Hydraulic Ram

Machine for raising water to heights by means of the living force of that water as its flow is arrested suddenly in a descending closed channel; invented by by Montgol- Mo fier, 1796. When a column of water flowing by gravity in a pipe through an opened valve is suddenly arrested by the closure of that valve, a water-hammer is observed. The flowing water in the pipe has a certain living force, due to its motion, and this is given out, especially at the closed end of the pipe, to exert a considerable strain there. That pre ure is sufficient to open a valve in a column pipe, which valve is held down by the head of water on its upper side, and to allow some of IMG:content-0700.png:[graphic][merged small] the arrested water to force its way into the filled column. The water being at rest, when equilibrium is restored, the first valve can be made to open and re-establish the flow. This is done by having the first valve a check-valve seating upward, and so weighted in proportion to its area as to fall open by its own weight when the descending fluid is at rest, but in the moving current flowing through the opening it will be floated shut and stop the flow. The establishment of the flow is the occasion of waste by leakage, but ordinarily, under average lifts, these rams will lift ab. one-third of what flows in the actuating current.