Structural features and operating principle

Hydraulic control valves are generally divided into diaphragm type and piston type. The working principles of both are the same. Both hydraulic control valves are powered by the upstream and downstream pressure difference △ P and controlled by the pilot valve, so that the diaphragm (piston) is hydraulically operated in a differential manner and completely adjusted automatically by hydraulic power, so that the main valve disc is fully opened or closed, or in a regulated state. It is composed of a main valve (as shown in Fig. 1 and Fig. 2) and its external needle valve, pilot valve, conduit and pressure gauge. It has evolved into remote-controlled float valve, pressure reducing valve, slow closing check valve, flow control valve, pressure relief / pressure holding valve, hydraulic electric control valve, constant water level valve, water pump control valve / emergency shut-off valve, etc. according to different purposes, functions and places.

Materials of main parts: