How does an air solenoid valve work?

A solenoid valve uses electromagnetic energy to open and close the valve. In an air solenoid valve, the closed valve uses a rod to block air from moving from one part of a system into another. The rod must be made from a ferrous metal, such as iron or an iron alloy like steel. To open the valve, an electrical current passes through the solenoid coil, generating a magnetic field which pulls the rod, allowing air to flow through the valve. Air solenoid valves can be manufactured to be normally open or normally closed, with the current moving the rod.