Hydronic Air Driven Pumps & Intensifiers
P720 Installation, Use and Maintenance Booklet 08-21-09
Page 5
Air Operated Pressure Release Valve
This mechanism is intended for use in systems where no directional control valves are
used. Pressurized oil from the system will be released internally back to tank when pilot
air pressure is applied to the 1/8” NPT connection shown here as H.
Commonly, a small pneumatic valve will be used to direct regulated air pressure either
to the pump or to the pressure release valve. In this way, the pump is started with the
system intact and stopped with the oil pressure vented safely to tank. Varieties of
pneumatic valve may be used including solenoid and lever, allowing the power unit to
be situated away from the operator.
The adjustment C1 may be needed when the pilot air pressure is low or if the required
oil pressure is at the highest level. Adjusting the screw inward will hold the valve shut with
more force but will also require more pilot air pressure to release it.