How Solenoid Valves Work？

1. What is a Solenoid Valve？

A solenoid valve is an automatic basic component used to control fluid (usually compressed air or liquid). It is a valve that relies on the electromagnetic force generated by the power supply coil to drive the movable iron core to open and close the valve disc.

2. How Do Solenoid Valves Work？

（1）solenoid Switch Valve

By energizing/de-energizing the solenoid coil to control the opening/closing of the line or to change the fluid flow direction.

（2）solenoid Control Valve

Change the fluid flow or fluid pressure in the pipeline controlled by parameters such as solenoid voltage/current.

3. Classification of Solenoid Valves

The solenoid valve can be divided into direct-acting solenoid valves, step-by-step direct-acting solenoid valves and pilot-operated solenoid valves in principle.

The working principle of the direct-acting solenoid valve: when the power is turned on, the solenoid coil generates an electromagnetic force to lift the closing member from the valve seat, and the valve opens; when the power is off, the electromagnetic force disappears, the spring presses the closing member on the valve seat, and the valve closes.

The working principle of the step-by-step direct-acting solenoid valve: when there is no pressure difference between the inlet and the outlet, after the power is turned on, the electromagnetic force directly lifts the pilot valve and the main valve closing piece upward in turn, and the valve opens. When the inlet and outlet reach the starting pressure difference after the power is turned on, the electromagnetic force pilots the small valve, the pressure in the lower chamber of the main valve rises, and the pressure in the upper chamber drops, so as to use the pressure difference to push the main valve upward; when the power is turned off, the pilot valve uses a spring The force or medium pressure pushes the closing member, moving downward, causing the valve to close.

The working principle of the pilot solenoid valve: when the power is turned on, the electromagnetic force opens the pilot hole, the pressure in the upper chamber drops rapidly, and a pressure difference between the upper and lower parts is formed around the closing part, the fluid pressure pushes the closing part to move upward, and the valve opens; when the power is turned off , the spring force closes the pilot hole, the inlet pressure quickly forms a pressure difference around the valve closing member through the bypass hole, and the fluid pressure pushes the closing member to move down to close the valve.

4. Features of Solenoid Valve

The characteristics of the solenoid valve are rapid action, simple structure, easy operation, safe use, limited adjustment accuracy, and limited applicable medium.

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5. Application of Solenoid Valve

A solenoid valve is industrial equipment controlled by electromagnetic, which is used to adjust the direction, flow, speed, and other parameters of the medium in the industrial control system. The solenoid valve is mainly used to automatically cut off, connect or switch the flow direction of the fluid.

For example, in the pneumatic system, the function of the solenoid valve is to adjust the various states of the compressed air in the control system according to the control requirements. The compressed air mainly works by acting on the piston or the blade.

With the continuous advancement of technology, the combination of solenoid valve technology and control technology, computer technology, and electronic technology has been able to carry out a variety of complex controls, which can be used in food, medicine, electronics and other industries. For example, solenoid valves can be applied in the field of intelligent control and in wireless control technology. It is precise because the solenoid valve can be controlled electromagnetically that it can interface well with various electronic systems, which is one of the main reasons why it is widely used.

Due to the characteristics of simplicity, convenience and safety, and with the advancement of technology, the application of solenoid valves is becoming more and more extensive. Regarding the working principle of the solenoid valve, I will introduce it to you here, I hope it can be helpful to you.