Received: 29 January 2020 Revised: 28 September 2020 Accepted: 28 September 2020
The use of hydraulic ram pump for increasing pump
Wanchai Asvapoositkul T. Nimitpaitoon S. Rattanasuwan P. Manakitsirisuthi
King Mongkut’s University of Technology
Thonburi, Bangkok, Thailand
Wanchai Asvapoositkul, Department of
Mechanical Engineering, King Mongkut’s
University of Technology Thonburi, 126
Pracha Uthit Rd, Bang Mod, Thung Kru,
Bangkok 10140, Thailand.
The combined pump and hydraulic ram pump (HRP) was presented to evalu-
ate the technical feasibility for increasing pump head. This method was used to
demonstrate a possible low-cost alternative solution to supply water in remote
areas. It illustrated the case where energy in rivers was not enough to drive
HRP and a pump alone could not lift water to the required head. The HRP was
connected in series with the pump. The experiment on the combined system
operation was investigated. The system was working only at a certain range of
flow rates for a power supply by the pump. Therefore, HRP was adjusted to pump
water in the range that the waste valve was functioning. The combined system
can operate at a low flow rate with a high head without extra energy and no over-
loading. It reveals that the more discharge head is required, the less flow can
be lifted which results in a high number of valve beats per minute of the waste
valve. Experimental determination of the optimal values for these parameters
will make it possible to provide for a feasible design of HRP in the given pump.
The optimal HRP will make it possible to ensure the required performance
(delivery, head, efficiency) of the combined system.
application of HRP, combined pump and hydraulic ram pump, experiment, increasing pump head,
valve beats per minute of the waste valve
Ideally, a pump should deliver flow at a pressure or head efficiently and reliably over a wide range of operating conditions.
Installed water pumps in some cases are insufficient to meet head or lift fluctuations. This can occur during a drought
when water levels in rivers or canals fall, and the head or lift increases. A variety of workable solutions to the problem
exist, such as adding another pump in series, or installation of an over-design pump, but the added pump will generally
cost. This is a real and serious problem in many places, especially in the north-east of Thailand where the people live
in poverty and remote rural areas. A possible low-cost alternative solution to supply water in remote areas is required.1
Despite many different pump designs and installations, the purpose of this paper is to increase the pump head in those
remote areas of limited use of pumps. In a situation where the people could not afford to buy a new pump. This came
across when we learned that the people in Pachan village, Ubon Ratchathani Province, Thailand, tried to increase the
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the
original work is properly cited.
© 2020 The Authors. Engineering Reports published by John Wiley & Sons Ltd.
Engineering Reports. 2021;3:e12314. wileyonlinelibrary.com/journal/eng2 1of10
2of10 ASVAPOOSITKUL .
FIGURE 1 Schematic
diagram of the experimental
setup for the pump with the
pump head by using the twin column which was placed close to the pump exist as shown in Figure 1. The experiment
on the twin column was conducted at King Mongkut’s University of Technology Thonburi (KMUTT). The results did not
show any improvement in the pump head. However, the installation of the twin column is working as the air chambers
that can avoid damage to the pump system due to water hammer and smooth the flow rate. Therefore, we searched for a
similar invention which could increase a pump head and found that hydraulic ram pump (HRP) might be interested. It
is one of the simplest and the most environmentally friendly devices for such applications.
The idea of using HRP is exquisite and many studies have been done, mostly about the use of a flowing stream for
pumping water to a higher altitude than the point of water supply without an external energy source. Recently, the interest
in HRP for water supply has been renewed due to the awareness of the adverse impact of climate change and the needs of
sustainable technology, especially in remote areas of developing regions.2,3 Comparisons and reviews dealing with HRP
systems can be seen in Watt,4Eric,5Browne,6and Matthias et al.7A comprehensive study on operation and performance
in HRP has been published by Young,8Mbiu et al,9Suarda et al,10 and Asvapoositkul et al.11 Several studies have been
done to investigate HRP especially the effect of impulse or waste valve on the pump performance. The opening and closing
of the waste valve are due to the flow velocity under the action of the supply head. As the flow velocity increases, the disc
of the waste valve rises since the drag of the plate overcomes the weight of the valve. The waste valve will close at some
flow velocity. The closure will be very rapid. This means that the flow in HRP is unsteady flow with complex behavior.
Viccione et al3developed a technique to capture the propagating celerity of the developed pressure waves. Unsteady
pressure profiles at the impulse and delivery valve were detected using pressure transducers. The displacements at impulse
and delivery valves were detected using video recorders. Suarda et al12 also investigated the flow pattern and waste valve
displacements of various designs via a high-speed video camera to analyze the flow structure and reveal the transport
mechanisms in the flows of fluid.
Januddi et al2presented computational fluid dyanmics (CFD) simulations to determine the velocity and pressure
profile for different valves design. The results show the influence of the waste valve on HRP performance. The new design
of HRP with springs system was invented by Rajaonison and Rakotondramiarana.13 Many variables are involved in the
operation of the system. The influence of supply head, air chamber pressure, and waste valve beats per minute on HRP
performance was experimentally determined by Asvapoositkul et al.11 The results reveal that the HRP characteristics
are functions of the waste valve beats per minute and the supply head. It was recommended that the development of
innovative design and application of HRP should be done for further investigation. To the best of our knowledge, HRP is
applied for seawater desalination.14,15
This study focuses on the use of a simple and reliable device to increase pump head, which requires a higher lift than
can be achieved with a pump. A HRP is installed into the path of the pump exit. The key difference between a conventional
pump and a HRP is that a conventional pump is the provider of force to a fluid stream and a HRP uses the force of the
stream to do its work. There is currently no experience in the development and operation of a combined pump and HRP
for the situation where the pump cannot provide sufficient head. This study is also focused on the technical feasibility,
power consumption, and the limitations of such applications.
The present study is to perform an experimental investigation of the operation of a combined pump and HRP (con-
nected in series) and to make a rational analysis with that of a single pump. It illustrated the case where energy sources
in rivers or streams were not enough to drive HRP and a pump alone could not lift water to the required head. Many
variables are involved in the operation of the pump and HRP, but the ones of primary interest to the designing or oper-
ating engineer apart from pump efficiency are the rate of pumping and the head. Therefore, the analysis herein was to
determine the rate of pumping and the head for any conditions of operation.
ASVAPOOSITKUL . 3of10
FIGURE 2 Schematic
diagram of the experimental
setup for pump
FIGURE 3 Schematic
diagram of the experimental
setup for combined pump and
The experimental setup used a pump driven by an electric motor along with a measurement setup as shown in Figure 2.
It was assembled with a centrifugal pump, ZUZUMI model ZH-2007 (flow rate range: 0-60 L/min, hydraulic head range:
0-7 m) equipped with a built-in motor at a constant speed of 1450 rpm. The water was drawn by the pump and its flow rate
was varied by a valve at the discharge pipe. The polyvinyl chloride (PVC) pipe was used with a nominal diameter of 25 mm
(1 in.) and a length of 5 m. The flow at the supply pipe was rated by an Ultrasonic flow meter. The flow at the discharge
pipe was gathered in a storage tank during the test. Water pressure at the discharge pipe was read by a pressure transducer.
The total head at the discharge pipe was calculated from the measured flow rate and pressure. Power utilization in the
pump was rated by using a single-phase multi-meter.
The combined pump and HRP was set up as shown in Figure 3. The HRP used in this study was the same as the one
used by Asvapoositkul et al.11 It was made of the PVC pipe and fittings. The HRP drive pipe of a nominal diameter of
25 mm was connected to the centrifugal pump discharge. The pump sucks in water from a water tank and adds energy to
the water with a supply head, Hs, and a flow rate, Qs. Water from the pump accelerates along the pipe and flows out around
the open of the waste valve with a flow rate, Qw. A simple weighted waste valve as shown in Figure 4 was used. It was
made of stainless steel with a diameter of 40 mm. The opening and closing of the valve are due to the dead weight on the
valve stem. In this experiment, the dead weight of 116g was applied. The drag of the accelerating water closes the wastes
valve, creating a back surge (water-hammer effect) and an increase in pressure, forcing water to flow through the check
valve, the air-chamber, and the delivery pipe with a delivery head, Hdand a flow rate, Qd. A drop in pressure in a supply
pipe opens the waste valve and the cycle repeats. It should be noted that the HRP utilizes the energy from the supply head,
Hs, and a flow rate, Qsto a delivery head, Hdwhich is higher than Hswith a small amount of water Qdby swift closure of
the waste valve. Typically, a small amount of water will be delivered to the storage tank. Therefore, the nominal diameter
of the delivery pipe was reduced to 12 mm. The measuring devices were the same as those used in the pump testing. The
water pressure at the supply (or drive) pipe and that at the delivery pipe were measured by pressure transducers. The
pressure at the air chamber was read by a Burdon-tube gage. The waste valve motion was recorded with a video recorder
in a smartphone (HUAWEI, model Y7 Pro 1080p@30fps). The video was imported to the computer for processing, editing,
and saving. The waste valve beats per minute were counted. The measuring device specifications are given in Table 1.
The pump performance was tested first. The following procedure was followed. After reaching steady-state conditions, all
data were recorded at every 5-minute interval. A total of three readings were recorded for each measured data and then
the mean value was calculated. The water level in the tank was kept constant in this experiment while the water flow rate
was varied. These data were used to characterize the performance of the pump.
4of10 ASVAPOOSITKUL .
FIGURE 4 Drawing and picture of the waste valve
TABLE 1 Measuring devices specifications
Measurement Instrument Accuracy Resolution
Power Multi-meter ±2% 0.1 V, 0.01 A
Pressure at the drive pipe and the delivery pipe Pressure transducer ±0.25% 0.0001 bar
Pressure at the air chamber Burdon-tube gage — 0.5 bar
Water flow rate at the drive pipe Ultrasonic flowmeter ±0.5% to 2% 0.1 L/min
After finishing the pump test, the HRP was installed as shown in Figure 3. The pump is started with the flow control
valve fully closed. By slightly opening the flow control valve at the delivery pipe, the waste valve was pressed to let the
water flow through it. Adjusting the turning of the control valve until the waste valve started beating. It should be noted
that the waste valve was functioning only at a certain range of flow rate (Qd) during this experiment. It is due to the pump
capacity was over the HRP capacity. For each delivery flow rate (Qd) reading, all data were recorded. Increasing the flow
rate, Qduntil the waste valve stopped functioning. The data were used to characterize the performance of the combined
pump and HRP. It should be noted that the waste valve will function only at a certain range of flow rate, Qd. The flow rate
Qwvaries according to the waste valve features, for example, design of disc, weight. These features were unchanged in
this experiment. A characteristic curve for the combined system is presented to assist in the determination of the design
characteristics of the device.
The flow pattern in HRP is not constant in time but exhibits fluctuation. Thus, all the measured param-
eters are averaged and used for determination system performance. The efficiency of the pump is
ASVAPOOSITKUL . 5of10
FIGURE 5 H-Q curve for the pump and
combined pump and HRP
The efficiency of the HRP is defined as
The efficiency of the combined pump and HRP is defined as
𝜂Pump +HRP =𝜌𝑔𝑄dHd
where H*=head ratio =Hd
Q*=flow rate ratio =Qd
Win =input power
The head ratio (H*) is the ratio of discharge head (Hd) to supply head (Hs) and the flow rate ratio (Q*) is the ratio of
discharge flow rate (Qd) to supply flow rate (Qs). In these experiments, the efficiency of the combined system (ηPump+HRP )
is the ratio of the power added to the fluid to the power used to drive the pump.
5RESULTS AND DISCUSSION
The variation of the head with capacity for pump and that for combined pump and HRP are shown in Figure 5. H-Q
curve of the pump is shown with triangular marks. The head developed by the pump decreases with the flow rate. The
maximum head of 11 m is obtained at a flow rate of 0.42 L/min, while the minimum head of 7 m is obtained at a flow
of 31 L/min. The power consumption for this operation is shown in Figure 6. The pump efficiency curve is shown in
Figure 7. The best operating point with the efficiency of 21% is at the flow of about 30 L/min and the head of 7.5 m. These
results represent a benchmark for comparing the pump and the combined system performance.
In the pump, the flow in the supply pipe can be approximately the same as the delivery pipe. In HRP, the flow in the
supply pipe (Qs) is higher than that in the delivery pipe (Qd)duetoloss(Q
w) at the waste valve. Therefore, the flow rate of
the combined system should be specified clearly. The total head of the combined system, in Figure 5, was plotted against
the discharge flow rate (Qd, shown with circular marks). It is high at low Qdand decreases rapidly at high Qd.Wecansee
that the developed head by the combined system is higher than that by the pump in all range of flow rate. The respective
heads are also plotted as a function of the supply flow rate (Qsshown with square marks). It must be emphasized that the
6of10 ASVAPOOSITKUL .
FIGURE 6 Win-Q curve for the pump and
combined pump and HRP
FIGURE 7 η-Q curve for the pump and combined
pump and HRP
curves presented in Figure 5 delineate the operating points for the pump and the combined system with Qdand Qs.The
flow differential (Qs−Qd) is reflected in quantity wasted, Qw. As a result of this mass flow rate lost, the combined system
performance should be presented in terms of Qd(the actual amount of fluid flowing through the system), and its supply
flow rate, Qs, to see how the energy conversion in the system. Its overall performance is considered in terms of Qdand
Hd, and efficiency dropped with lower delivery flows. However, higher delivery flows Qdcould not be achieved at this
experiment and permitted only about 7 L/min. This is a drawback that needs to be discussed in the following.
The power consumption of the combined system, in Figure 6, was plotted against Qdand Qswhich are shown in
circular marks and square marks, respectively. The power consumption of the combined system as a function of the
quantity delivered Qd(shown in circular marks) was high compare to that of the pump for the same flow rate. However,
the respective power consumption of the combined system as a function of supply flow rate, Qs(shown in square marks)
did not exceed the power consumption of the pump for the same flow rate. This meant that the pump was not overload
when the HRP was added.
ASVAPOOSITKUL . 7of10
FIGURE 8 Head ratio and ηvs the flow rate ratio
of the combined pump and HRP
A similar observation may be made for efficiencies of both cases in Figure 7. It looked like that the combined system
as a function of Qd(shown in circular marks) was improved the efficiency of the pump. The corresponding values as
s(shown in square marks) were substantially low when compared to the pump efficiency. Variations in
these values may be explained by quantity wasted, Qwat the waste valve.
Power supply from the pump (in terms of Hsand Qs) is used by HRP to lift part of water to another level (in terms of
Hdand Qd). It allows us to deal with the higher pressure rise at a less discharge flow rate. The efficiency of the HRP and
that of the combined system are given in Equations (1)-(3). The performance of the machine is best presented in terms of
dimensionless coefficients. These coefficients are the head ratio H*(the ratio of discharge head to supply head), the flow
ratio Q*(the ratio of discharge flow rate to supply flow rate), and the efficiency.11 The relationship between H*and Q*is
*<1 and H*>1. H*is high at low Q*. The more head is required, the less flow can be lifted.
The overall efficiency of the combined system was also shown in Figure 8. These points are discussed further in another
section of the present review.
Different characteristics for the quantity delivered Qd, source capacity Qs, and quantity wasted Qwwere shown in
Figure 9. The results showed that the parameter Qwtrended to vary inversely proportional to Qd. The parameter Qsdid
not appear to be greatly influenced by Qd. Therefore, the less flow in delivery pipe Qdmeans a high flow rate through the
waste valve. All recorded data of Qswere in the range of 30.53 ±0.22 L/min with a confidence limit of 95%. This meant
that the pump was operated around its best operating point during the test of the combined system (as shown in Figure 7).
The parameter Qwwas affected by its beat frequency in terms of beats per minute. This was shown in Figure 10 where
an increase in quantity wasted trended to increase its beats per minute due to the drag of the disc. The beats per minute
were in the range of 197-230 times/min during this experiment. However, an increase in Qwmeant low Qdand η(as shown
in Figures 7-10). Therefore, an increase in waste valve beats per minute value tended to decrease the overall efficiency of
the system. This is in contrast with previously described11 that HRP must be adjusted to pump the maximum quantity
of water possible (Qd), and this normally happens when the waste valve beats per minute value are the highest. In this
experiment, the highest value in the waste valve beats per minute could not be obtained since the pump capacity was over
the HRP capacity. The control valve at the delivery line cannot be varied independently. It must be adjusted to a certain
range of flow rates where the waste valve was functioning. Therefore, the waste valve beats per minute were measured at
a certain flow rate Qdinstead. It should be noted that the results from this experiment demonstrated the potential use of
HRP to increase the discharge head of the pump in case of a shortage of lift.
This study focuses on the technical feasibility of combining the pump and HRP for increasing pump head. The appli-
cation illustrates the case where energy sources in rivers or streams are not enough to drive HRP and the pump alone
cannot lift water to the required head. This means that both are required to accomplish the case. The study addressed
three primary research questions.
8of10 ASVAPOOSITKUL .
FIGURE 9 Flow rate in supply pipe and waste
valve vs delivery flow rate
FIGURE 10 Waste valve beat frequency vs
The first question focused on the feasibility of combining the pump and HRP for increasing pump head. The results
indicate that the combined system (pump +HRP) can boost the head ratio of 2.4-7, but at the expense of the flow rate ratio
(eg, 0.23-0.02). This means that the output head is 2.4-7 times the input head where only 23%-2% of the water flowing
through the system will be delivered to the storage tank. The results also indicate that the combined system efficiency
is low compared to the pump efficiency as a function of supply flow rate Qs(square marks in Figure 7). We noticed that
HRP could smooth the pressure from the pump during the test run.
The second research question evaluated the power consumption of the combined system and that of the pump. Again,
it should be considered in terms of the supply flow rate (Qs). The results indicated that the hydropower from the pump
was used by HRP to increase discharged head but at a lesser flow rate. It did not overload the pump and continuously
works if the hydropower from the pump was available.
The third research question addressed the limitation of the combined system. Normally, in each supply head condition,
the HRP is adjusted to pump the maximum flow Qdin the delivery pipe with an approximately constant value of waste
ASVAPOOSITKUL . 9of10
valve beats per minute.11 However, this could not be done during this experiment because the pump capacity was over
the HRP capacity. The waste valve was functioning only at a certain range of flow rate (Qd). Therefore, the waste valve
beats per minute were measured at a certain flow rate Qdinstead. This indicates that the pump and the HRP should be
matched for optimal work output and waste valve beats per minute.
The efficiency of the HRP is appreciably lower than that of the electric pump. The comparatively low value of efficiency
should not be considered prejudicial to the HRP, because the power sources of the two systems are different. The input
power of the electric pump is the electricity which is normally much more valuable and expensive. The input power of the
HRP is the hydropower from the stream or the pump in this case study and does not need other power sources to operate.
The HRP is used because of its simplicity of construction, inexpensive, and no harmful effects on the environment.
The possibility of using HRP to increase head for the pump in case of a shortage of lift or work as a booster pump
has been investigated. The experimental results show that this simple device can be used to increase water-lift with a
high head (2.4-7 times the input head) at a less flow rate (23%-2% of the supply flow rate). The pump was working nor-
mally, and no overloading was found. The combined system efficiency is lower than the pump efficiency in terms of
supply flow rate since most of the water is wasted at the waste valve. The required head and water flow rate influence
the combined system performance. These parameters were considered in terms of head ratio (H*) and flow rate ratio
(Q*). There is a limitation that the system can be used. The pump and the HRP should be matched for optimal work
output and waste valve beats per minute. Optimum pump efficiency is governed by H*and Q*. The impact of these
parameters on such applications comes with a trade-off. Finally, the system could be applied to increase the pump head.
Potential future applications for climate change and sustainability technologies for developing areas. The combined sys-
tem works with relatively low system efficiency. Therefore, an investigation of potential improvement is required. It
must be determined for the water demands where it is applicable since more than 75% of the supply water is wasted
at the waste valve. The authors suggest that future research should be focused on assessment methods in matching
the pump and the HRP for optimal work output and waste valve beats per minute. Investigation on the new design of
HRP, as suggested by Rajaonison and Rakotondramiarana13 and Obermoser,16 could be done in eliminating the loss of
flow rate in the waste valve. Numerical analysis of the complex behavior of HRP systems also recommended especially
of the opening and closing condition of the wasted valve. As already pointed out in the introduction, flow visualiza-
tion techniques combined with measured pump performance results help to get a better understanding of flow patterns
The authors gratefully acknowledge the support of King Mongkut’s University of Technology Thonburi for the study.
PEER REVIEW INFORMATION
Engineering Reports thanks Giacomo Viccione and other anonymous reviewers for their contribution to the peer review
of this work.
CONFLICT OF INTEREST
The authors declare no potential conflict of interest.
Wanchai asvapoositkul: Writing-review and editing. T Nimitpaitoon: Data curation; resources. S. Rattanasuwan:
Formal analysis; resources. P Manakitsirisuthi: Data curation; resources.
DATA AVAILABILITY STATEMENT
The data that support the findings of this study are available from the corresponding author upon reasonable request.
Wanchai Asvapoositkul https://orcid.org/0000-0001-6525-1888
10 of 10 ASVAPOOSITKUL .
1. Brikké F, Bredero M. Linking Technology Choice with Operation and Maintenance in the Context of Community Water Supply and Sanitation:
A Reference Document for Planners and Project Staff . Geneva, Switzerland: World Health Organization; 2003.
2. Januddi FS, Huzni MM, Effendy MS, Bakri A, Mohammad Z, Ismail Z. Development and testing of hydraulic ram pump (Hydram):
experiments and simulations. The International Fundamentum Sciences Symposium. Vol 440. Bristol, England: IOP Publishing Ltd; 2018.
3. Viccione G, Immediata N, Cava R, Piantedosi M. εA preliminary laboratory investigation of a hydraulic ram pump. Paper presented at:
The 3rd EWaS International Conference on “Insights on Water-Energy-Food Nexus; 27–30 June 2018; Lefkada Island, Greece.
4. Watt S. A Manual on the Automatic Hydraulic Ram for Pumping Water. London, UK: Intermediate Technology Publications; 1975.
5. Eric J. Proceedings of a Workshop on Hydraulic Ram Pump (Hydram) Technology Manuscript Report; May 29–June 1, 1984; Arusha,
6. Browne D. Design, Sizing, Construction and Maintenance of Gravity-Fed System in Rural Areas, Module 6: Hydraulic Ram Pump Systems
Action. Paris, France: Contre la Faim, Hermann; 2005.
7. Matthias I, Suchard S, Johannes FJM, Johannes M, S W. Hydraulic ram pumps for irrigation in northern Thailand agriculture and
agricultural. Sci Procedia. 2015;5:107-114.
8. Young B. Design of Homologous ram Pump. J Fluids Eng Trans ASME. 1997;119:360-365.
9. Mbiu RN, Maranga SM, Mwai M. Performance testing of hydraulic ram pump. Paper presented at: Proceedings of the Sustainable Research
and Innovation (SRI) Conference; 6–8 May 2015. ISBN: 2079-6226.
10. Suarda M, Ghurri A, Sucipta M, Kusuma IGBW. Investigation on characterization of waste valve to optimize the hydraulic ram pump
performance. Paper presented at: AIP Conference Proceedings 1984; 2018:020023.
11. Asvapoositkul W, Juruta J, Tabtimhin N, Limpongsa Y. Determination of hydraulic ram pump performance: experimental results. Adv
Civil Eng. 2019;2019:1-11.
12. Suarda M, Sucipta M, Dwijana IGK. Investigation on flow pattern in a hydraulic ram pump at various design and setting of its waste valve.
Paper presented at: International Conference on Design, Energy, Materials and Manufacture; 2019:539.
13. Rajaonison A, Rakotondramiarana HT. Theoretical study of the behavior of a hydraulic ram pump with springs system. Am J Fluid Dynam.
14. Sawyer RA, Maratos DF. An investigation into the economic feasibility of unsteady incompressible duct flow (water hammer) to create
hydrostatic pressure for seawater desalination using reverse osmosis. Desalination. 2001;138:307-317.
15. Sawyer RA. Technical feasibility of wave power for seawater desalination using the hydro-ram (Hydram). Desalination. Vol 153.
Amsterdam, Netherlands: Elsevier BV; 2003:287-293.
16. Obermoser K. Hydraulic ram pump. USA Patent US 6,234,764 B1, 2001.
How to cite this article: Asvapoositkul W, Nimitpaitoon T, Rattanasuwan S, Manakitsirisuthi P. The use of
hydraulic ram pump for increasing pump head-technical feasibility. Engineering Reports. 2021;3:e12314. https://