A Hydraulic Ram Pump, aka Water Hammer, is a pump that uses only gravity to move water. The first self-acting ram pump was invented by the Frenchman Joseph Michel Montgolfier, best known as a co-inventor of the hot air balloon, in 1796. He needed a pump to raise water in his paper mill at Voiron France. When water quickly changes direction due to a valve closing it creates a hammer effect. This sudden release of pressure will make a sound like a hammer hitting the pipe. By using two opposing valves this effect can be created intentionally to capture the force of the moving water to direct it towards another valve and once set into motion it can lift water 10 times the height of the original source. These pumps were widely used around the world until the early 1900's when they were replaced by electric pumps. Today ram pumps are making a comeback similar to how the electric car, an idea first launched in 1911 is making a comeback.
We built a hydraulic ram pump using PVC pipe that we use in our presentations. Here are links to plans to make your own and a link to our youtube video showing the pump in action. Youtube Video Wikipedia - Hydraulic Ram