How do solenoid valves work

This valve is similar to other solenoid valves in that it either stops or starts the flow of the liquid, but it differs in the process it uses to do this.

When a normally closed solenoid valve is not powered, the plunger is down, effectively sealing the valve and preventing the flow of liquid or gas.

Once the normally closed solenoid valve is powered or energized, the magnetic field causes the plunger to rise. This unseals the valve and allows the flow of liquid or fluid to pass through. A 2-way, normally closed, solenoid valve has 2 pipe connections, an inlet called the cavity port and an outlet called the body orifice port. When the valve is energized the plunger opens allowing media to flow through the valve in the cavity port and out the body orifice port.

This magnetic field is what controls the valve. We have two types of valves, the normally open and the normally closed types. Lets look at the normally closed type first. Inside the valve we have the armature. Inside the cylinder of the armature is the plunger and spring. The spring pushes the plunger down in a normally closed type valve. Because the plunger is pushed by the spring, it will sit in the down position to close the valve indefinitely. But, if the coil receives an electrical current then it will generate an electromagnetic field and this magnetic field passes through the plunger and will cause it to move upwards against the spring therefore opening the valve.

See the YouTube video for detailed animation. At the centre of the coil the magnetic filed lines are the most compact and therefore the strongest.

This why we place the plunger in the centre. Once the electrical current is stopped then the magnetic field disappears and the spring will force the plunger down again to close the valve. With normally open valves we again have the coil sit around the armature but this time the spring pushes the plunger in the upwards position so that the valve is always open unless the solenoid coil is powered. If we then pass a current through the coil it again creates an electromagnetic field but this time the field pushes the plunger instead of pulling it.

When the plunger is pushes it will close the valve and stop the flow of fluid in the system. When the electrical current is stopped the spring will then force the plunger back into the upward position and open the valve again. This article solves a lot of my problems.

Great article! Coming off the capillary tubes is a solenoid valve and solenoid coil. Really informative article Paul! Solenoid valves are based on incredible engineering. A well-designed one can be used in ESD applications, hydrogen systems and high pressure cryogenics.

I have gone through your blog, it gives very good information about solenoid valves. Here you explained about two types of solenoid valves i. Can you tell me which one is more efficient in the manufacturing industry? I appreciate you helping me learn about how solenoid valves work and how we use them in our daily lives. Very informative article about solenoid valves.

They are also an extremely efficient way of controlling flow, as they require very little wiring, expense and effort compared to other valves. It is also very important that the correct voltage is applied to these valves. At Fluid Controls, we supply a wide range of solenoid valves, including Maxseal solenoid operated valves. Well known for performing immensely well in extreme and hazardous environments, Maxseal solenoid valves have been installed in plants all over the world for many years.

For more information on how solenoid valves work, or to discuss our full range of solenoid valves, get in touch today on or via email at fluid fluidcontrols. Email: fluid fluidcontrols.

Follow us. Keyword s. How does a solenoid valve work? An electrical current then runs through the coil, creating a magnetic field. The magnetic field then places force on the iron plunger, resulting in the plunger being pulled towards the centre of the coil opening the orifice. This is what in turn controls the flow, allowing for the shut-off or release of media.

There are three main solenoid valve technologies: direct acting, in-direct acting and forced-lift piston type. Each of these solenoid valves work in slightly different ways and are suited to different applications.