GERAET ZUM STEUERN DES DURCHFLUSSES EINER FLUESSIGKEIT.

摘要

Apparatus for controlling the flow of water through a pipe including a valve and an orifice plate and supplying a water distribution system comprises a governor actuating a pilot valve in a servo system controlling the valve. The governor has two diaphragms linked by a tension spring the extension of which is determined by the rate of flow through the orifice plate. The first diaphragm operates a valve member of the pilot valve and is subjected to the differential pressure caused by flow through the orifice plate. The second diaphragm is loaded by a compression spring and its displacement is dependent upon the control pressure at a tapping in the pipe. The movement of the valve member is the combination of the displacements of the two diaphragms, and raises the control pressure at tapping when demand for water increases. In a modification the two diaphragms are housed in separate compartments, the first diaphragm is loaded by the tension spring against differential pressure and the displacements of the two diaphragms are combined at the pilot valve, the first diaphragm moving the valve body and the second diaphragm to the valve member. The governor may also serve as a sensitive pressure reducing valve without flow compensation, the differential pressure on the first diaphragm being derived from rate of change of pressure in the pipe and produced by throttling an impulse pipe by which a component of the differential pressure is applied to one side of the first diaphragm.