Solenoid valve is an industrial equipment controlled by electromagnetism. Solenoid valve is an automatic basic element used to control fluid. solenoid valve belongs to actuator and is not limited to hydraulic and pneumatic. It is used to adjust the direction, flow, speed and other parameters of the medium in the industrial control system. The solenoid valve can cooperate with different circuits to achieve the expected control, and the control accuracy and flexibility can be guaranteed. There are many kinds of solenoid valves. Different solenoid valves play a role in different positions of the control system. The most commonly used are one-way valve, safety valve, direction control valve, speed regulating valve, etc.