Hydraulic and Pneumatic Power Systems Flashcards
What are three types of hydraulic fluids ?
Vegetable, Mineral , Phosphate Esters
Which color mineral base and phosphate ester hydraulic fluids have ?
Mineral - Red / Phosphate ester - Light Purple
What happens to plastic resins, vinyl compositions, lacquers, and oil base paints if exposed to a phosphate ester base hydraulic fluid such as skydrol ?
Damaged, softened or peeled
What precautions should be taken to minimize contamination during replacement of a hydraulic unit ?
All lines should be plugged or capped after disconnecting
What would cause a hydraulic filter to go into open by pass, allowing unfiltered fluid into the system ?
A clogged filter
What are two types of engine driven hydraulic pumps ?
Constant and Variable delivery
How does a gear type power pump operate ?
Two meshed gears are driver by a power unit rotating in a housing. Fluid is carried around the outside of the gears and delivered to the outlet side as the gear rotate
What feature is built into a hydraulic pump drive system to prevent engine damage in the event of pump seizure or overload ?
A shear action in the pump drive shaft occurs
What is the purpose of a pressure regulator ?
To manage the output of the pump, maintain system pressure and allow the pump to turn without resistances (unloading)
What is used in some hydraulic systems to supplement the power pump when several units are operated at the same time (High Demand)
An accumulator
What are the different types of accumulators ?
Piston, Diaphragm, Bladder
What must be accomplished with any accumulator prior to disassembling ?
Make sure the air or preload has been discharged
For what purpose are pneumatic systems used in some aircraft ?
To operate brakes, doors, drive pumps, engine starting
What are sources of pneumatic power ?
Storage bottles, vane type pumps, turbine engine compressor
What happens to excessive pressure in a pneumatic system ?
A relief valve will bleed air to atmosphere
