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How does a solenoid valve work?

A solenoid is an electromagnetic switch that consists of a coil of wire with a ferrous metal core, often made out of iron.

When a current passes through the coil, a magnetic field is induced in a predetermined direction, which in turn moves the core in a piston action.

The movement of the core, or piston, can drive a desirable result each time the solenoid switch is activated, but would ordinarily need to be reset manually to its starting position.

It’s normal for a solenoid to contain a spring or equivalent mechanism, so that once the electric current is switched off, the piston core returns to its default position.

An alternative, if the orientation of the solenoid is known in advance, is to allow gravity to pull the piston back down, after an induced magnetic field deflects it vertically upwards.

Controlling fluids with solenoid valves

In a solenoid valve specifically, the movement of the piston is used to open or close one or more valves.

This may be achieved by having a liquid contained under pressure behind the piston, which is able to flow freely through the solenoid once the metallic core is moved by the induced field.

Solenoid valves can be quite complex, with multiple inputs and outputs, which in turn can be mixed together as they flow through the valve.

Alternatively, a single input, single output valve can be only partially activated, so that the dose or flow rate of the fluid in the valve is controlled.

Benefits of solenoid valves

Solenoid valves offer a range of benefits, including:

  • Overall cost efficiency, from low initial purchase cost to improved efficiency
  • Fast response time for precise control of flow valves
  • Very low power consumption further reduces running costs

For all these reasons and more, solenoid valves have become a very popular option across all kinds of industrial applications.

If you’d like to know more, please read our Solenoid Valves FAQs from the start of this year.

Or if you’re interested in placing an order and need some assistance choosing the correct solenoid valves for your project, please get in touch directly and we will be happy to help as much as we can.