A hydraulic ram pump is a simple kinetic pump often used in remote areas without power. This pump is special in that it may move water to a higher elevation without the use of power. It relies solely on the weight of the water in the pipes to move the parts and push the water. This system may work for years with little or no maintenance, but if something goes wrong in any main area of the system, it is likely that the pump will stop working completely.
The earliest ram pumps were created in the late 1700s and early 1800s. These original models were less reliable than the later versions and were quickly discontinued. By the mid-1800s, a pump that is essentially the same as the one used today came onto the market.
The hydraulic ram pump was all the rage in England, and many remote houses had them installed as a water source. A significant number of those pumps are still in operation. Interest dropped as electric pumps came on the market. In the mid-1900s, interest returned when they were used as a water movement system in developing countries.
The operation of a hydraulic ram pump is quite simple. It all centers on an effect called a water hammer. A water hammer is caused when moving water is stopped suddenly. The pressure that water exerts on its surroundings increases dramatically for a few seconds. This sudden increase in pressure is harnessed as power to make the pump work.
The first step in a hydraulic ram pump is bringing in flowing water. This water needs to have a desire to move on its own, so the initial water source is typically higher than the pump. This water flows through a drive pipe that is capped on one end by a waste valve. The force of the water pushes the valve closed and initiates a water hammer, which causes the pressure in the hydraulic ram pump to increase. This increase in pressure opens a one-way valve, and an amount of water flows through it.
When the hammer effect fades, the water pressure drops and the valve closes, trapping some of the water on the other side. The flow in the drive pipe stops, and the waste valve reopens. This allows water to move again, and that moving water closes the waste valve. This process continues as long as the there is a continuous source of water.
A small amount of water pushes its way into the delivery pipe on the other side of the valve. The water in the delivery pipe slams against the now closed valve and initiates its own water hammer. To absorb this effect, a hydraulic ram pump has a bottle connected to the pipe. This bottle fills and drains with changes in the water pressure. The delivery pipe takes water where it needs to go, even uphill.