Thursday, March 12, 2020

Solenoid Valve


Solenoid valves are simple devices to close, discharge, dispense, distribute, and mix fluids. They are an important component in most pneumatic systems. These valves are simple and inexpensive, but choosing the valve that best suits your needs can be confusing.



To fully understand how this solenoid valves work, it is best to first understand what a solenoid is. Solenoids are coils that are tightly wound in a spiral. This coil encloses a metal core that generates an electromagnet when powered. The higher the electric current, the stronger the electromagnet. The difference between the beauty of electromagnets and ordinary magnets is that they can be turned on and off. Therefore, solenoids work in systems that block, block, or activate other mechanisms.



So if the solenoid is part of the valve, it triggers the opening and closing of the valve. The force generated by the electromagnet pushes or raises the piston and, as a result, stops the flow of air, gas, or liquid.



Some advantages of using solenoid valves are:
  •             Fast and safe conversion
  •             High reliability
  •             Long life
  •             Excellent intermediate compatibility of used materials.
  •             Low control power
  •             Compact design

Direct Acting v. Pilot Operated Solenoid Valves

Of course, solenoid valves are available in various types depending on flow, type of fluid, and operation.

The two main types of solenoid valves are direct operated and pilot operated valves. The direct acting valve uses an electromagnet power supply to open and close the valve. On the other hand, the pilot operated valve uses electromagnetic force combined with the air / liquid / gas pressure that flows when opening and closing the valve.

Choosing what to use mainly depends on the flow rate of the fluid used.


Direct acting valves depend only on the electromagnetic force of the solenoid, making this type of valve best suited for smaller flow rates. One of the benefits of using these is that you only need to use energy when opening the valve. When the valve is open, this valve can remain open even when operating at low power.

If you need something that can handle higher flows, a pilot operated valve does the trick. This valve uses the combined force of the electromagnet and the fluid itself to open and close the valve. You may be wondering how this is possible.


Pilot operated valves require less power to operate, but to remain open they must maintain maximum power. As a result, it operates at a slower speed than a direct acting valve. However, this does not prevent it from becoming the most widely used type of solenoid valve.

Solenoid valve variations

There are a few more variations on the two main types of solenoid valves. This includes 2-way valves, 3-way valves, and 4-way valves.

Indicates the number of ports on the solenoid valve. In the basic 2-way solenoid valve, 2 ports are used alternately to allow and shut off flow. On the 3-way valve, 2 ports are used to allow and shut off flow, and the third port is used to relieve pressure. The 4-way valve uses half of the port to provide pressure, and the other port provides exhaust pressure. Four-way valves are commonly used with double acting cylinders or actuators.


Another option is whether the valve should be in a "normally closed" or "normally open" state. "Normally closed" valves are the most common; as they remain closed until the power supply is opened. A "normally open" valve will remain open until some kind of current is applied to close the valve.

When deciding on a solenoid valve, one thing to consider is the material the valve is made of. The most common valve materials are brass, stainless steel, aluminum, and plastic. It is necessary to consider the type of fluid that will be used for the operation and what type of material to choose for the seal. This will make the valve work properly.