Pressurepac Series Miniaturized Air Driven Hydraulic Power Units • OM-7S
4
Performance
HIGH FLOW FROM BLADDER
When control valve is actuated to the ‘run’ position, full air pressure is applied to the inside of the bladder.
The bladder expands to force oil out through the pump and momentarily through the release valve at up
to 7 gpm (depending on viscosity and initial resistance of the total system during approach).
HIGH PRESSURE FROM PUMP
(up to 15,000 PSI depending on Model)
Pump output will vary with system resistance (after rapid approach from bladder output). Nominal
hydraulic power output from pump is about ½ HP with an air or nitrogen drive of 125 PSI; 1/3 HP with 85
PSI drive. Detailed performance charts on each model ratio are in the current catalog.
Installation
General
Pressurepac Power Unit may be mounted in any position after the tank has been filled.
Air System
It is not necessary or desirable to use an air line lubricator. The air spool, air drive barrel and air piston o-
ring have been prelubricated at the factory. However, an air line filter with a minimum of ¼” NPT port size
is suggested. Also, review air system upstream and eliminate any restrictions to provide ¼” minimum
inside diameter.
Hydraulic System
CAUTION: Do not loosen hydraulic outlet fitting on pump to facilitate make-up of piping connections. This
fitting must be tight to avoid leakage or damage. (Note torque required on assembly drawing.) Output
pipe, tube or hose size should be selected to provide desired retracting speed for single acting tool(s)
being actuated.
FLUIDS
Petroleum base or silicone base hydraulic oils. Light viscosities are recommended for optimum
performance.
FILLING OR ADDING FLUID
Follow procedure outlined on assembly drawing for Pressurepac model purchased.
NOTE: Be patient during siphoning action of bladder.
Actuate air control valve. Bladder will expand, forcing air out through tool hose into oil supply tank. Shift to
retract position. Bladder will siphon oil into Pressurepac through release valve. Repeat until air bubbles
are no longer expelled into oil supply tank.
Operation
Note that the model number includes its nominal area ration as a suffix. The pump will cycle rapidly
initially and as it approaches an output pressure equal to the ratio times the air drive pressure, it will slow
down and finally “stall”. Air pressure regulators (on models so equipped) have 5 PSI or more differential
between “flow” and “no flow” air pressures. Where it is necessary to pump an appreciable volume near
the “stall” pressure, a high flow precision type air regulator should be used, or maximum pump pressure
should be controlled by some other device such as the relief valve, pressure switch, or pressure operated
shut-off valve, such as a Haskel air pilot switch.
