Water ram Ram pumps are water pumping devices that are powered by falling water. The pump works by using the energy of a large amount of water falling a small height to lift a small amount of that water to a much greater height. In this way, water from a spring or stream in a valley can be pumped to a village or irrigation scheme on the hillside. Where ever a fall of water can be obtained, the ram pump can be used as a comparatively cheap, simple and reliable means of raising water to considerable heights.
Ram pumps have a cyclic pumping action that produces their characteristic beat during operation.
When the impulse valve is open, water accelerates down the drive pipe and discharges through the open valve. The friction of the water flowing past the moving parts of the valve causes a force on the valve acting to close it. As the flow increases it reaches a speed where the drag force is sufficient to start closing the valve. Once it has begun to move, the valve closes very quickly. As the impulse valve slams shut, it stops the flow of water through it.