Solenoid valve is an industrial equipment controlled by electromagnetic, is used to control the basic components of fluid automation, belongs to the actuator, is not limited to hydraulic, pneumatic. Used in industrial control systems to adjust the direction of media, flow, speed and other parameters. The solenoid valve can be combined with different circuits to achieve the desired control, and the precision and flexibility of the control 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 check valves, safety valves, direction control valves, speed regulating valves and so on.