[Rick TYler]

Originally Posted by dtengineering

So consider the situation where you have a cylinder pressurized to 60psi. Hook it up as normal, but then run the vent from the solenoid valve to another solenoid valve. This second solenoid valve can output to either a regulator set to 30psi feeding a storage tank on a low pressure side of the system, or to atmosphere.

Or you could just vent the exhaust side of your solenoid through a small-diameter aperture which blows on a little windmill attached to your driveshaft...