Through education and technology we endeavor to teach industry, analytical thinking and ingenuity, which could be considered building blocks upon which they could become self-sufficient to the point of creating revenues, which could then be used to reach out to other communities in need.
To create a grassroots level organization that in due time could operate independent of outside support. We would want to see this organization utilizing technology fueled by natural energy from the sun, wind and water.
In 1999 we wanted to supply water to a children's home, located high up in the mountains of Northern Thailand. Initially, we deployed a conventional gasoline-powered water pump, which, quite predictably, proved to be by far too costly, both in running and maintenance terms.
We subsequently discovered the ram pump concept and purchased a number of commercially available units, some of which failed miserably to deliver water to our site 20 meters above and 800 meters away from a fresh-water stream. Hence, we decided to develop our own pump from standard fittings, including all kinds of check valves, in combination with various types of metal, PVC, PE & PU fittings, etc.
While we did experience that we could deliver sufficient water, there were a number of negative experiences:
1. High wear and tear of valves and system
2. Excessive noise
3. Inconsistent output
These challenges made us look into the ram pump technology in great detail, as the need to meet the children’s needs had created an obsession on our part; the time had come to ”master” ram pump technology. We began to research the principles of ram pumping technology, and built a test site that allowed us to change many parameters, including various high- and low-tech materials like Kevlar, nylon, Teflon, non-ferrous and ferrous steels and others. That was the time when Meribah Ram Pump becomes a social enterprice.
Our goal was to devise a long-lasting, virtually maintenance-free pump that could deliver a huge volume of water to a high elevation. The pump had to be constructed from heavy-duty material, yet still be affordable to people in resource-poor settings.
While we carried out tests on our prototypes, we discovered that all the aggregated information on ram pumps sourced from books and websites was either incomplete or simply failed to adequately explain the differing results observed. In the course of extensive empiric test series, we assessed the pumps under all kinds of conditions. We even ventured into quantum physics in an attempt to find possible answers to the results that could not be explained by existing mathematical concepts.
Over a period of 10 years of hands-on-experience, we invented our own unique valve technology, which had never before been used in ram pumps. Notwithstanding these significant advances, we are convinced that the ram pump technology is to experience further development and optimization.
We would therefore appreciate all input from others, regarding their own experiences with these pumps. Our core objective is to be able to provide the underprivileged people in rural areas with simple, robust and affordable water transport systems to free up valuable resources, eliminate the hazards of water contamination and diseases, and to improve standards of living.
A hydraulic ram pump harnesses the power of the water hammer, the so called "ram", created by the gravitational flow of the water and the immediate stopping through a valve. The so-called "ram" which gave the ram pumps their name.
The developed power is used to lift a fraction of the total water, which is needed to power the pump, above its very origin. It is commonly used in remote areas with access to water level differentials, since it requires no outside source of power other than the gravitational energy of falling water.
The first ram pump was invented in 1796 by the Frenchman Joseph Michel Montgolfier for the purpose of raising water in his paper mill at Voiron. His friend Matthew Boulton took out a British patent on his behalf in 1797. The sons of Montgolfier obtained an English patent for an improved version in 1816.
A hydraulic ram pump has only two moving parts:A mostly weight loaded waste valve, sometimes known as the clack valve and a delivery check valve, which makes the pump operation reliable and easy to maintain.
Other non-moving parts are the drive pipe which supplying water from an elevated source and a delivery pipe, taking a portion of the water that comes through the drive pipe to an elevation higher than the original water source.
Click on the image to see an animation
At the beginning of the cycle, the waste valve (4) is open and the delivery valve (5) is closed. The water in the drive pipe (1) starts to flow by gravitational force, picks up speed and kinetic energy until it forces the waste valve to shut close.
The momentum of the water flow in the drive pipe (1) against the presently closed waste valve (4) creates a so-called water hammer, which raises the pressure inside the drive pipe (1) and the pump body and thus opens the delivery check valve (5).
This allows a portion of the water under pressure to escape into the pressure vessel (6) and the delivery pipe (3). Since this water is being forced through the delivery pipe (3) against gravity, its flow slows down and finally reverses, closing the delivery check valve (5) closes. If all water flow has stopped, the pressure inside the drive pipe (1) equals ambient pressure, which makes the waste valve (4) reopen to allow the above cycle to start again.
When commencing operation for the first time, or after long periods of inactivity, the pressure vessel (6) contains an air cushion, only. The latter cushions the sudden build-up of pressure, when the waste valve (4) shuts close and improves efficiency by allowing a more constant flow through the delivery pipe (3).
Although the pump could work without any pressure vessel (6), its efficiency would drop drastically and the pump structure would be subject to extraordinary stress that shortens its life considerably. As the air in the pressure vessel (6) is under pressure, it tends to disappear gradually through the delivery pipe (3). That could be solving by installing a snifting valve between pump body and pressure vessel (6).
The optimum length of the drive pipe (1) is 2 to 5 times the vertical distance between the source and the pump. With these parameters, pump cycles typically are 40 - 60 beats per minute. In order to optimize efficiency, the drive pipe (1) should be made of non-elastic, strong and rigid materials and installed as straight as possible and fixed properly on the ground.