Solenoid valve overview

Solenoid valve is an automation basic element used to control fluid and belongs to actuator; it is not limited to hydraulic and pneumatic. Solenoid valves are used to control the direction of hydraulic flow. Plant machinery is generally controlled by hydraulic steel, so solenoid valves are used.

Working principle: There are sealed chambers in the solenoid valve. There are through holes in different positions. Each hole leads to a different tubing. The middle of the chamber is a valve. The two sides are two electromagnets. Which side of the magnet coil energizes the valve body. Which side will be attracted, by controlling the movement of the valve body to block or leak out different oil discharge holes, and the oil inlet hole is normally open, the hydraulic oil will enter different drain pipes, and then pass through the oil pressure To promote the piston of oil, the piston also drives the piston rod, which drives the mechanical device to move. This controls the mechanical motion by controlling the electromagnet current.

classification

Direct acting solenoid valve:

Principle: When the power is turned on, the electromagnetic coil generates an electromagnetic force to lift the closing member from the valve seat and the valve opens. When the power is turned off, the electromagnetic force disappears. The spring presses the closing member against the valve seat and the valve closes.

Features: It can work normally under vacuum, negative pressure and zero pressure, but its diameter is generally not more than 25mm.

Distributed direct-acting solenoid valve:

Principle: It is a combination of direct acting and pilot type. When there is no pressure difference between the inlet and the outlet, the electromagnetic force directly lifts the pilot small valve and the main valve closing part and the valve opens. When the inlet and outlet reach the starting differential pressure, after the power is turned on, the electromagnetic force leads the small valve, the pressure in the lower chamber of the main valve rises, and the pressure in the upper chamber decreases, thereby pushing the main valve upwards by utilizing the pressure difference; when the power is off, the pilot valve utilizes the spring. Force or medium pressure pushes the closure and moves it downwards to close the valve.

Features: It can also operate at zero differential pressure or vacuum or high pressure, but it requires a large amount of power and must be installed horizontally.