تسجيل الدخول

تسجيل

The Lifting Pump

المؤلف:  GEORGE A. HOADLEY

المصدر:  GEORGE A. HOADLEY

الجزء والصفحة:  p-182

2025-11-12

468

There is practically no difference between the suction or lifting pump and the simple air pump. In both the valves open upward and should be air-tight. From the base of the cylinder of a lifting pump a tube runs to the water supply, and near the top of the cylinder is a spout for carrying off the water. When the pump is started, the air is first pumped out. On the up stroke of the piston, pressure is removed from the top of the lower valve and atmospheric pressure causes water to rise in the tube T, finally filling the space below the piston. On the down stroke of the piston the lower valve closes, holding the water above it. Water is forced through the piston valve. On the next up stroke of the piston, water is lifted out (Fig. 1). It will be seen that the upper valve must be placed so that its highest position shall not be more than 34 ft. above the level of the water in the cistern. About 27 ft. is the practical limit.