Electromagnetic Valve is an Electromagnetic control of industrial equipment, is used to control the fluid automation basic components, belongs to the actuator, is not limited to hydraulic, pneumatic. Used in industrial control systems to adjust the direction, flow rate, velocity, and other parameters of the medium. SOLENOID valve can cooperate with different circuits to achieve the desired control, and control accuracy and flexibility can be guaranteed. There are many kinds of solenoid valve, different solenoid valve in the control system at different locations to play a role, the most commonly used is one-way valve, safety valve, direction control valve, speed control valve, etc. . Principle of operation there is an airtight cavity in the solenoid valve, with through holes in different positions, each hole is connected to a different oil pipe, the middle of the cavity is a piston, two electromagnets on both sides, which side of the magnet coil will be attracted to which side of the valve body, by controlling the movement of the valve body to open or close different drain holes, and the oil hole is always open, the hydraulic oil will enter different drain pipes, and then through the oil pressure to push the piston cylinder, the Piston in turn moves the Piston Rod, piston Rod driven mechanism. Thus by controlling the current of the electromagnet, the mechanical motion is controlled.