Solenoid valve P is the inlet, A is the outlet, and R is exhuast.
Quick exhaust valve, P is the inlet, A is the outlet, R is the exhuast
This connection is to keep the pneumatic pinch valve normally closed
The valve opening speed is related to the elasticity of the hose and the exhaust speed in the valve cavity.
A quick exhaust valve can be selected to increase the valve opening speed.