This document provides a cover page and description for a manual on designing hydraulic ram pump systems for water supply. The manual was authored by Peace Corps Volunteer Page Weil and provides comprehensive guidance for selecting sites, surveying needs, and designing ram pump installations. It includes an introduction, sections on site selection, system design, pump installation, operation and maintenance, examples, and fabrication instructions. The goal is to assist engineers in identifying and constructing ram pump systems for potable water or irrigation in rural areas without electricity.
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Hydraulic Ram Pump System Design Manual
1. COVER PAGE
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Title: Hydraulic Ram Pump System Design Manual
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Brief Description of Content:
The Hydraulic Ram Pump is a mechanical device that can pump water above the water source
WITHOUT THE NEED FOR ELECTRICITY. This pump has many applications, especially in the rural,
upland areas of the Philippines where water is difficult to access due to the need for electric pumping and the
distance and expense of an electrical power source. This manual is intended to provide a comprehensive guide
for site selection and Hydraulic Ram Pump system design.
2. Hydraulic Ram Pump System
Design Manual
Page Weil, EIT
US Peace Corps, Philippines (2006-2009)
3. INTRODUCTION .................................................................................................................................................................................. 1
1. THE BASICS................................................................................................................................................................................. 2
1.1. WHAT IS A HYDRAULIC RAM PUMP?...................................................................................................................................... 2
1.2. BASIC TERMS........................................................................................................................................................................ 2
1.3. HOW DOES A RAM PUMP WORK? ........................................................................................................................................ 4
1.4. SYSTEM DESIGN PROCESS..................................................................................................................................................... 7
2. SITE SELECTION.......................................................................................................................................................................... 8
2.1. APPROPRIATE COMMUNITY SELECTION .................................................................................................................................. 8
2.2. SYSTEM ELEMENTS AND PROPER PLACEMENT .......................................................................................................................... 8
2.2.1. River Intake Examples......................................................................................................................................... 8
2.2.2. Spring intake tank placement........................................................................................................................ 10
3. DESIGNING A HYDRAULIC RAM PUMP SYSTEM............................................................................................................... 11
3.1. TOTAL WATER USAGE........................................................................................................................................................... 11
3.2. SITE SURVEYING.................................................................................................................................................................. 11
3.3. DRIVE PIPE ......................................................................................................................................................................... 11
3.4. LOCATE STANDPIPE OR DRIVE TANK ..................................................................................................................................... 11
4. SYSTEM EXAMPLE ................................................................................................................................................................... 14
4.1. SITE VISIT AND SOURCE SELECTION ...................................................................................................................................... 14
4.2. SELECTION OF RAM PUMP SITE............................................................................................................................................ 14
4.3. CALCULATION OF REQUIRED FLOW AND STORAGE TANK SIZING ........................................................................................... 14
4.4. CALCULATION OF AVAILABLE WATER................................................................................................................................... 15
4.5. FIRST ITERATION OF DESIGN TO IMPROVE FEASIBILITY ........................................................................................................... 16
4.6. CHECK DRIVE PIPE LENGTH IF STANDPIPE IS NEEDED ............................................................................................................. 16
5. PUMP INSTALLATION.............................................................................................................................................................. 18
5.1. PUMP FABRICATION............................................................................................................................................................ 18
5.2. PUMP MOUNTING AND ALIGNMENT..................................................................................................................................... 18
5.3. PUMP AND VALVE ASSEMBLY ............................................................................................................................................. 19
5.3.1. Impulse Valve ..................................................................................................................................................... 19
5.3.2. Delivery Valve Assembly ................................................................................................................................. 21
5.4. STARTING THE PUMP ............................................................................................................................................................ 21
6. OPERATIONS AND MAINTENANCE..................................................................................................................................... 22
6.1. GROUP TO MAINTAIN SYSTEM ............................................................................................................................................. 22
6.2. COMMON RAM PUMP MAINTENANCE PROBLEMS .............................................................................................................. 22
6.3. OPERATIONS AND MAINTENANCE WEEKLY CHECKS ........................................................................................................... 22
7. BIBLIOGRAPHY........................................................................................................................................................................ 24
8. APPENDIX................................................................................................................................................................................. 25
8.1. EXAMPLES OF RAM PUMP INSTALLATIONS ........................................................................................................................... 25
8.2. RAM PUMP EXAMPLE SYSTEM DETAILS ................................................................................................................................ 27
8.3. S-2 RAM PUMP DESIGN CHANGES .................................................................................................................................... 36
8.4. S-2 RAM PUMP FABRICATION INSTRUCTIONS...................................................................................................................... 39
4. TABLE LISTING
TABLE 1 – BASIC SYSTEM DATA.............................................................................................................................................................. 14
TABLE 2 - DRIVE PIPE SIZING CHART ...................................................................................................................................................... 17
TABLE OF FIGURES
FIGURE 1 - RAM PUMP SYSTEM TERMS ..................................................................................................................................................... 2
FIGURE 2 - S-2 RAM PUMP...................................................................................................................................................................... 3
FIGURE 3 - STEP 1 OF RAM PUMP CYCLE ................................................................................................................................................ 4
FIGURE 4 - STEP 2 OF RAM PUMP CYCLE ................................................................................................................................................ 5
FIGURE 5 - STEP 3 OF RAM PUMP CYCLE ................................................................................................................................................ 6
FIGURE 6 - STEP 4 OF RAM PUMP CYCLE ................................................................................................................................................ 6
FIGURE 7 - STEP 5 OF RAM PUMP CYCLE ................................................................................................................................................ 7
FIGURE 8 – RIVER INTAKE AND SETTLING TANK ......................................................................................................................................... 9
FIGURE 9 - SECTION THROUGH SETTLING TANK ........................................................................................................................................ 9
FIGURE 10 - (3) RAM PUMPS INSTALLED IN PARALLEL WITH A STREAM INTAKE .......................................................................................... 9
FIGURE 11 - (2) RAM PUMPS INSTALLED IN SERIES.................................................................................................................................. 10
FIGURE 12 - EXAMPLE SPRING INTAKE STRUCTURE.................................................................................................................................. 10
FIGURE 13 - STANDPIPE/DRIVE TANK PLACEMENT ................................................................................................................................. 13
FIGURE 14 - EXAMPLE OF STEEL RAM PUMP CRADLE USING 40MM STEEL ANGLE BARS ........................................................................ 19
FIGURE 15 - “NORMAL” RAM PUMP INSTALLATION............................................................................................................................... 25
FIGURE 16 - RAM PUMP SYSTEM WITH DRIVE TANK (OR STANDPIPE)...................................................................................................... 25
FIGURE 17 - RAM PUMP SYSTEM WITH STANDPIPE .................................................................................................................................. 26
5. Introduction
As the world’s population continues its precipitous rise, the world’s resources are subject to
ever increasing competition and price increases. Nations across the world are searching
for alternative technologies that can move them towards energy independence. When
the cost of electricity rises, so does the cost of pumped water. Hydraulic Ram Pumps are
one of the oldest appropriate technologies pertaining to water, they require no electricity
to operate, and are relatively low-maintenance. Developed in France in 1796 by the
Mongolfier Brothers, the concept of the hydraulic Ram Pump has been applied worldwide
in dozens of different configurations.
This manual is intended to assist experienced design engineers attempting to identify and
construct a Hydraulic Ram Pump system for potable water or irrigation use. The specific
device in question is an S-2 Ram Pump designed and tested by the Development
Technologies Unit at the University of Warwick in the mid 1990’s. Inside are overviews of site
selection, system design, pump fabrication and cost estimation. With confidence, the
reader should have no problem designing, constructing and maintaining a rural water
supply system. If this manual is found by a non-technical worker, they should seek the
assistance of a design engineer in explaining and implementing the ideas within.
The information contained within this manual should be credited to the various
development and extension departments at Clemson University in the USA, and the
University of Warwick in the UK; his manual is merely a compilation and clarification of their
work. In the Philippines, the Ram Pump design research developed by these universities
was tested in a rural setting. The following agencies must also be thanked for their funding
and support:
US Peace Corps
The Peace and Equity Foundation of the Philippines
Aquinas University of Legaspi, Albay
Alternative Systems for Community Development Foundation (ASCODE), inc.
The Municipal Government of Jovellar, Albay, Philippines
The Philippine Department of Social Welfare and Development:
Kalahi: CIDSS Program
1
6. 1. The basics
1.1. What is a hydraulic Ram Pump?
A Hydraulic Ram Pump is a non-electric pump that uses the energy of a large amount of
water falling to raise a small amount of water to a high elevation. Although originally
designed for use in village water supply, Ram Pumps have been used successfully in
agriculture as well. The Ram Pump is especially applicable for upland areas where water
sources are strong but access is limited due to their distance from the users.
Ram Pumps have been used in both developed and developing countries worldwide for
hundreds of years. The Ram Pump was invented in France in the 1700s and has seen
widespread acceptance due to its relatively low operation cost and non-electric nature.
Dozens of Ram Pumps have been installed in the Philippines in Bohol, Palawan and, as of
2008, Bikol.
Included in this manual are fabrication instructions for the S-2 Ram Pump, designed by the
Development Technologies Unit of the University Of Warwick, England. The pump can be
made at any machine shop with access to a lathe, drill press and welding machine.
1.2. Basic Terms
Figure 1 - Ram Pump System Terms
2
8. 1.3. How does a Ram Pump Work?
The concept behind the ram idea is a “water hammer” shock wave. Water has weight, so
a volume of water moving through a pipe has momentum. If a car runs into a brick wall
the result is crumpled metal. If a moving water flow in a pipe encounters a suddenly
closed valve, a pressure “spike” or increase suddenly appears due to all the water being
stopped abruptly (that’s what water hammer is - the pressure spike).
Although this is a different model from the Ram Pump discussed in this manual, here’s how
the Ram Pump actually works, step-by-step:
Figure 3 - Step 1 of Ram Pump Cycle
In Figure 3, Water (blue arrows) starts flowing through the drive pipe and out of the “waste”
valve (#4 on the diagram), which is open initially. Water flows faster and faster through the
pipe and out of the valve
4
9. Figure 4 - Step 2 of Ram Pump Cycle
Figure 4 - At some point, water is moving so quickly through the brass swing check “waste”
valve (#4) that it grabs the swing check’s flapper, pulling it up and slamming it shut. The
water in the pipe is moving quickly and doesn’t want to stop. All that water weight and
momentum is stopped, though, by the valve slamming shut. That makes a high pressure
spike (red arrows) at the closed valve. The high pressure spike forces some water (blue
arrows) through the spring check valve (#5 on the diagram) and into the pressure
chamber. This increases the pressure in that chamber slightly. The pressure “spike” the pipe
has nowhere else to go, so it begins moving away from the waste valve and back up the
pipe (red arrows). It actually generates a very small velocity backward in the pipe.
5
10. Figure 5 - Step 3 of Ram Pump Cycle
Figure 5 - As the pressure wave or spike (red arrows) moves back up the pipe, it creates a
lower pressure situation (green arrows) at the waste valve. The spring-loaded check valve
(#5) closes as the pressure drops, retaining the pressure in the pressure chamber.
Figure 6 - Step 4 of Ram Pump Cycle
Figure 6 - At some point this pressure (green arrows) becomes low enough that the flapper
in the waste valve (#4) falls back down, opening the waste valve again.
6
11. Figure 7 - Step 5 of Ram Pump Cycle
Figure 7 - Most of the water hammer high pressure shock wave (red arrows) will release at
the drive pipe inlet, which is open to the source water body. Some small portion may travel
back down the drive pipe, but in any case after the shock wave has released, pressure
begins to build again at the waste valve (#4) simply due to the elevation of the source
water above the ram, and water begins to flow toward the hydraulic ram again.
Water begins to flow out of the waste valve (#4), and the process starts over once again.
The ram pump will usually go through this cycle about once a second, perhaps somewhat
more quickly or more slowly depending on the installation.
1.4.System Design Process
For a Ram Pump system to function well, it must be designed with careful consideration
of the surrounding area and water requirements of the users. This is the design process
we will follow in this manual:
1) Community identification, site selection and source flow measurement
2) Calculation of water requirements of community
3) Topographic surveying of site
4) Determining pump configuration
5) Calculation of available supply by Ram Pump
6) Pipe and tank sizing
7) System detailing (tanks, pipes, access points)
7
12. 2. Site selection
2.1. Appropriate community selection
As with any kind of infrastructure development, the community must be consulted first to
determine project feasibility. Residents of poor, rural barangays have a good idea of their
water problems, local water sources, water quality and seasonal variations in source flow.
Ram Pumps function by utilizing the energy of a large volume of falling water to pump a
smaller volume of water far above the water source. In any site investigation for a Ram
Pump installation, one should always be looking for water sources on steeply sloping
ground. The S-2 Ram Pump is designed to function with drive heights of 2 to 15 meters and
delivery heights of up to 100 meters. This Ram Pump design can use between 40 and 120
liters/min minute of water; any less than 40 liters/min and the pump may not function.
Ram Pumps can be powered by either flowing surface water (rivers and streams) or spring
water. Spring sources usually have lower source flow, but the water will usually not need
treatment to make it potable. Rivers and streams have high flow rates but usually have
suspended sediments that will need to be settled out before the water can enter the Ram
Pump. Water from rivers and streams is not potable, so a filtration or chlorination device will
need to be installed to ensure the health of the users. Streams have the added danger of
flooding and the risk of damage to the system. In general, river or stream intakes are best
used for agricultural applications of Ram Pumps while spring sources are best for village
water supply.
Once a site has been identified, a topographic survey must be conducted to calculate the
exact elevation differences and distances between the intake box, the drive tank, the Ram
Pump and the storage tank. On that site visit, the source flow rate should be determined
as well.
2.2. System elements and proper placement
The system intake can be from any kind of surface or ground water, so long as the
topography will allow for the vertical fall from the intake to the Ram Pump. The source flow
should be captured in a retention tank to maintain a constant depth of water above the
drive pipe intake. Also, a retention tank allows for the removal of trash and sediment from
the system (Figure 8). More system installation examples can be found in Appendix 8.1.
2.2.1. River Intake Examples
8
13. Figure 8 – River Intake and Settling Tank
Figure 9 - Section Through Settling Tank
Depending on the available flow rate from the water source and the local topography,
Ram Pump installations can be configured in many different ways:
Figure 10 - (3) Ram Pumps Installed in Parallel with a Stream Intake
9
14. Figure 11 - (2) Ram Pumps Installed in Series
2.2.2. Spring intake tank placement
Springs can be a good choice for a Ram Pump water source due to their potability and
lack of silt.
Water that will be pumped must be captured in a sealed spring intake box first and then
piped into the system. Spring sources are usually free of sediment and, if protected
properly from runoff, can maintain good water quality with minimal maintenance.
Figure 12 - Example Spring Intake Structure
10
15. 3. Designing A Hydraulic Ram Pump System
3.1. Total water usage
Before any Ram Pump system can be designed, there are certain pieces of information
that must be gathered:
1. The difference in elevation between the water source and the proposed Ram Pump
site.
2. The difference in elevation between the Ram Pump and proposed storage tank.
3. The available flow rate of water from the source.
4. The required flow rate at the storage facility
5. The distance from the source to the Ram Pump site
6. The distance from the Ram Pump site to the storage facility.
Calculation of available water is in section 4.4
Note: This data gathered may be changed to increase Ram Pump output or decrease
piping costs. Engineering design is an iterative process and these numbers can change to
decrease the cost of the system.
3.2. Site Surveying
Since the initial guess for Ram Pump and storage tank location will not always be correct, it
is very important to
3.3. Drive Pipe
The drive pipe runs from the water source directly into the Ram Pump. When the Ram
Pump closes, the pressure wave disperses in this pipe, so it is important that this pipe be
rigid. The more rigid the drive pipe, the more efficient the pump will be (and the more
water that can be pumped to the storage facility).
The length of the drive pipe is based on the location of installation. For the pump to
function efficiently (or at all) the drive pipe must fall within certain limits. The maximum and
minimum lengths of drive pipe are based on the drive pipe length (L) and the drive pipe
diameter (D). If the distance from the intake to the Ram Pump is longer than the maximum
pipe length, a standpipe should be placed in the system.
3.4. Locate standpipe or drive tank
If the distance from the intake to the pump is longer than the maximum drive pipe length,
the system needs a standpipe. Stand pipes are only necessary if the drive pipe will be
longer than the recommended maximum length (for instance, in the previous example a
stand pipe may be required if the drive pipe were to be 150 feet in length, but the
maximum drive length was determined to be only 104 feet). The stand pipe - if needed - is
11
16. generally placed in the line the same distance from the ram as the recommended
maximum length indicated.
The stand pipe must be vertical and extend vertically at least 1 foot (0.3 meter) higher than
the elevation of the water source - no water should exit the pipe during operation (or
perhaps only a few drops during each shock wave cycle at most). The standpipe should
be at least 1” larger than the drive pipe. The supply pipe (between the water source and
the stand pipe) should be 0.5” larger than the drive pipe.
The reason behind this is simple - if the drive pipe is too long, the water hammer shock
wave will travel farther, slowing down the pumping pulses of the ram. Also, in many
instances there may actually be interference with the operation of the pump due to the
length of travel of the shock wave. The stand pipe simply allows an outlet to the
atmosphere to allow the shock wave to release or dissipate. Remember, the stand pipe is
not necessary unless the drive pipe will have to be longer than the recommended
maximum length.
Another option would be to pipe the water to an open tank (with the top of the tank at
least 1 foot (0.3 meter) higher than the vertical elevation of the water source), then attach
the drive pipe to the tank. The tank will act as a dissipation chamber for the water hammer
shock wave just as the stand pipe would. This option may not be viable if the tank
placement would require some sort of tower, but if the topography allows this may be a
more attractive option.
Figure 13 shows the proper installation of a Ram Pump with a drive tank; the feed pipe
follows the contour of the hill to get as close as possible to the Ram Pump before the drive
tank.
12
18. 4. System example
This section is a guide through the design process for a basic Ram Pump system.
Table 1 – Basic System Data
Ew Elevation of water source 500m
Es Elevation of consumers/storage 525m
Lr Distance from source to Ram
Pump
75m
Ls Distance from Ram Pump to
consumers/storage
250m
Qs Minimum water source flow rate 1 liter/second
Ps Current Population at Site 120ppl
G Population Growth Rate 2.5%
n Design life of system 10yrs
4.1. Site visit and source selection
In this example, the initial site selection and survey has been performed. Table 1 has the
basic data to design this system. Due to seasonal variations in water supply, the minimum
source flow rate is used.
4.2. Selection of Ram Pump Site
The Ram Pump must be placed from 2 to 10 meters below the elevation of the water
source. Once the Ram Pump site is selected, the drive height and delivery height can be
calculated.
Er = 496 m
Hd = Ew – Er (1)
Hd = 500m – 496m = 4m
Where: Hd = Drive Height (m)
Ew = Elevation of Water Source (m)
Er = Elevation of Ram Pump site (m)
4.3. Calculation of required flow and storage tank sizing
Pf = Ps * (1 + G)^n (2)
Pf = 120ppl * (1 + 2.5%)^(10yrs) = 154ppl
Where: Pf = Design population (ppl)
14
19. Ps = Current Population (ppl)
G = Population Growth Rate (%)
N = Design life of system (yrs)
Per capita water use varies both by location (urban vs. rural) and type of water system
(household connections vs. communal faucets). For the sake of the example, it is assumed
that a single person uses 50 liters of water per day for all domestic purposes (drinking,
cooking, bathing, laundry, etc.).
Vd = Pf * 50 l/ppd (3)
Vd = 154ppl * 50 l/ppd = 7700 liters/day
Qr = 7700 liters/day / 24 hrs/day / 60 min/hr / 60 sec/min = 0.089 lps
Where: Vd = Daily water usage (liters)
Pf = Design population (ppl)
Qr = Required flow rate at storage tank (lps)
4.4. Calculation of available water
Ram Pump efficiency has been determined by a number of research organizations to be
between 33% and 66% depending on the quality of the installation. In this example, the
Ram Pump will be 45% efficient.
The elevation difference between the water source and Ram Pump is called the “drive
height”. The elevation difference between the storage tank and the Ram Pump is called
the “delivery height.” The following equation gives an approximate flow rate at the storage
tank:
Qa = Qs * e * (Ew – Er) / (Es – Er) (4)
Qa = 1 lps * 45% * (500 – 496) / (525 – 496) = 0.062 lps
Qa = 0.062 lps * 86400 sec / day = 5362 liters/day
Where: Qa = Water Available From Ram Pump (lps)
Qs = Minimum Water Source Flow Rate (lps)
e = Pump Efficiency (%)
Ew = Elevation of Water Source (m)
Er = Elevation of Ram Pump (m)
15
20. Es = Elevation of Storage Tank/Consumers (m)
4.5. First Iteration of Design to improve feasibility
Qr = 0.089 lps (Water required based on number of users; section 4.3)
Qa = 0.062 lps (Water available from initial Ram Pump system configuration)
Since Qr > Qa, this system is currently unfeasible.
There are several ways to solve this problem:
1. If the source flowrate is large enough, add additional pumps in parallel to
increase the amount of water delivered.
2. Decrease delivery height by building the storage tank at a lower elevation
3. Increase drive height by building the Ram Pump at a lower elevation
4. Decrease the per-capita water demand by making a system with communal
faucets instead of household connections (Level III -> Level II)
In this design example the source flow rate is only at 1 lps so solution 1 is unfeasible. It is
assumed that the storage tank cannot be moved to a lower elevation because of the
location of the users, so solution 2 is unfeasible. Solution 3, increasing the drive height by
lowering the Ram Pump site will be tested:
Equation 4 is solved to calculate the needed Ram Pump Elevation (Er) for the system to be
feasible.
Qr = Qs * e * (Ew – Er) / (Es – Er)
Qr * (Es – Er) = Qs * e * (Ew – Er)
Qr * Es – Qs * e * Ew = Er * (Qr – Qs *e)
Er = (Qr * Es – Qs * e * Ew) / (Qr – Qs * e)
Er = (0.089 * 525 – 0.5 * 45% * 500) / (0.089 – 0.5 * 45%)
Er = 483 m
Ew - Er = 525 - 483 = 42m (New delivery height)
Es - Er = 500 - 483 = 17m (New drive height)
4.6. Check drive pipe length if standpipe is needed
16
21. Next, the drive pipe must be sized and the length determined. Table 2 can be used to
determine drive pipe size.
Table 2 - Drive Pipe Sizing Chart
Source Flow Rate
(lps)
Drive Pipe Diameter
(inches)
0.66 to 1 1ӯ
1 to 1.33 1.5ӯ
1.33 to 2 2ӯ
In this example, the minimum source flow rate is 1 liter/sec, so a drive pipe size of 1.5ӯ will
be used. Using the drive pipe diameter, the drive pipe length must be checked. If the
drive pipe is too long or too short, the ram shockwave will dissipate to quickly or too slowly
and the pump may not function correctly, if at all.
LdMin = 150 x Dd (5)
LdMax = 1000 x Dd (6)
LdMin = 150 x 1.5” = 225” = 5.72m
LdMax = 1000 x 1.5” = 1500” = 38.1m
Lr = 75m (From Table 1)
Lr > LdMax; the drive pipe is too long; this system will need a standpipe
Where: LdMin = Minimum Drive Pipe Length (m)
LdMax = Minimum Drive Pipe Length (m)
Lr = Distance from water source to Ram Pump (m)
Since the distance from the source to the Ram Pump is longer than the maximum
allowable length of the drive pipe, a standpipe must be placed in the system. The
standpipe should be placed as far from the Ram Pump is possible to give the Ram Pump
the maximum possible drive head.
In this case, the standpipe should be no farther than 38m from the Ram Pump. The actual
location of the standpipe should be surveyed to determine its elevation.
17
22. 5. Pump Installation
5.1. Pump Fabrication
See Appendix 0 for full details on S-2 Ram Pump fabrication.
IMPORTANT NOTE: There are two sections of the pump fabrication manual, one is the
original DTU design, the other is a page of design changes that should be considered
before fabrication. Before attempting to fabricate a Ram Pump, both sections should be
read thoroughly.
In Legaspi City, Albay, there is an experienced fabricator who has made 4 pumps without
a problem:
Ravalo Machine Shop and Auto Supply Inc.
Circumferential Road, Capantawan, Legaspi City
Tel Nos. (052) 820-5445 or (052) 480-5115
5.2. Pump mounting and alignment
Ram Pumps should be securely fastened to a concrete or steel base to prevent them from
moving. On every pump cycle, the pressure wave causes the pump to move and, If not
properly secured, the pump will break and may damage the pipes as well. Figure 14 shows
an example of a steel pump mount mounted in a concrete base. Pumps can also be
mounted on stainless steel bolts embedded in a concrete base.
Remember: Any kind of pump mount should be aligned using the pump body to make sure
the pump will fit. Without proper alignment, the pump will not fit and the base may have to
be remade.
18
23. Figure 14 - Example of Steel Ram Pump Cradle Using 40mm Steel Angle Bars
5.3. Pump and Valve Assembly
5.3.1. Impulse Valve
1. Look at the valve stem. The end with
more threads will be for the bottom.
2. Tighten a nut down to the bottom of the
long threads
3. Add a steel washer and then a rubber
washer to the rod.
4. Place the first valve disc, then the valve
rubber, then the second valve disc on the
rod
5. Add a rubber washer and then a
steel washer.
6. Add one nut to the threads and
tighten it using your hand. Once it is tight,
make one full turn with the wrench.
7. Add a second nut and lock them
together.
19
24. 8. Place the valve rod through the valve plate and the stop bar with the short threads
at the top.
9. Add washers for spacing and then 2 nuts.
10. Adjust the pump and then lock the nuts in place.
11. When the valve is closed, the nuts should be no more than 1cm above the top
washer.
12. Test the valve by moving it up and down. It should move up and down easily, and
without rubbing the sides of the stop bar.
20
25. 5.3.2. Delivery Valve Assembly
40mm M10 Bolt
Steel Washer Bolt
Rubber Washer
Valve disc (64mm
Diameter, 3mm thick)
Steel Washer
Nuts
1. Clean off the delivery plate and remove any rust.
2. Place steel washer on bolt
3. Place rubber washer on bolt
4. Place valve disc on bolt. The disc should move freely up and down and not stick
when placing it on the bolt. Make sure the smooth side is facing down! The valve may not
work properly otherwise
5. Place the bolt through the delivery plate
6. Place a small steel washer on the bolt
7. Tighten one nut until the valve can move up and down 2mm.
8. Lock a second nut against the first.
5.4. Starting the pump
The pump will have to be manually started several times when first placed in operation to
remove the air from the ram pump piping. Start the pump by opening all valves on the
intake box, drive line and Ram Pump. Water will flow from the opening of the impulse
valve until it suddenly shuts. Push the impulse valve open (it will be difficult, use your foot)
and wait for it to shut again. You may have to push the impulse valve open repeatedly to
re-start the pump in the first few minutes (10 to 20 times is not abnormal) - air in the system
will stop operation until it is purged.
21
26. 6. Operations and Maintenance
6.1. Group to maintain system
Ram Pump systems can be designed and constructed quite cheaply and easily, but
require constant maintenance. Over time, the moving parts and gaskets of the pump will
wear out and need replacement. Pump repairs are not very complex and a community-
based organization, if properly trained, can easily maintain the Ram Pumps for long periods
of time. In addition, a local water and sanitation organization can collect a small fee from
all water users to pay for replacement parts and an honorarium for the caretaker.
The system’s caretaker needs to live close enough to the system to check on the pumps at
least twice a week. In rural areas, people often live near a source of water; caretakers
who live closer to the pumps are more likely to visit and accept a sense of ownership over
the system.
6.2. Common Ram Pump Maintenance Problems
The S-2 Ram Pump has been installed and tested in many different countries. Over time, a
list of common problems was developed. These problems have been addressed in
Appendix 0.
6.3. Operations and Maintenance Weekly Checks
The pump should be checked weekly, if possible, to keep it running consistently. All
information should be recorded in a logbook so recurring problems can be identified. The
basic monthly checks are as follows:
1. Intake Box
a. Open the fittings and clean out any debris
b. Fix trenches to divert water around the tanks
2. Ram Pumps - Open each Ram Pump and inspect each valve
i. Main valve:
1. Is the valve rod being worn down?
2. Valve rubber disc still in good condition?
3. Are the bolts tight?
4. Are the bolts/nuts rusty?
ii. Delivery valve
1. Can the valve move up and down about 2mm?
2. Are the nuts locked against each other?
3. Is the rubber disc intact?
4. Is there rust?
iii. Snifter valve
1. Is the small hole still sealed?
22
27. 2. Is the bolt tight?
3. Is the hole blocked?
iv. Bolts and gaskets
1. Oil all bolts and gaskets
2. Are the bolts and nuts rusty?
3. Are the gaskets in good condition?
3. Water Storage Tank
a. Measure water level
b. Check for leaks. If there is a major leak, drain the tank and plaster the leaky
spot with cement.
c. Check that the lid is on
d. Repair trenches to divert water away from the tank (overflow, drain pipe)
4. Pipes
a. Walk pipe route and look for wet spots where the pipe may be leaking
b. Drive Pipes
c. Check pipe fittings for leaks
d. Check pipe for excess movement during pump cycle
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28. 7. Bibliography
Clemson University Cooperative Extension Service (2007). Home-made Hydraulic Ram
Pump Retrieved September 21, 2008 from http://www.clemson.edu/irrig/equip/ram.htm
Lifewater: Water for the World. Designing a Hydraulic Ram Pump; Technical Note No.
RWS.4.D.5. Retrieved September 21, 2008 from
http://www.lifewater.org/resources/rws4/rws4d5.htm
University of Warwick Development Technologies Unit (1998). DTU Technical Release No.
14: The DTU S-2 Pump. Retrieved September 21, 2008 from
http://www2.warwick.ac.uk/fac/sci/eng/research/dtu/lift/pubs/#tr
Thomas D. Jordan. A Handbook of Gravity-Flow Water Systems.
Intermediate Technology Publications. London. 1984.
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29. 8. APPENDIX
8.1. Examples of Ram Pump Installations
Figure 15 - “Normal” Ram Pump Installation
Figure 15 demonstrates the “normal” ram system where the drive pipe is less than the
maximum length allowed. No stand pipe or open tank is required.
Figure 16 - Ram Pump System with Drive Tank (or Standpipe)
Figure 16 shows one system option where the drive pipe is longer than the maximum length
allowed. The open water tank is required to allow dissipation of the water hammer shock
wave.
25
30. Figure 17 - Ram Pump System with Standpipe
Figure 17 is another option used where the drive pipe is longer than the maximum length
allowed. The stand pipe (open to atmosphere at the top) is required to allow dissipation of
the water hammer shock wave.
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31. APPENDIX
8.2. Ram Pump Example System Details
8.2.1. RP1 - Ram Pump Fitting Detail
8.2.2. RP2 - Ram Pump Enclosure Detail
8.2.3. RP3 - 9000L Reservoir Detail
8.2.4. RP4 - Communal Faucet Detail
8.2.5. Bill of Materials for Example System
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