  a hydraulic ram, or hydram, is a cyclic water pump powered by hydropower. it takes in water at one "hydraulic head" (pressure) and flow rate, and outputs water at a higher hydraulic head and lower flow rate. the device uses the water hammer effect to develop pressure that allows a portion of the input water that powers the pump to be lifted to a point higher than where the water originally started. the hydraulic ram is sometimes used in remote areas, where there is both a source of low-head hydropower and a need for pumping water to a destination higher in elevation than the source. in this situation, the ram is often useful, since it requires no outside source of power other than the kinetic energy of flowing water. == history ==  in 1772, john whitehurst of cheshire, united kingdom, invented a manually controlled precursor of the hydraulic ram called the "pulsation engine" and installed the first one at oulton, cheshire to raise water to a height of . descriptions of whitehurst's and montgolfier's pumps appear in: james ferguson and david brewster, lectures on select subjects â¦ , 3rd ed. (edinburgh, scotland: stirling & slade, etc., 1823), vol. 2, pages 287-292; plates, p. 421. in 1783, he installed another in ireland. he did not patent it, and details are obscure, but it is known to have had an air vessel. 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 for raising water in his paper mill at voiron. his friend [[mat
Liquid-piston_pumps Pumps Water