What are the structure and characteristics of the direct-acting solenoid valve?

Direct-acting solenoid valve is mainly composed of solenoid coil, valve body, valve cover, moving iron core, spring and other components.

Structural characteristics of direct-acting solenoid valve
The direct-acting solenoid valve adopts a stainless steel spool structure, which greatly improves the anti-corrosion ability of the valve and overcomes the shortcomings of easy jamming. The corresponding material is used to seal the media to improve the sealing performance of the valve and extend the service life of the solenoid valve. 

The working principle of direct acting solenoid valve
For a normally closed solenoid valve, when the solenoid coil is energized, the valve core is attracted and the valve opens; when the solenoid coil is de-energized, the valve core falls due to its own weight and the valve core spring, and the valve closes.
For a normally open solenoid valve, when the solenoid is energized, the spool is attracted and the valve is closed; when the solenoid is de-energized, the spool is reset by the spring and the valve opens.
Principle with signal feedback: When the solenoid valve is opened, the common line is connected with the open signal line, but not with the closed signal line; when the solenoid valve is closed, the common line is connected with the closed signal line, but not with the open signal The line is connected.
　　
Question: What is the difference between direct-acting solenoid valve and pilot solenoid valve in use?
Answer: The direct-acting solenoid valve is energized by the solenoid coil to directly open the main valve port, the medium is circulated, and the zero-pressure start is easy. Compared with the pilot solenoid valve, the direct-acting solenoid valve starts faster.
When the coil of the pilot solenoid valve is energized, the electromagnet core is attracted, the pressure relief hole opens, the main piston is pushed by the medium pressure, the main valve port opens, and the medium circulates.
The difference is that the direct-acting type is suitable for zero-pressure small-diameter pipelines, and the pilot type is suitable for high-pressure large-diameter pipelines.