Introduction
The hydraulic ram pump, or hydram, concept was first developed by the Mongolfier brothers in France in 1796 (they are better remembered for their pioneering work with hot-air balloons). Essentially, a hydram is an automatic pumping device which utilizes a small fall of water to lift a fraction of the supply flow to a much greater height; ie. it uses a larger flow of water falling through a small head to lift a small flow of water through a higher head. The main virtue of the hydram is that its only moving parts are two valves, and it is therefore mechanically very simple. This gives it very high reliability, minimal maintenance requirements and a long operation life.