Abstract: A compressor utilizes a fluid piston to achieve high volumetric efficiency and produce moisture-free, clean, compressed fluid. The compressor has two hollow chambers which are interconnected by a conduit system having a pump located in it. The compressor contains a sufficient volume of noncompressible transfer fluid to completely fill one of the cylinders and the conduit system. A switching system causes the pump to pump the transfer fluid into a first chamber until that chamber is completely filled and then pump the transfer fluid out of the first chamber and into the second chamber. When the second chamber is completely filled the switching system again causes the direction the transfer fluid is being pumped to reverse and the cycle is repeated.

Abstract: The apparatus of the present invention is comprised of transfer tanks which are located below the hydraulic head of a dam. Connected to the transfer tanks are air inlets extending from the transfer tanks to the atmosphere, and having check valves located therein. A water inlet and valve, interconnect the transfer tanks with the fluid behind the dam, and a water outlet and valve empty the transfer tank downstream of the dam. A storage tank is interconnected to the transfer tank by transfer lines having check valves at their transfer tank ends, and a turbine outlet extends from the storage tank to an air driven turbine. In one embodiment of the invention two transfer tanks and one open-bottomed storage tank are located on the upstream side of the dam at its base. In this embodiment water outlets pass from the bottom of the transfer tanks through the face of the dam.