Ed, maybe I miss applied a term, between CRS and not being an engineer I do that a LOT--
what I was refering to is a push button switch/valve that is in a pressured line from the supply to the actuator cyl. When you push it down it lets the pressure pass through to the actuator cyl.; but when you release the button it stops the air from passing the switch/valve and there would then be no pressure on the cyl.,