Hydraulic Ram Pumps (Hydram)
Using the natural power of water to pump itself to mountain communities
What is a hydram?
The hydraulic ram pump – commonly referred to as a hydram – pumps water from its source to a community. It utilises the natural power of falling or rapidly moving water, meaning the hydram requires zero external energy supply to operate. This process works on a principle called ‘water hammer’, where a large amount of quickly moving water is pushed through a small opening to create pressure. As pressure builds within the system it reaches a critical point that then lifts a fraction of the water flow. These smaller amounts of water are repeatedly lifted and ultimately collected in a storage tank placed above a community. The storage tank then feeds water back down to the community using gravity. A single hydram can lift water up to 200 vertical metres and supplies roughly 20,000 litres of water per day (enough to fill 250 baths) to a community.
Hydrams are unique for their simplicity, durability, and virtually cost-free operation. They are affordable because their power comes from the very water they provide. They are simple because they are constructed of only 2 moving pieces: a delivery valve and a waste valve. This simple design means they can be primarily constructed with strong materials like steel. It also means they can be constructed and repaired using recycled, everyday objects. For example, new and replacement valves can be made using old car tyres and door hinges. Finally, if well-designed, the system can redirect unused water back to the original water source. This means a community can receive the free gift of convenient and reliable water lifted to their community without any waste.
Where is the hydram appropriate?
Hydrams are particularly useful in remote mountainous regions where communities live high above their nearest water source. This allows people to save valuable time since they no longer have to go on faraway journeys to water sources via dangerous mountain paths. Most importantly, hydrams require a high-volume water source to operate effectively. This is because the hydram only lifts a small fraction – roughly 10% – of the water that flows through the pump. It therefore does not make sense to install a hydram at a small stream. In cases of lower-volume water sources, a SolarMUS system makes more sense!
Did you know that we have installed hydrams in 13 communities in Nepal? This means convenient, reliable water for more than 2,500 people. These pumps continue to lift more than 260,000 litres of water (the equivalent of filling 3,250 baths) per day. Families no longer spend hours fetching water. This means more time for business, school, and play. Read more about the impacts of our hydram systems in Nepal.
How does the hydram really work?
A hydram pump works by using the momentum of falling water to pump a small quantity of that water high above its source.
- The pump is placed below a water source and connected to it with a pipe, called a drive pipe. Gravity feeds the water down the drive pipe to a chamber in the pump.
- Two valves provide possible exits to the chamber. These are the waste valve and the delivery valve. The waste valve is set up so that it is normally open, but high pressure in the chamber forces it shut. The delivery valve is set up so that it is normally closed, but high pressure in the chamber forces it open.
- Water flows into the chamber and flows out freely though the waste valve. This free flow allows the water to build up speed.
- As more and more water flows faster and faster through the chamber, it exerts more and more pressure on the waste valve until the waste valve slams shut.
- The water now has no exit from the chamber, but more water is still entering it at high speed. The pressure increases rapidly. This is where water hammer happens.
- The increasing pressure forces the delivery valve to open. The water flows through the delivery valve into a chamber full of compressed air, which sits at the bottom of a second pipe, called the delivery pipe.
- The compressed air exerts pressure on the water, forcing it up the delivery pipe, which carries the water up to its destination.
- With the water forced out of the pump, the pressure drops. The delivery valve closes, and the waste valve reopens.
- The cycle repeats and water is gradually collected in the storage container above. Water is then distributed to households, business, and farms on-demand using a gravity-fed pipe system.
Here is a link to a video that explains the Hydram system in detail. We do not own the rights to the video.
Hydram technology is a fantastic renewable energy solution! However, it isn’t sustainable or profitable without the direct involvement, training, and cooperation of communities. This is why we put communities at the centre of our work. We work with them from day one to create a long-term vision and management plan. Read more about how we work alongside communities as hand-in-hand partners.