@jauhar123 | Posted 12 Aug. 2019
A spring return valve operates on pressure from one direction and needs it released from other direction. When there is no pressure provided for this system the valve defaults to same location that is triggered by the spring.
A non spring return also operates on pressure but due to absence of spring the valve does not returns to the original position, it stays at the same position where it was when the pressure stopped.
There are multiple types of Pneumatic Valve: