MGA Controls is a leading supplier of solenoid valves for the Process Industry. In this article, we give you an in-depth overview of what a solenoid valve is and how they function.

What is a solenoid valve?

A solenoid valve is an electromechanically operated valve. The valve is controlled by an electric current through a solenoid. In the case of a two-port valve the flow is switched on or off. With three-port valves the outflow is switched between the two outlet ports. While multiple solenoid valves can be placed together on a manifold.

What is a solenoid valve

Solenoid valves are the most frequently used control elements in fluidics. Their tasks are to shut off, release, dose, distribute or mix fluids and 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.

How does a solenoid valve work?

Solenoid valves operate using an electromagnetic solenoid coil to change the state of a valve from open to closed, or vice-versa. If the solenoid valve is ‘normally closed’, when the coil is energized, the valve gets lifted open by the electromagnetic force produced by the coil.

Two forces counter one another in the valve: the spring force and the force by a proportional solenoid. Without a power supply the spring pushes the plunger directly on to the valve seat, which keeps the valve outlet closed. When power is supplied to the solenoid, the plunger rises, the valve opens and the fluid passes through.

Solenoid valve types

There are many valve design variations. A 2-way valve, for example, has two ports. If the valve is open, then the two ports are connected and fluid may flow between the ports. If the valve is closed, then ports are isolated. If the valve is open when the solenoid is not energised, then the valve is classed as normally open. Similarly, if the valve is closed when the solenoid is not energised, then the valve is said to be normally closed.

There are also 3-way valves that have three ports. These connect one port to either of the two other ports that are typically a supply port and an exhaust port. Solenoid valves are also characterised by how they operate. A small solenoid can generate a limited force but, if that force is sufficient to open and close the valve, then a direct acting solenoid valve is applicable.

Solenoid Valves from MGA Controls

MGA Controls’ experienced and knowledgeable team can talk you through all your solenoid valve requirements. With more than 30 years of supplying premium solenoid valve products to the Process Industry, as well an impressive range of solenoid valve brands (including Norgren, Bürkert and ASCO), we guarantee to match you and your application to the best solenoid valve solution.

Speak to one of our sales advisers today on +44 (0) 1704 898980. Alternatively, email us at