The hydraulic control valve is to use the pressure of media as the driving force to open and close, regulating valve. It consists of a main valve and attached to the pipes, needle valve, ball valve and pressure gauge, according to the service purpose or different functional places, it can be evolved into a remote control float valve, pressure reducing valves, slow closing check valve, flow controller, pressure relief valve, hydraulic electric control valves, emergency shut-off valve and so on.
Pilot valve is worked by the hydraulic flow level and pressure difference of the media. As there are many different types, pilot valve can be used alone or in several combinations to use, you can make the main valve on the water level and water pressure and flow alone and in complex control function. But the main valve body similar to the cut-off valve when the valve is fully open, the pressure loss is much greater than other valves, and each opening loss coefficient is more close to the fully closed state, the more dramatic increase in the valve bore more large the more remarkable.
Valve with the above characteristics, accelerated close to the action of the valve flap, easy to the impact of water hammer, close to the fully closed position, the valve moves, the slower the better, so it may set the throttling device in the valve. In addition, the pilot valve should avoid setting the special small diameter orifice to prevent blockage. When necessary to add filters, regular maintenance and/or setting of the bypass pipe with valve. Hydraulic control valve has two types, one is diaphragm type and another is piston type. They are the the same work principle, they are worked by pressure difference between upstream pressure and downstream pressure as the driving force, the pilot valve has piping control to operate diaphragm (piston), fully automatic adjustment by hydraulic, so that the main valve disc fully open or fully closed or in regulation situation. It can be used for human water supply, fire safety systems and industrial water supply system.