RP-01638

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Table 1. Summary of performance data." Number Volumetric Water Avg water Pump Date of efficiency head output number Type installed users (%) (m) (Llday) PA4 lift 512181 12 60 1.93 715 PAS lift 113181 15 64 2.63 800 NE, lift 3019181 8 56 1.41 1000 NEZ lift 12110181 150 63 0.99 2100 'No observations made on down-time or on maintenance and repairs. b1 m = 3.28 feet; 1 L = 0.22 gallon. Period monitored 113181-1515182 114181-1515182 30110181-1515182 15111181-1515182 75 70 65 60 55 PAS NE2 ------ PA4 NE, 50 3 2 1 1 1 I I I I I - - - - I I I I I I I I I PA5 PA4 NE1 NE2 0 25 1 I I 1 I 1 1 2 .. NE2 10 - - - - - - - - - - - - - - - NE 1 PAS PA4 5 I I I I I I I M A M J J A S 1981 1982 j I I I I I I I O N D J F M A M MONTH Fig. 5. Volumetric efficiency, average water head, and monthly mean of the average daily delivery of the four pumps during fieldtesti ng. 36
At a standard frequency of about 40 strokes per minute, the same 20-L can was filled to capacity while counting the actual number (n,) of strokes. The volumetric efficiency was then computed from the formula: Volumetric efficiency (%) _ (nu,/n,) x 100 The water head (distance between the water level in the well and the pump spout) was measured by using a calibrated string weighted at one end with a float. Since no counter was installed to measure pump usage, the determination of total volume of water pumped was estimated. Monitors at the village recorded the number of 20-L cans (provided at the pump site for this purpose) that the village people pumped per day. This was used as the basis to estimate the amount of water pumped per month. The thickness of the upper and lower piston rings at three points was measured monthly. The percentage rate of wear was then determined from the past and present measurements. Highlights of Findings The project was able to install 30 Waterloo pumps in several areas: Jala Jala Islands in Laguna (10), Cavite (9), Pangasinan (7), and Nueva Ecija (4). Of these 30 pumps, only 4 (13%) were considered functional/operational and appropriate for monitoring purposes. The other 26 pumps were eventually abandoned as they were beset with one or more of the following seven problems: (1) high leakage rate; (2) users found the pump to be very difficult, strenuous, and inconvenient to use because it took quite a long time to prime and draw water. (This situation is described with humour by one user with the following statement: "Our sweat comes out first before we pump out water."); (3) defective foot valve; (4) caving in of the well; (5) people eventually abandoning the use of the pumps because they started to draw up brackish or muddy water; (6) piston stuck and could not be extracted; and (7) foot valve slipped out of the casing and dropped down the well. Given the alternative of being able to use other existing pumps (Jet-matic and pitcher pumps), the village users eventually switched to these other pumps. The original Waterloodesigned handpump that was fabricated according to specifications did not function as efficiently as expected when tested initially. The following specific observations were made. The foot valve did not hold water satisfactorily because: (1) the original gasket or the seal (polyethylene ring) was not effective; (2) sand particles became trapped between the plastic flapper valve and the valve seat and caused poor seating of the valve; and (3) there was excessive clearance between the valve guide and the flapper valve. The piston's performance was similar to that of the foot valve. Filter The PVC filter did not function adequately. This may have been because the screen slots were too big and allowed fine sand and silt to pass. Another reason was that some wells were not adequately developed. To try to overcome these problems, changes were made in the design of the foot valve. These changes included incorporating a brass spring, using a rubber gasket, and chamfering the valve seat to prevent sand particles from wedging between the flapper valve and the valve seat. These modifications improved the performance of the pumps slightly. However, it is not possible to state conclusively whether the improved performance was due solely to the modifications or was due to the fact that the wells had louver pumping heads: the four operational pumps had a water head of less than 10 feet (3 m). Even when the Malaysian foot-valve design was tried, technical problems with the foot valves continued to be a major constraint. One interesting finding that has always puzzled the team is the seepage rate encountered in all the wells. Although a stronger spring was installed for the flapper valve, a high seepage rate persisted. This meant that 50-70 strokes of the pump handle were required to raise the water column so that water could be obtained; however, after a short period without pumping, the level of the water in the column fell back to the level of the ground water. Thus, priming had to be repeated. For areas with a high water table, like Aliaga, Nueva Ecija, and Pangasinan, the tedious process of raising the water column was not much of a problem. For deep wells, however, this is a very serious problem. 37
Page 1 and 2: ARCHIV SHARP no. 1
Page 3 and 4: IDRC-204e Village Handpump Technolo
Page 5 and 6: Contents Preface ..................
Page 7 and 8: Preface Many factors are involved i
Page 9 and 10: Introduction The precise links betw
Page 11 and 12: The primary objectives of these stu
Page 13 and 14: Sri Lanka Pathirana Dharmadasa, lJp
Page 15 and 16: m O C O x 00 N .,y D+ O G+ CL C n Q
Page 17 and 18: 13 8 -6 7 9 10 A B C Fig. 4. (A) LI
Page 19 and 20: in the village can easily make a ne
Page 21 and 22: Table 2. Overview of performance da
Page 23 and 24: Thailand Pichai Nimityongskul and P
Page 25 and 26: L -' 0 inch 3 cm 8 A B Fig. 1. (A)
Page 27 and 28: The tensile strength of the PVC pip
Page 29 and 30: 0 4 A B OF inch 1 cm 4 10 01 1 inch
Page 31 and 32: water per 10-cm stroke, changes in
Page 33 and 34: Fig. 11. Below-ground components of
Page 35 and 36: Philippines Antonio Bravo This repo
Page 37: 2 Fig. 3. Modified version of above
Page 41 and 42: Malaysia Goh Sing Yau The populatio
Page 43 and 44: AP. AP (FU + FD) (WW1 + WW2 + BP +
Page 45 and 46: Optimum Design It is difficult to s
Page 47 and 48: 10 4 1 A B Fig. 6. (A) Piston assem
Page 49 and 50: made from a 0.5-inch (1.27-cm) thic
Page 51 and 52: PK 006S2 312181 717181 60 1019181 0
Page 53 and 54: was found only in: (1) the top wood
Page 55 and 56: Overview of Technical Performance G
Page 57 and 58: Ln Country and model Pedestal Table
Page 59 and 60: Economic Analysis and Potential Mar
Page 61 and 62: program is being curtailed by the l
Page 63 and 64: cylinder: PVC is one-third the cost
Page 65 and 66: about 50% of the cost of the existi
Page 67 and 68: Table 7. Summary of important handp
Page 69 and 70: Conclusions In an era of rapid deve
Page 71 and 72: Malaya proposes to address this que
Page 73 and 74: Participants ZAINUDDIN ARSHAD, Mini

RP-01638

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