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Hydraulic Power Unit – Light Duty

This Hydraulic Power Unit is designed to provide a source of hydraulic power for aircraft hydraulic system testing.  The unit has 3 independent systems that can provide up to 10gpm (system 1), 10gpm (system 2) and 7gpm (system 3) at 3000 psig with open or closed loop operation.  The unit’s instrumentation includes a PLC touch screen that monitors pressures, flow, temperature, valve positions, filter indicators and water content in the hydraulic fluid.  The unit is completely self-contained.

Fluid cooling is accomplished through air-to-oil heat exchanger and electric-driven fan.  The boost pump supplies a sufficient supply of fluid to the main pump.  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.  A 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 regulator 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 system from over-pressurization at shutdown due to thermal expansion of fluid.

The power unit is equipped with a remote control allowing the operator to control main system pressure, direct pressurized fluid to the aircraft, fill or drain aircraft reservoir fluid level and shut the unit off in case of an emergency condition.  This control allows the operator to be close to the aircraft during testing or seated in the cockpit.  The remote control also has an independent system with the capability to fill or drain accumulators, brake system, dampers or other low pressure hydraulic devices.

The power unit includes on the screen indicators to warn the operator of a required filter change.  Safety systems include maximum pressure relief, low boost pressure shutdown, water contamination sensor, over-temp and low fluid warnings.