Accumulators: Hydraulic energy storage

Hydraulic energy storage By Chris Grosenick (abive right) Accumulators provide backup power for brakes, landing gear, emergency applications, and APU starting. The average pneumatic charge in an accumulator is 1,000- to 2,000-psi...

Safety issues
Accumulators store large amounts of pressurized gas and fluid and are hazardous to the untrained and uninformed. The average pneumatic charge in an accumulator is 1,000- to 2,000-psi pressure. This is more than enough pressure to puncture the skin and cause severe health problems - even death. Another hazard is the fully charged accumulator. With 3,000 psi or more fluid pressure stored, a small leak can cut through clothing and skin like a razor. Never use your bare hand to check for any hydraulic or pneumatic leaks, rely on sight and hearing to locate leaks. Generally, large pneumatic leaks are immediately evident using soapy water, and hydraulic leaks under pressure will create a mist that looks like smoke. Always wear eye protection when servicing any pneumatic component. Sometimes gauges, plumbing, and components give way when being re-pressurized, and an unexpected air release from the servicing equipment could damage your eyes.

Respect the energy stored in these devices and the hazards they impose, and always consult the maintenance manual for aircraft specific practices and cautions when working on pneumatic and hydraulic systems.

Additional ReSources
Army TM 55-1520-240-23-2, CH-47D Maintenance Manual
Boeing 757 Maintenance Manual
F-15 Hydraulic Systems, The Boeing Company and Chris Grosenick

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