Solenoid valve

A solenoid valve is an electromechanically operated valve used in heating systems, fuel pipelines, and industrial automation to regulate the flow of liquids or gases. It works by passing electric current through a coil of wire, which creates a magnetic field. The magnetic field attracts a plunger, which operates the valve mechanism, to open or close fluid passages.

Solenoid valves differ in the characteristics of the specific electric current in which they use, the strength of the electromagnetic field that they generate, the mechanism they use to regulate the fluid, and the type and characteristics of fluid they control. The mechanism varies from linear action, plunger-type actuators to pivoted-armature actuators and rocker actuators. The valve can use a two-port design to regulate a flow or use a three or more port design to switch flows between ports. Multiple solenoid valves can be placed together on a manifold. The valve mechanism operated by the force of the magnetic plunger may be a spool valve, or a poppet-style valve. Simple solenoids may use a spring to return the valve to the idle position; more complex valves may have two or more coils to move a spool valve. Proportional valves allow a varying electrical current to adjust the position of a valve over a range, which can be used to control flow and thus speed of fluid power devices.

Solenoid valves are the most frequently used control elements in fluidics. Their tasks are to shut off, release, dose, distribute or mix fluids. They are found in many application areas. Solenoids offer fast and safe switching, high-reliability, long service life, good medium compatibility of the materials used, low control power and compact design.