How a Water Ram Pump Works

A water ram pump, also called a hydraulic ram, operates by using a source of flowing water as its energy supply. The main components of a hydraulic ram are the delivery pipe, a pair of valves, and an enclosed air and water chamber.

How it Works

A hydraulic water ram pump is constructed of a pipe through which water flows. The device has a water inlet and outlet. The pipe is connected to the inlet, where an adjustable valve lets water from the pipe leak out. The leakage is part of the design of the pump.

As water builds up in the pipe it creates a strong force, applying more pressure to the first valve, eventually causing it to close. When the valve has shut, the water moves to the inside of the pump in the direction of the enclosed chamber.

However, the path to the chamber contains a second valve, located where the water passes into the chamber. Again, water pressure forces the second valve to open just as it closed the first valve.

When the first valve closes and the second valve opens, the water rushing out of the drive pipe moves into the chamber area. When the water floods into the enclosed chamber, it leaves an air pocket trapped inside. The water building up inside the chamber compresses the air pocket. This compressed air forces the water through the pump toward the outlet.

As the water moves through the pump, the pressure begins to drop, which causes the first valve (the one located inside of the delivery pipe) to reopen. The second valve is also forced closed by the drop in pressure.

Although no water is entering the chamber at this time, due to the second valve being closed, water continues to flow out of the outlet of the pump. Pressure from the trapped air pocket continues to push water out of the outlet.

The second valve, located just before the air and water chamber, remains closed. This causes water coming down the drive pipe to build up the pressure again.

This process keeps repeating. The pressure builds up once again, forcing the first valve to shut and the second valve to open. The process continues as more water enters the air and water chamber, causing the air pocket to re-pressurize.

The cycle continues over and over again, with the valves opening and closing, as long as there is enough water to enter the drive pipe. The pump continues to transfer water out the outlet in a continuous stream. The flow is allowed to continue because of the pocket of trapped and compressed air in the inner chamber.


This type of pump is ideal for pumping water to a higher elevation above the water source and the pump location. With this type of pump, you can send water to an elevated holding tank to be used at a later time.