Solenoid Valve
A solenoid valve is an electromechanically operated valve in which an energised coil generates a magnetic field that moves a plunger to open or close an orifice. Direct-acting valves move the seal directly and can operate from zero pressure differential, while pilot-operated (servo-assisted) valves use line pressure to open a larger main orifice and require a minimum pressure differential. Configurations include 2/2-way for on/off flow, and 3/2-way and 5/2-way for directing air to pneumatic actuators and cylinders; valves may be normally closed or normally open. Typical uses include water and air shut-off, fuel gas trains, instrument air control of valve actuators and machine automation. Selection considers port size, flow coefficient, pressure range, media compatibility, coil voltage (AC or DC), duty cycle, ingress protection and certification for hazardous areas, for example to IEC 60079.
Examples
- 3/2-way solenoid valve piloting a spring-return valve actuator
- Normally closed solenoid valve in a burner fuel gas train
- 2/2-way solenoid valve for irrigation water shut-off