Solenoid Valves Offer ‘Brains’ for Gas & Liquid Flow Control
by Rebekah Fuller, Editor for IQS
Equipping a hydraulic or pneumatic valve with a solenoid coil adds a higher level of control to air or fluid flow regulation. Unlike regular valves that rely on changes in gas or fluid pressure to open or close, solenoid valves are operated electromechanically with a magnetized solenoid coil that responds to targeted electrical charges for precise flow control. Because of the ability to be controlled remotely and cued by sensors or hysteresis (device memory), the solenoid valve is an intelligent gadget.
The solenoid coil is an actual coil of wire that is the medium for the electric current. In its simplest form, a solenoid valve is operated like a typical on/off switch. By running electrical current through a solenoid, the valve is turned “on”. Simply stop the current and the valve is shut “off”. While the valve is “on”, the solenoid coil does the job of converting electrical energy into mechanical energy, thus opening or closing the valve mechanisms. Two-port solenoid valves consist of “on” or “off” flow; however, three-port ones switch flow between two outlets, and manifolds can be made of a number of solenoid valves.
The advantages of these “smart” solenoid valves include fast, safe flow switching, high reliability and repeatability, a long life, low operational power requirement and compactness. Some companies specialize in solenoids themselves, as they are actuators capable of linear motion when given energy. Solenoids aren’t simply great valve operators; their applications range from button-pushing to robotics. Certain valve manufacturers offer solenoid valves as part of their product lines. Consult a solenoid valve manufacturer to receive recommendations for your flow control application; see if a solenoid valve configuration, such as plunger-type actuator, pivoted-armature actuator or rocker actuator, is appropriate.
The majority of solenoid valves are air solenoids utilized in pneumatic systems. These air valves are used to control cylinders or large industrial valves, such as in combustion systems or dust collectors. Another common use for solenoid valves is in automatic sprinkler systems used for irrigation, and just a few home appliances that operate with solenoid water valves are ice cube makers, refrigerators and dishwashers. An interesting note – a solenoid valve use that has gained popularity is in the paintball industry to assist a larger valve that controls the compressed air propellant.