Abstract: In a method and apparatus for maintaining substantially constant delivery of a fluid pressure medium at lowered pressure from a supply pipe to a utilizing device, the fluid pressure medium is fed through a branch pipe to the device via a prime mover, such as a turbine, which provides the desired pressure drop. If the pressure in the supply pipe falls below a predetermined level, the lowered output of the prime mover is sensed and a shut-off valve in the branch pipe is closed and a press-reducing valve is opened in a bypass pipe connecting the supply pipe to the utilizing device. A flowmeter in the bypass pipe serves to detect rate of flow therein and, upon exceeding of a predetermined rate of flow, to close the pressure-reducing valve and to open the shut-off valve.

Abstract: A power plant for connection to a main pipe conveying a pressure medium such as natural gas, includes a branch pipe connected to the main pipe, an energy conversion device such as a turbine or a piston pump connected to receive pressure medium from the branch pipe and operable to convert pressure energy of the medium into usable energy, and an intermediate buffer reservoir connected to receive pressure medium from the conversion device and supplying the pressure medium from the reservoir to a load which consumes pressure medium.