Solenoid Valves - A Beginners Guide

By Terry McDonald on 17th February, 2017

What Is A Solenoid Valve & How Do They Work?

So what is a solenoid valve and how do they work?

Simply, a solenoid valve is an electromechanically operated valve. So there you go, end of discussion. Not quite as simple as that, let me try to explain more.

Solenoid Valves

Solenoid Valves

A solenoid valve is an electromechanical valve which is normally used for the fluid control of water, air, oil or gas. They are made up of two components:

i) the solenoid (essentially consisting of a coil, core, core tube, shading coil and spring)

ii) the valve (the body containing orifices in which the disc, diaphragm or piston is positioned).

Now if you really are a beginner reading this, I have no doubt I have already used some terminology that is unfamiliar, so here is my explanation.

The solenoid is a coil which has a current passed through it when it is energised. The current causes a magnetic field which moves the core up or down. This movement is what essentially opens or closes the solenoid valve body. If the valve is opened, fluid is allowed to pass. If the valve is closed, fluid will be blocked.

Now for some terminology explanations:-

Solenoid Coil – the coil is the electrical part and consists of a spool wound with insulated copper wire. A magnetic field is created when the coil is energised.
Core – a soft magnetic plugnut which is moved by magnetic forces.
Core Spring – the spring is used to keep the core in its fixed position.
Disc, Valve disc – the sealing material on the disc holder which shuts the seat orifice.
Disc Holder – part of the valve which is actuated by the core.
Pilot Orifice – this is located in the centre of the diaphragm and is opened or closed by the core.
Seating or Valve Seat – this is a specially formed boarder of the valve seat.

T&D work in partnership with ASCO who are at the forefront of solenoid valve technology. Solenoid valves are available in many shapes and sizes. In fact there are over 500,000 within the standard range. 2 way and 3 way solenoid valves are fairly common and are used in almost all industries.