Solenoid valves are electromechanical valves that are used with liquid or gas. The solenoid valve is controlled by running or stopping an electrical current through a solenoid which changes the state of the valve. A spring or other device may be used to hold the valve open or closed when the valve isn’t activated. Solenoids are devices that turn various types of energy such as electrical, hydraulic and pneumatic into a linear motion. Solenoid valves can be used to isolate, release, dose, control, distribute or mix gases and fluids.
An electric solenoid uses an electromagnet while pneumatic and hydraulic solenoids use a piston assembly and are activated by pressurized fluids or air. Solenoid valves are made of various types of materials such as aluminum, plastics, brass, bronze, ductile iron, copper, stainless steel, and sheet metal, etc. Solenoid valves are made of standard components which include: Valve body, plunger seal, O-rings, armature guide tube, plunger, spring, shading ring, stopper, flange, bonnet, coil, flat seal, cable plug and locknut. Miniature solenoid valves are also available which eliminate the need for O rings and backup rings. Solenoid valve connectors are used to connect solenoid valves and pressure switches.
Solenoid valves are most commonly used to control elements in fluidics. This means dependability and long service life are important factors when choosing your valves. While selecting a solenoid valve there are various other things you should consider such as:
- The type of control, pressure or flow.
- The actuation method, electrical, hydraulic, pneumatic or a combination of any of these.
- Un-powered state, configuration of the valve when there is no power which may be: normally open, normally closed, float or tandem center.
- The valve flow co-efficient (which is the amount of water in US gallons at 60 degrees F that flows through a standard opening in minutes).
- The valve size and size of the passage.
- The pressure rating, which is the maximum safe pressure that the valve can withstand.
- The number of inlets that are available.
- The number of setting positions and connection details that include threading size, compression fitting, details of flange, bolts and sockets used.