Solenoid valve – What do you want to know about this type?

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Solenoid valve – What do you want to know about this type?

To control the fluid flow that I am working on, my main task is to improve the system how to it performs faster and more reliably than the old valve. It is important to have a good life expectancy. In this article I will share my insights on the solenoid valve, hopefully, it will be useful for my colleagues.

Solenoid valves are one of the most popular valves, common valves at now. Therefore its application is extremely broad: in civil or industrial, etc.


  1. Definition

Solenoid valves are an electromechanical device used to control fluid or gas flow. Solenoid valves controlled by 220V or 24V currents are operated via a coil. When the coil is electrically powered, a magnetic field is created that creates the force acting on the plunger inside the coils to cause the piston to move. Depending on the design of the valve, the piston acts either to open or close the valve. When the current is disconnected from the windings, the valves return to their original state.

  1. The structure of the solenoid valve

See below, you can realize that

1) Valve body: bronze or stainless steel, plastic.

2) Fluid: liquid (water, oil) or gas (compressed gas, gas, etc.)

3) Empty axis pipe – No flow through.

4) Coil Casing (Used to protect the coil)

5) Coil coil (Coil magnet will generate the suction force)

6) Wires (can use voltage 220V, 24V, 110V)

7) An axis valve sealed (normal state spring 8 will impact sealed, help the valve in the closed state).

8) Springs

9) Fluid leakage through when valve opening

Basically, a solenoid valve will be constructed as above. However due to some special technical requirements. Such as working environment, temperature, pressure, flow through, materials. That some electromagnetic valves will be specially designed will be different than the above drawing.

There are two basic types of solenoid valves, there are: the normally closed solenoid valve and the normally open solenoid valve. In this article, we will briefly share with you the principle of operation of:

Normally open solenoid valve (NO)

  • Original, the valve is always closed when the valve is not energized. While, the flow of fluid on the pipe meets the valve will stop moving because the valve is closed.
  • Next we supply power to the valve (Can use 220V alternating voltage or 24V voltage). When the magnetic coil generates a certain suction force, the suction force absorbs the spindle valve. And the sealing gasket to the top.
  • With the suction power of the magnetic coil to spring the thrust, the disc and Gioăng (Rubber seals) sealed to the valve body will form a certain gap. And then the fluid will leak through the valve and when the spring is compressed to the maximum. The electromagnetic valve will open completely and create the valve phenomenon open valves.
  • When the power supply is unoccupied, the springs will naturally expand, compress the discs. And Gioăng seals to the valve body and return to its original closed state.
  • So when we need to open the valve, we supply electricity. And when we need to close the valve we stop supplying electricity for it. Because of the magnetic coil is almost instantaneous. So the solenoid valves usually open and close very fast, it can be called “open immediately”.

From here we can see that the principle of operation of the normally open solenoid valve (NO) will be similar to the normally closed electromagnetic valve.

  1. Application of solenoid valve and its importance

With the continuous development of technology. As well as the automation of production in general and consumption in particular. The opening and closing of the piping equipment is also automatic and becomes urgent. Solenoid valves have been studied and produced for a long time, now the valve is more popular in Vietnam market.

To meet the increasing demand of the market, valve companies in Vietnam have been importing a variety of valves in time to meet the needs of diverse customers.

  1. Classification of solenoid valves

  • Solenoid valves are classified according to the following factors
  • Sort by function, there are two types of solenoid valves: solenoid valve is normal open (NO) and solenoid valves are usually closed (CO).
  • Sort by valve material: copper solenoid valves, plastic solenoid valves, stainless steel solenoid valves.
  • Sort by voltage: solenoid valve 220V, solenoid valve 24V, and solenoid valves 110V.
  • Sort by Installation type: solenoid valves, solenoid valve, solenoid valve, flange solenoid valves.
  • Sort by origin: Korean solenoid valves, solenoid valve Taiwan, solenoid valve Japan, solenoid valve Italy.
  • Sort by brand: UniD solenoid valve, TPC solenoid valves, Round Star solenoid valves, SMC solenoid valve, solenoid valves STNC, solenoid valves CKD, etc.

We will stop at here today, in the next post may be I will find out more about pros and cons of Solenoid valve. Wait me, OK! Thanh you!