 1983, and also made a single the ex-factory price in February 1985 was of pump design (even of direct action limited inspection of five Pulsa pumps in US$465each. pumps). However, good innovative thin- Benin in 1984. However, full-scale moni- The CATR laboratory evaluation king is let down by several weak points. toring of a large sample of Pulsa pumps concluded that the PEK is simple and In spite of its severe shortcomings, it is lightweight, and therefore very easy to the judgment of the Project that the PEK install and to maintain at village level. pump has the potential to be developed The rate of delivery is low and likely to fall into a good VLOM product, but would Spout substantially. In laboratory testing the require some major changes. It has the mechanical efficiency at a 25 meter basic advantages of being lightweight, pumping lift was initially measured at 60%. having a minimum number of wearing However, at the end of the 4000 hour parts, requiring a minimum number of endurance test it had decreased to 13% tools for installation, and having most of as a result of wear. The pumprods were its components made from long-life mate- found to be inadequately sealed, and the rials. Also, if produced in large quantities, ingress of water will dramatically affect the Project believes it could be sold for a the operating characteristics. The pump-- modest price. stand is tough and wear-resistant, but The manufacturer is responding to . extensive use of polyurethane may make the Project's reports of shortcomings of the PEK unsuitable for manufacture in the pump, by producing a modified l developing countries. version which the Project has not yet The Project did limited field testing of evaluated. 25 PEK pumps in 5 countries. Due to Manufacturer: Produits pour l'Exhaure de excessive operational problems, pumps l'Eau Kaine Ltee, 1106 Claire Crescent, in all countries except Bolivia were with- Lachine, Quebec, H8S 1 Al, Canada. drwnshrty ftrintalaio,*n was not undertaken. Furthermore, the tnerefore there are no statistincal at manufacturer has made some changes rulsa Italy since these pumps were installed, so the observations of the Project are no more U The Pulsa 3 is a lever-operated deepwell than indicative and not a final "verdict." i ~~~~~The Pulsa 3 is a lever-operated deepwell A major drawback of using this pump handpump which works via a principle of for community water supply is its low oscillating water columns. The connection discharge rate. In Burkina Faso, it was between the above-ground and downhole found that when operated at 50 strokes elements of the pump is via a single hose, per minute the discharge ranges from 2 to without rods. It comprises two basic ele- 9 liters per minute. In Benin, the ments: an upper part made of stainless discharge rate, when operated by local steel situated above ground, containing a women and children who were expe- plunger actioned by a lever handle; and a rienced with it and seemed to be lower part, submerged in the water, which operating it optimally, was only about 50 is an elastic element closed at the bottom to 75% of what would be expected with by a check valve with a filter. The two are other pumps such as the India Mark II, joined by a flexible hose. The cylinder at which is installed in nearby communities. the bottom acts like a diaphragm, with the The pump is also difficult to operate ___ _ n internal volume of water becoming larger efficiently, although as users become II when it is under increased hydraulic accustomed to the rhythmic operation pressure, via the compression of flexible required, this becomes less troublesome. H5; balls that are situated in the cylinder. Several breakdowns occurred during the _J iMiiIn some ways, it is analogous to the first 2.5 years that the pumps in Burkina better-known Vergnet pump (Pump 21 in Faso were visited. the Handpump Compendium), insofar as Manufacturer: Fluxinos, Via Genova 10, both have flexible hoses and operate via 58100 Grosseto, Italy. hydraulic pressure without conventional pumprods. However, efficient use of the b Pulsa is very dependent on the speed Puno Peru and rhythm with which it is operated. The design concept facilitates This is a conventional reciprocating hand- installation and access to below-ground pump with a lever handle, which was repair frequencies. The most noteworthy components. Installation is unaffected by developed specifically for production in shortcomings of the PEK observed in the curves in the borehole because of the small local machine shops. The Puno limited field testing included: A. Operation flexible hose used for the rising main, and handpump is produced in the Department is exhausting work; B. Discharge rates the lack of conventional pumprods. The of Puno, Peru, where it was developed are very low; C. Users dislike the pump; manufacturer also provides modified under a Peruvian project with support from D. Manufacturing quality control has been versions which allow installation of several the Netherlands.The first prototype was inadequate; E. Installation requires pumps on the same borehole, which under installed in 1981, but most Puno pumps excessive care to ensure proper ope- certain circumstances can be very have been installed only in the past 187 couple of years.The Handpumps Project models are sold without the PVC lining, "So " P has included 15 Puno pumps in its and have very rough cylinder walls which Rope (Soga") eru, Bolivian field trials. Testing began too will probably result in short life for the Nicaragua recently to provide meaningful data on piston seals). As of 1985, quality control frequency of repairs, but some worthwhile was assured by inspections undertaken The Rope Pump described here is manu- observations have been made.These by a local entity supported by the Puno factured in Peru, where it is known as the observations are presented below, and Departmental Development Corporation "Soga Handpump." A similar pump, called are based on both the experience in (CORPUNO) and GTZ of the Federal the "Mecate Pump", is manufactured in Bolivia and on short visits to Puno made Republic of Germany. However, some Nicaragua. The Rope Handpump is essen- in 1985 and 1986 by the Project's Bolivian local shops in Puno were bypassing this tially a very low lift pump with a high Country Monitoring Engineer. control, and selling apparently inferior discharge rate that may be suitable for This pump was originally designed pumps to the public. small-scale irrigation. The Peruvian manu- with the intention of lifting water from as The price is modest, with single units facturer states that it is adequate for much as 25 meters, but it is now recomm- sold in Puno quoted in mid-1985 at the pumping lifts up to 6 meters, but field ended by its producers for a maximum lift equivalent of US$142, complete for instal- observations indicate that above 4 meters of only 15 meters, and in practice it is lationata6mcylindersetting. pumping is difficult. In Nicaragua, there used where the average lift is about 9 The pumphead has an interesting has been experimentation with a smaller meters. An advantage is its suitability for feature shared with the Kenyan-made diameter rising main which allows use with local manufacture with no imported parts, Afridev (Pump 02 in the Handpump higher lifts, but with a lower discharge Compendium): an internal overflow return rate. The pump has a nylon cord with a pipe assures that, if a user (such as a series of rubber discs placed along it. As child playing) plugs the discharge spout illustrated in the drawing presented here, or if the user pumps so rapidly that not all the cord is pulled up through a PVC rising of the water can discharge through the main, lifting the column of water in the spout, then the excess water will flow rising main into a receptacle, from where it back into the well via the overflow pipe flows out of the discharge spout. The cord instead of backing up into the upper part is installed as a long loop and conti- of the pumphead, where it could acce- nuously returns down the well and back lerate corrosion. up the rising main. The pump is operated Installation is fairly simple, espe- by rotating handles on either side of the cially for shallow settings, where the wheel. The rope and discs move through length of rising main is short. However, the grooved rim of the wheel as it is maintenance is complicated by the fact rotated. The rim of the wheel is made from that access to the piston requires that all an automobile tire turned inside out. below-ground components be lifted out of The Project has begun to field test the well. This is made particularly difficult the Rope Pump in Bolivia, but it is still too by the poor design of the flange conn- early to provide a complete assessment. ection between the rising main and the However, it is already apparent that the pumpstand, which requires awkward hand- discharge rate is particularly high. For ling, while lifting the rising main whose instance, it was observed that when weight is increased by the water. The pumphead seems to be robust, and is ergonomically comfortable to use. . One concern with the latest model of this pump relates to the bushings for the fulcrum and rodhanger, which are PVC, / cut from standard pipe stock, against - I' steel. The wide diameter should help prolong the life of this component, but local sand-storms may result in sand and the majority of parts are "off-the-shelf" becoming embedded in the PVC, which - items found in the medium-sized town of would then act like sandpaper against the ) |( Puno. Manufacture does not require steel pins. This could result in accele- 4 K extremely precise machining or other rated wear of the pins, which are much difficult operations. Manufacture is said to more expensive than the plastic. I be economical in quantities of as few as The discharge rate is good. For 25 pumps, and there are several shops in instance, in a location where the lift was Puno which produce the pump. about 13 meters, a local man was mea- Some of the materials used in its sured to pump 47 liters per minute (he construction are highly susceptible to filled a 20-liter bucket in 26 seconds). The corrosion, such as the 3/8-inch diameter high discharge rate may relate to the T- construction reinforcing steel used for the bar at the end of the handle, combined I pumprod. The galvanized steel rising main with an appropriate mechanical advan- is also susceptible to corrosion. However, tage for this lift, resulting in good other components were designed specifi- ergonomics. cally to resist corrosion, such as the Supplier: Centro de Asesoria Para Bom- bronze piston and the cast iron cylinder beo de Agua, Convenio Peru-Alemania, with a PVC pipe lining its interior (some Jiron Bolognesi 165, Puno, Peru. 188 operated by a single person where the lift was 2.4 meters, a 20 liter bucket was Swedpump Sweden filled in 6.5 seconds (i.e. at a rate of 180 l _ Ipm). At the same site, when it was ope- This is a Swedish-designed lever-arm rated by two men, 650 liters were pumped pump from Scandinavian Clinics in Stock- in 5 minutes (i.e. 130 1pm). Due to holm. It has a galvanized iron pumpstand exhaustion of the operators, these and uses a spherical plain bearing on the pumping rates could not be sustained for pumprod assembly, with ball bearings longer periods, but, nonetheless, they either side of the handle fulcrum. Below indicate that the discharge rate of this ground it uses a stainless steel lined pump is very high. Pending further acetal cylinder with a plastic piston incor- evaluation, this pump seems to meet the porating two Delrin piston rings. Delrin criteria for village-level operation and pumprod guides are used on stainless maintenance (VLOM), including being steel pumprods operating in stainless suitable for local manufacture, and being simple to maintain. All components are easily accessible. However, it is still too . soon to reach a conclusion concerning its durability when used intensively either for irrigation or community water supply. In l late 1986, the ex-factory price was approximately US$125. The pump is designed for use in wide- diameter wells. However, it is reported that an experimental version has been developed in Nicaragua which may be suitable for use in 150mm diameter tubewells. The Rope Handpump (known locally as the Bomba Manual de Soga) is manu- l factured by several small workshops in Puno, Peru, with supervision and quality India Mark II. The Sholapur pump was strengthened and the solid bar handle for control inspections provided under a joint counterweighting was added. Various I Peru-GTZ (Federal Republic of GermanY) other design changes made it possible to project. . mass produce the pump in simply Additional information: Centro de Asesoria eq ppedwro to ma it sierlt Para Bombeo de Agua, Jiron Blgei eupe okhp,t aei airt 16aPugnombPeru. Agua,JironBolognesi maintain, and to prevent tampering. At present, there are 36 manufacturers certified to make the India Mark II. Sholapur India Both the India Mark II and the Shola- pur pumps have continued to evolve. Changes to the standard specifications In the mid 1960's, the first predecessor of for the India Mark II are only made when the India Mark II was made as part of the their advantage outweighs difficulties of Jalna Project in Maharashtra State, India. changing a standard design used by The pump featured all steel construction, many different manufacturers and by inc- steel rising main. Samples of this pump a single pivot handle instead of the multi- reasing the number of spare parts that are on field trial in the Central African pivot handle typical of earlier pumps, and must be distributed. Thus some design Republic, the Sudan and Ghana. The a chain and quadrant. Although modifed, features of the Sholapur pump may be pump will be tested in the CATR labor- these basic design components remain more advanced than the India Mark II. atories during 1987. todayon the India Mark II. At present, the main differences Manufacturer: Swedpump, Scandinavian In the early 1970's, the Sholapur between the two are that the Sholapur Clinics, Box 511, S-101 26 Stockholm, Well Service improved on the Jalna pump has: (1) internal handle stops with Sweden. design, and accurately manufactured rubber cushions that reduce the chance their pump on jigs and fixtures for unifor- of finger injuries and reduce shock loads mity. Other Maharashtra-based mission on the pumphead and bearings; (2) an UPM France projects copied the Sholapur design. enlarged access cover to make it easier However, without standardized drawings, to work on the pumphead; and (3) cups The UPM is a deep-well pump manufac- dimensions tended to vary and parts were around all pumphead nuts that make it tured in France, with a number of inno- not interchangeable. Manufacture was difficult to remove them without the proper vative features. It is a reciprocating pump primarily done by mission projects manu- socket, and so reduce vandalism. How- with a lever-type handle, and is not yet facturing sufficient pumps for wells drilled ever, the Sholapur pump does not benefit mass-produced. It incorporates two impor- by their own drilling rigs. from the same quality control inspections tant departures from the mainstream of In the mid 1970's, both UNICEF and to which certified manufacturers of the conventional reciprocating handpump the Government of India became conv- India Mark II must subject their pumps. design. The pumpstand is designed to inced of the need for a standardized Manufacturer: Sholapur Well Service, act as lifting tackle for installation and pump. The Sholapur handpump was taken 560/59 South Sadar Bazar, Civil Lines, maintenance of the below ground assem- as a starting point for development of the Sholapur 413 003, India bly. The letters UPM in the original French 189 stand for "Universal Multi-Pistons", which periodically inspected a single UPM pump c _ relates to the design feature of having a in Burkina Faso, which was installed in piston, with discharge valve, located October 1983. The depth to the water every 3 meters along the pumprod. These table at this installation is only 1 Om. This pistons move within the 2-inch uPVC rising pump has performed well under conditions main. The multiplicity of pistons minimizes of heavy use, but it would be inappropriate leakage of water around them, especially to present conclusions on the repair frequ- when operated at a high velocity, and ency as data are from only a single pump, thus allows the design to do without piston installed in low-lift conditions, although it seals, leaving a clearance of 1mm over is designed to serve both low and high-lift the diameter. Piston guides are provided conditions. to centralize the motion of the pistons, In response to feedback from the lab- and thus the manufacturer claims that oratory and the field, the manufacturer friction and wear between the pistons and has made some design modifications the rising main (which doubles as an since this pump was installed in Burkina extended cylinder) is minimized. Faso. Nonetheless, it can be concluded The superstructure is made of struc- that this pump is worthy of further evalu- tural steel, and includes a 3.5m high mast ation because of its high discharge rate, with a pully at the top, and a beam with a T- corrosion resistance (when used with stainless steel rods), suitablility for a wide range of lifts, easy access to most below-ground components for inspection or repair, and its VLOM (Village Level Operation and Maintenance) approach. Manufacturer: Domine SA, 86530 Naintre, France. Wavin The Netherlands This is a direct action low-lift handpump which is not yet being mass-produced. It fl n =has been developed by a major inter- national plastics manufacturer with the participation of its operations in both India and the Netherlands. Prototypes of the pumps are being installed for field testing. Conceptually, this pump has simi- less, based on CATR laboratory tests and larities with the Tara pump made in Bangla- 1986 installation of a small number of l t desh and the Nira AF85 made in Finland Wavin pumps in Kenya, Tanzania, Malawi, . r w (for related information see the Handpump and Bolivia, the Project has observed Compendium entries for Pumps 33 and 32) that: it is easy to install, operate and in so far as all are innovative direct action maintain; it is accepted by users, espe- low-lift handpumps which have a predo- cially because of good volume flow and minant use of plastics for their below- ease of operation; discharge rates are ground components. about 25 liters per minute with typical The design concept of these direct users and heads of 7.5 to 13 meters; the action pumps holds promise for appli- piston seals require a few hours of use cations where the lift is less than about 12 before they are "bedded-in" and operating tol5 meters, and perhaps for even greater efficiently; some components, such as bar which serves as the handle. This T- lifts (the Wavin is rated by its manufac- the rods, have shown an undesirable bar handle is1 .25m wide and is.convenient turer for a lift of 25 meters, but its suit- degree of wear (the manufacturer is consi- for operation by one to four persons. A ability for such a lift has yet to be proven). dering design modifications to minimize cable passes over the mast. One end of Such pumps are light simple and easy to these problems). the cable is connected to the top of the install, are corrosion resistant due to their The Project encourages the further pumprod, and the other end to the beam- use of plastic, can be fitted into narrow development and testing of this pump by handle. This beam is fitted with an adjus- wells (the outside diameter of the Wavin is the manufacturer, and the Project itself table counter-weight. The mechanical only 50 mm), and, when mass-produced, will monitor a small number in the field. advantage of the beam-handle may be they may prove to be less expensive than Manufacturer: Wavin Overseas bv, Rolle- adjusted to suit the water depth and the many othertypes of low-lift pumps. paal 19, 7701 BR, P.O. Box 158, 7700 AD power available (one to four persons) by The design details of this pump, at Dedemsvaart, The Netherlands.. simply moving the cable connection to the least until recently, have been undergoing appropriate hook on the beam. changes as the manufacturer responds to For use where groundwater is initial feedback from laboratory and field Wearmaster U.K. aggressive, the manufacturer can supply tests. It is still premature to comment on stainless steel rods and couplings, at an repair frequency due to the short time this This hydraulic pump has been designed additional cost. The standard pumprod is pump has been available and the design to be operated by either a conventional made of galvanized steel. The Project has modifications it has undergone. Nonethe- lever-arm pumphead, a see-saw drive or 190 4Handle *: A Flexible riser pipe -Flexible hydraulic pipe bicycle drive.The pumphead contains a hydraulic unit connected by flexible pipes to another diaphragm pumping unit below ground claimed to be capable of producing over 8 liters per minute from 80 metres. This pump is expected to be tested at CATR laboratories during 1987. Manufacturer: Merrill Pumps and Engi- neering Co. Ltd, Chapel Works, Sheffield Road, Sheepbridge, Chesterfield, S41 9EH, England. 191 Complete List of Pumps Tested Number Pump ref. no. Pumpname Country of manufacture tested in Compendium Abi-ASM Cote d'lvoire, France 9 1 Abi-MN Cote d'lvoire, France 20 Annex 1 Afridev Kenya 37 2 Afridev Malawi 3 2 AID Deriv. Deepwell (Funymaq) Honduras 1 3 AID Deriv. Deepwell (Sumber Banyu) Indonesia 1 3 AID Suction Sri Lanka 13 34 Bandung Indonesia 1 35 Bestobell Zambia 1 4 Blair Zimbabwe 31 27 Blair Derivative Philippines 5 27 Blair Derivative Papua New Guinea 45 27 Blair Derivative (Madzi) Malawi 10 27 Bolivia (Ingavi) Bolivia 2 Monitoring in progress Bourga Niger, Cote d'lvoire 11 Annex 1 CIFEMA (Deriv. SIHILASE) Bolivia 6 Monitoring in progress Climax United Kingdom 1 5 Consallen LD6 United Kingdom 17 24 DMR (Dempster Derivative) Thailand 35 25 Direct Action Prototype Kenya 5 Prototypes only Direct Action Prototype Tanzania 19 Prototypes only Dragon 2 Japan 1 6 Duba Tropic 7 Belgium 32 7 Ethiopia BP-50 Ethiopia 1 28 GSW Canada 1 8 IDRC-UM Malaysia 1 29 Inalsa Suction India 5 36 India Mark II (standard) India 505 9 India Mark I1 (modified) India 11 10 Inti (Tara Derivative) Bolivia 10 Similar to Tara (No. 33) Jetmatic Deepwell Philippines 1 11 Jetmatic Suction Philippines 43 37 Kangaroo The Netherlands 11 30 Kardia Germany, Fed. Rep. 14 12 Kenya Atlas-Copco Kenya 1 Old model, discontinued 193 Number Pump ref. no. Pump Country of manufacture tested in Compendium Korat608A-1 (conventional) Thailand 51 13 Korat 608 C (modified) Thailand 40 13 Korat 608 CT (prototype) Thailand 4 13 Lucky Thailand 20 38 Maldev Malawi 198 14 Maldev Kenya 14 14 Mark V (Lutheran modified) Zimbabwe 2 31 Malawi Mark V Malawi 61 31 Monarch P3 Canada 66 15 Monitor United States 8 Monitoring in progress Mono Direct Drive South Africa 1 16 Monolift United Kingdom 30 16 Moyno Canada 190 17 Nepta (Briau) France 1 Old model, discontinued New No.6 Bangladesh 1 39 Nira AF76 Finland 93 26 Nira AF84 Finland 1 18 Nira AF85 Finland 31 32 Onga (Intersigma) Czechoslovakia 2 Unsuccessful in field trial PhilippinesDeepset, Eureka cylinder Philippines 63 19 Philippines D'set, Takasago cylinder Philippines 65 19 PVC Deep Thailand 1 Unsuccessful prototype PVC Shallow Thailand 20 Unsuccessful prototype Pb Mark II Germany Fed. Rep. 1 See India Mark II (No.9) Pek Canada 35 Annex 1 Petro Sweden 21 Production discontinued Puno Peru 15 Annex 1 Rope ("Soga") Peru 8 Annex 1 Rotary China 10 Unsuccessful prototype Rower Irrigation Bangladesh 15 40. Testing to begin soon Rower (ATA) Thailand 14 Limited observations SLB-80 China 14 Unsuccessful prototype SM-2 China 15 Unsuccessful prototype SWN 80&81 The Netherlands 39 20 SY-81 China 15 Unsuccessful prototype SYB-100 China 95 41 SYB-80 China 20 Unsuccessful prototype Sarvodaya L-4 Sri Lanka 8 Unsuccessful Sholapur India 5 Annex 1 Sihilasa (Kandy) Sri Lanka 11 Unsuccessful Six types of irrigation pumps China 18 Laboratory tested Tara Bangladesh 230 33 Treadle Irrigation Bangladesh 3 Limited field observation Turni Germany Fed. Rep. 13 Production suspended VEW A18 Austria 1 22 Vergnet France 69 21 Volanta The Netherlands 24 23 Volanta Burkina Faso/Netherlands 60 23 Wara Bolivia 5 Monitoring in progress Wasp India 25 42 Wavin (prototype) The Netherlands 16 Annex 1 Number of pump types 87 Total number of pumps 2678 194 Annex .Sn Comparison of Costs and Time Savings for CWS Options This Annex outlines a method for estimating and Table A-1. Parameters for comparing the costs and time savings of CWS options in Prototype Village specific situations. The method has been developed into a computerized calculation to aid in program design and Demoaraphiccharacteristics decision making. When choosing an option, other impor- tant factors must also be taken into account, as discus- Total population 400 sed in Chapter 2, particularly financial, resource and Persons per household 8 organizational constraints. But, if used with caution, the Total households 50 method can be a useful aid in decision making, at least Density -personsperhectare 200 to show some of the implications of deciding between alternatives. Economic conditions The inputs to the calculation, i.e. the cost and benefit parameters, vary considerably from one situation Av. value of time (US$/hr) 0.125 to another. Cost data were collected by the Project from Income (US$/capita/yr) 200 a number of countries in Africa and Asia, and these are Discount rate (%) 10 summarized under "low" and "high" cases in Table 2.2 of Electric powercost (US$/kW) 0.10 Chapter 2 (page 23). In what follows, illustrative Villaae water use and collection HP -S YT comparisons are presented, using what may be typical input parameters in a relatively efficient CWS project in a Distanceto alternative hypothetical situation. The computer program will be watersource (meters) 500 500 500 made available shortly to interested readers, who are Amount of water carried urged to explore for themselves to what extent the pertrip (liters) 20 20 - calculation can assist in their own particular circum- Walking rate (km/hr) 4 4 - stances. Collection time (min/trip) In the analysis, cost of water provided by the diffe- Travel time 1.5 1.5 - rent water supply systems is compared at the point of Fill time 1.3 1.3 - use (the home), by adding the costs of piping in the case Dailywater use (lit/cap) 20 30 60 of yardtap supplies, the value of time spent hauling water for handpumps, and a combination of the two for Watersupplysvstem standpipes. Other costs include pumps, wells, storage tanks, piping, and operation and maintenance. Number of wells 2 1 1 Because of the difficulties of identifying and Numberofwaterpoints 2 3 50 quantifying health benefits which are likely to accrue Capital cost per well (US$) 2000 2000 2740 Pumping lift (meters) 20 20 20 from an Improved water supply alone, the model uses Storagevol/dailyflow - 0.30 0.30 only time saved as the measure of benefit. The benefit- Useful life (yrs) cost analysis may therefore be useful in justifying Mechanicalequipment 10 10 10 projects only in cases where previously water had to be Non-mechanical equipment 20 20 20 drawn from outside the community. When time savings Water delivery rate (lit/min) 15 15 10 are small, health implications will be important and Annual O&M (%of cost) should be brought into the analysis separately. Mechanical equipment 10 10 10 In the model, reductions in the time taken to collect Non-mechanical equipment 1 1 1 195 water represent benefits, reducing the "price" of the optimization is needed for that option. Once the best water, and a further benefit comes from the increased configuration for each type of system has been consumption induced by a reduced collection time. determined, handpump, standpipe and yardtap systems These two elements are shown graphically on the can be compared on the basis on net benefits. stylized demand curve in Figure A-1. If a water supply The importance of the value of time is brought out improvement reduces the collection time, the "price" of when the model is applied to the prototype community, water falls from P1 to P2, with a corresponding increase with diesel as the energy source for motorized pumps. The costs and benefits for the different technologies are Figure A-1 Typical Demand Curve as shown in Table A-2. Table A-2 Costs and Benefits of Technology Options for the Prototype Village (US$/capita/year) Pi Value of time= 12.50/hr 250/hr HP SP YT HP SP YT O S20 Cost 2.1 5.5 11.7 3.2 6.5 11.7 P2 Benefit 8.0 9.1 12.2 18.1 19.8 24.5 Net Benefit 5.9 3.6 0.5 14.9 13.3 12.8 Note: Costs in dollars per capita for handpumps (HP), stand- Ql Q2 pipes (SP) and yardtaps (YT) have been calculated by adding Water use (liters per capita per day) recurrent costs to the annualized capital costs over the life of the capital equipment, at a 10% discount rate. Well cost is in per capita consumption from 01 to 02. The consumer US$2000perwell. benefits in two ways: first, the price P1 of the original Q1 Handpumps have the lowest cost and show the liters falls to P2 (shaded area Si represents the benefit) Ha n efit he the lue ost is the and second, the value placed on the extra water greatest net benefit when the value of time is 12.5¢/h., exceeds the price (benefit = shaded area S2). and that situation is unchanged, when the value of time In comparing different community water supply rises to 25¢/h, though standpipes and yardtaps are options, the model computes the total benefits S1 + S2, becoming more compettive as the value of time on te bsis f te asume loal vlueof tme,and increases. In fact, at time values over about 350/h, on the basis of the assumed local value of time, and yardtaps give the greatest net benefit. Note that at subtracts the total annualized costs of constructing, 12.5y/h, the greatest net benefit from handpumps operating and maintaining the improvements, to calcu- com es from handpumps late a net enefit for ach option.comes from two handpumps in the village of 400 people, late a net benefit for each option. while at 25o/h, the optimum number of handpumps is First, the optimum handpump and standpipe sys- three age. tems are determined by computing costs and benefits three perovillage. for povidng dfferet nubersof hadpums orTo obtain an overview of the way that community for providing different numbers of handpumps or water supply choices can be expected to turn out on a maximum net benefit. Figure A-2 illustrates the global basis, the model has been applied to a wide range optimization process for handpumps. Only one yardtap of different situations and general conclusions have optimicezlevetio proessible foner handpumpsOyouseh rdtp sbeen drawn about the sensitivity of the results to each of service level is possible (one tap per household), so no the important variables. By varying each of the para- Figure A-2 Determination of the Optimum meters in turn, their influence on the choice of tech- Fiumbre Ao2 Deterumintop fthspiu nology and service level can be evaluated. Number of Handpumps The importance of the distance to the original 20 source is brought out in Figure A-3, which indicates that I Cost technology selection is independent of the distance to <,, 15 \ the traditional source and that the distance to the tradi- tional source would have to be more than 150 meters to c,, lo ~7;~~~__ Benefit justify a handpump-based system on the basis of time X 5 _ ~ ~ _ savings alone. Note that the average distance to the new source is about 50 meters when two point sources i o are placed in the prototype village. - I The model can also be used to calculate the value of Q -5 ( | Net benlefit time at which the net benefits of two alternative -lo___I I I_ I_ technologies are equal to each other. The graphs in 0 100 200 300 400 500 Figure A-4 illustrate typical results for a range of Persons per outlet pumping lifts, well costs and village populations. The 196 Figure A-3 Influence of Distance to yes/no rural water supply decisions, but as an aid to Traditional Source on Net Benefits technology selection. Furthermore, the model is no substitute for site-specific investigations and the i 15 preference of individual communities. In situations where the model calculates a negative net benefit (short 10 Handpu distance to traditional source, low value of time, or high well costs), planners will need to make a careful assessment of other benefits than time savings, before 5 going ahead with investment. -o Yardtaps 0 Figure A-4 Examples of Technology ,s, _5 XSt Sadpipes Selection for Varying Village Parameters Z Effect of Pumping Lift 100 200 300 400 500 600 700 800 900 1,000 060 Distance to traditional source (meters) O Population = 400 persons Housing density = 25 households per hectare 0.40 Yardtaps Value of rime = $0. 125 per hour -- .E 0.20 _ Handpumps Standpipes labeled areas represent the combination of conditions where that particular technology has the highest net 0.00 benefit. The shaded area at the bottom indicates a 10 20 30 40 50 60 negative net benefit. It is in this area that consideration Pumping lift (meters) of other benefits (e.g. health impact) would be Effect of Wen Cost z0.60 necessary to justify investment in rural water supply o improvements. The general conclusions emerging from applications r 0.40 - Yardtaps of the computer model to a variety of different scenarios -O 0 are summarized in Table A-3. E Standpipes 0.20 -HandpupsSadis o ~~~Negative net benefit Table A-3 Technology Selection* 0.00 2,000 4,000 6,000 8,000 10,000 Well cost (dollars per well) Electric Diesel Effect of Population pumps pumps 0.80 Pumping lift up to 25m Well cost 45 meters SP No good Ei alternative _ at i20v Handpumps Standpipes Value of time less than 200/hr. 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