Skip to content


Hydraulic Power Unit – Light Duty


This Hydraulic Power Unit is designed to provide a source of hydraulic power for aircraft hydraulic system testing.  The system has two independently controlled systems.  The unit can provide up to 15 gpm at 3000 psi or 7.3 gpm at 5000 psi per system with open or closed loop operation.  This unit can also combine both individual systems into a single system that provides up to 27.5 gpm at 3000 psi.  The unit is equipped with an operator interface touch screen and PLC controls.  The instrumentation includes main pressure, boost pressure, return pressure, flow, temperature, water content (ppm), filter indication, fill/drain aircraft reservoir and return pressure control.  The unit is completely self-contained.

Fluid cooling is accomplished through air-to-oil heat exchanger and direct-driven fan.  The boost pumps supply a sufficient amount of fluid to the main pumps.  The main pump is a pressure compensated, variable volume piston pump with load sense.  A flow meter in the main pressure line to the aircraft assures accurate flow readings.  A bypass valve permits setting the main pump flow to a known value before supplying flow to the aircraft.  The same valve also permits the operator to reduce system pressure quickly in case of emergency.

The power unit is capable of open or closed-loop operation.  Panel mounted return bypass valve is used to bleed off return pressure when operating in the aircraft reservoir (closed-loop operation) mode.  A return pressure control system permits the operator to control the aircraft reservoir fluid level when operating in the hydraulic power unit reservoir (open-loop operation) mode.  A thermal relief valve in the return system protects the return system from over-pressurization during shutdown due to thermal expansion of fluid.  Water content measured in parts per million (PPM) is monitored in the reservoir and each return line.  System warns if level exceeds a specified limit.

The power unit is equipped with a remote control touch screen allowing the operator to have full system control.  The remote control allows the operator to be close to the aircraft during testing or seated in the cockpit.

The power unit is equipped with a purifying system that cycles the reservoir fluid continuous while the unit is powered.  The system has a particle and water removal filter.  This is the fluid that is used for filling the aircraft reservoir when selected.

The safety systems include proportional maximum pressure relief, low boost pressure shutdown, over-temp, low/high fluid warnings/shutdown.  Unit is also equipped with a DRT system that minimizes fluid aeration and foaming.