Hydraulic Systems Flashcards
What does a single-acting actuator use?
It uses hydraulic pressure to move a piston in one direction only.
What does a double-acting actuator use?
It uses hydraulic pressure to move a piston in two directions.
How many directions can the fluid move through a check valve?
The check valve will only allow a fluid to move in one direction.
Where do selector valves direct fluid pressure?
Selector valves direct fluid pressure to various parts of the system or to either side of an actuator.
What are the two pumps?
1) Constant Pressure: which is operated by a control piston. (closed-centre)
2) Spur Gear: output pressure depends on RPM. (open-centre)
What do accumulators store?
Accumulators store pressure energy using compressed nitrogen.
What do accumulators do?
Even out pressure spikes, and supply emergency pressure for a limited time if a pump fails.
What does a hydraulic pressure incorporate against excessive system pressure?
High pressure relief valve.
What does the RAT (Ram Air Turbine) provide emergency hydraulic power for:
Flight controls (if EDP is lost)
Why are reservoirs pressurised?
To prevent them from boiling when altitude increases.
What will high temp/low pressure indicate?
Leak in the system.
