1. How does a Solenoid Valve Works？

I. Solenoid Valves Classified by Control Mode

1. Normally Closed Type: The air circuit is closed when the coil is de-energized.

2. Normally Open Type: The air circuit is open when the coil is de-energized.

3. Self-Latching Type: When the coil is energized, the solenoid valve opens and remains open after de-energization; when the coil is energized, the solenoid valve closes and remains closed after de-energization.

II. Solenoid Valves Classified by Action Mode

Direct-Acting Type

Components:

1. Coil

2. Magnetic Isolation Tube

3. Valve Core

4. Spring

5. Sealing Element

6. Valve Body

Pilot Diaphragm Type

Components:

1. Coil

2. Magnetic Isolation Tube

3. Valve Core

4. Spring

5. Seal

6. Valve Body

7. Diaphragm

8. Spring

9. Pilot Hole

10. Valve Cover

Step-by-Step Direct-Acting Type

It adopts a combined principle of direct-acting and pilot-operated.

• When there is no pressure difference between the inlet and outlet: After energization, the electromagnetic force directly lifts the pilot small valve and the main valve closing part up in sequence, and the valve opens.

• When the start-up pressure difference is reached between the inlet and outlet: After energization, the electromagnetic force acts on the pilot small valve, causing the pressure in the lower cavity of the main valve to rise and the pressure in the upper cavity to drop. The main valve is then pushed open by virtue of this pressure difference.

• When de-energized: The pilot valve pushes the closing part downward by spring force or medium pressure, closing the valve.

2/2 Way Solenoid Valve

The valve body has one inlet and one outlet connected to the pipeline. This solenoid valve is a one-way valve, which is used for one-in and one-out operation in the direction indicated by the arrow.

3/3 Way Solenoid Valve

The valve body has 3 ports connected to the pipeline with two holes, and is applicable for three control modes:

• Normally Closed Type: The pressure port is closed when de-energized, and the exhaust port is connected to the cylinder port; the pressure port is connected to the cylinder port and the exhaust port is closed when energized.

• Normally Open Type: The pressure port is connected to the cylinder port and the exhaust port is closed when the valve is de-energized; the pressure port is closed and the cylinder port is connected to the exhaust port when the valve is energized.

• Universal Type: The valve can be connected to either the normally closed or normally open position as required.