The solenoid valve uses an electromagnetic coil to control the position of the valve core to achieve the purpose of changing the direction of fluid flow, or to cut off or connect the air source.
The electromagnetic component of the commonly used four-way solenoid valve is composed of fixed iron core, moving iron core, coil and other parts. The valve body part consists of a sliding valve core. The valve body, slide valve sleeve, spring base and other components.
The working principle of the four-way solenoid valve: when a current flows through the coil, an excitation effect is generated, the fixed iron core attracts the moving iron core, and the moving iron core drives the spool valve core and compresses the spring, which changes the position of the spool valve core, thereby changing The direction of the fluid. When the coil is de-energized, the slide valve core is pushed back by the elastic force of the spring, and the iron core is pushed back to make the fluid flow in the original direction. This solenoid valve can be used in a switching system to force the valve to open and close.
The working principle of the three-way solenoid valve: It can be used to switch on or off the gas source, thereby switching the pneumatic control membrane head gas path. It is composed of valve body, valve cover, electromagnetic assembly, spring and sealing structure. The sealing block at the bottom of the moving iron core closes the air inlet of the valve body by the pressure of the spring. After energizing, the electromagnet attracts, the sealing block with spring on the upper part of the moving iron core closes the exhaust port, and the airflow enters the membrane head from the intake port to play a control role. When the power is lost, the electromagnetic force disappears, the moving iron core leaves the fixed iron core under the action of the spring force, moves downwards, opens the exhaust port, blocks the air intake, the membrane head flows out through the exhaust port, and the diaphragm recovers Original location. The three-way solenoid valve can be used in the emergency cut-off of the membrane control valve at the inlet of the turboexpander and the control part of the emergency load of the brake fan.
The working medium of the solenoid valve is filtered clean compressed air, and the working pressure is 0.3～0.5MPa.