Principle of Pump Control Valve

When the pump is started, the solenoid pilot valve is fully opened after electrification, and adjust the needle valve to the appropriate opening degree, upstream water enters the main valve control room through the pipe and flows out through the solenoid pilot valve, at this point, the pressure of the main valve control room keeps the main valve open and at the appropriate opening degree to keep the normal water supply downstream. When the water pump stops working, the solenoid pilot valve closed after power is cut off, the main valve control room stops to drain, the pressure of the control room rise, the main valve begins to close. When close to 90% position, the upper routing switch of the main valve outputs the stop signal and the pump stops running. At this point, the downstream backwater enters the main valve control room through the pilot pipe, the pressure of the control room increases to close the main valve.