working principle
　　The feed valve is opened by energizing the motor or the electromagnet, and is turned off by the return spring after the power is turned off, thereby achieving the purpose of controlling the material flow.

　　Features
　　1. Compact structure and easy installation, it can be fixed directly in the material pipe by means of screws.
　　2. Simple design and reliable control
　　3. Made of stainless steel for durability
　　4. Wide applicability, good quality and low price.