Solenoid Valves

What are Solenoid Valves

As the name indicates, valves are gateways for controlling the flow of an object. In case of solenoid valves, the object is either liquid or gaseous in nature. The solenoid transmits the electric current through which the valve is controlled.

Due to the safety offered by solenoid valves as well as the ease of use, they are amongst the commonest elements used in fluidics. While the plunger-type actuator is the most widely used type of solenoid valves, others like pivoted-armature actuators and rocker actuators are also in vogue.

The basic design of solenoid valves comes with either two or three ports. In case of a two port valve, opening and shutting down the flow of the fluid is the only task of the valve. Solenoid valves coming with three ports are used for switching the flow between two ports.

Classification and Working Principle of Solenoid Valves

On the basis of designs, solenoid valves are divided into several categories. The most basic one way valves are classified into three major types based on the number of valves used, type of power supplied and the number of positions and ways.

Solenoid valves consist of two major parts- the solenoid and the valve. Electrical energy supplied to the solenoid is transformed into mechanical energy which is used for opening or closing the valve. Depending on whether the valve is direct acting or diaphragm piloted, the amount of fluid passing through the valve varies.

The basic principle behind the proper functioning of solenoid valves is the maintenance of pressure difference between the input and the output. Input pressure always has to exceed the output pressure for solenoid valves to function. In case of the input pressure falling below the output pressure, the valve will open automatically.

The power consumed by solenoid valves depends on the position of the solenoid with respect to the valve.

Application of Solenoid Valves

Though solenoid valves are most widely used in fluid control, it is also used for pharmacology experiments for patch-clamps. In more traditional usage, it is used in fluid power pneumatic and hydraulic systems.

Washing machines and dishwashers also utilize solenoid valves for controlling the flow of water into the appliance. Dental chairs also make use of solenoids for the purpose of controlling air flow.
Besides these, automatic irrigation sprinkler and paintball industries are two other areas of application of solenoid valves.