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SL-700

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 one system that can provide up to 30-50gpm (depending on which model ordered) at 3000 psig with open or closed loop operation.  The unit’s instrumentation includes main pressure, return pressure, flow, temperature, fluid water content and filter indication on the HMI screen.  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.  The hydraulic system is controlled by a PLC system with user interface to control flow and pressure.  An optional 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 system from over-pressurization during shutdown due to thermal expansion of fluid.  Water content, measured in percent of saturation (%S), is monitored in the reservoir and return line.  System warns if level exceeds a specified limit.

Operator has control of open/closed system operation, flow, main system pressure, fill or drain aircraft reservoir fluid level and shut unit off in case of an emergency condition. 

The power unit is equipped with a purifying system that cycles the reservoir fluid continuous while the unit is powered.  The system removes particles, moisture and dissolved gases from the oil system.  This is the same fluid that is used for filling the aircraft reservoir when selected.

The power unit includes filter electrical indication 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.  Unit is also equipped with a DRT system that minimizes fluid aeration and foaming.