Hydraulic and pneumatic power systems

Question 1

What are the three principal categories of hydraulic fluid’s

Answer 1

Mineral, polyalphaolefin, phosphate Esther

Question 2

What color is mineral-based hydraulic fluid

Answer 2

Red

Question 3

How do you determine which type of hydraulic fluid to use in a specific system

Answer 3

In the aircraft maintenance manual, we’re on the instruction plate attached to the reservoir on the unit being serviced

Question 4

What will happen to the seals in a vegetable-based hydraulic system if it is serviced with mineral Base or phosphate Esther base fluids

Answer 4

Seals were swell, breakdown, and block the system

Question 5

When installing a Chevron seal what must be Considered

Answer 5

Chevron seal is directional and must be installed with the pressure going toward the open side of the seal

Question 6

When hydraulic lines have been disconnected, what precautions should be taken to prevent contamination of the system

Answer 6

I’ll hydraulic lines and fittings should be capped or plugged immediately after disconnecting

Question 7

What happens to the hydraulic fluid flow if the filter element becomes clogged with foreign material

Answer 7

There is a bypass valve which routes the hydraulic fluid directly from the inlet port to the outlet port

Question 8

What is a micron filter

Answer 8

A filter with a paper element

Question 9

Name the filter use an aircraft pneumatic systems

Answer 9

Paper pleated and screen type

Question 10

Why are some hydraulic reservoir is pressurized

Answer 10

To ensure positive flow of fluid to the engine driven pump at high altitude

Question 11

What methods are used to pressurize hydraulic reservoirs

Answer 11

Some systems use a variable displacement hydraulic pump, engine bleed air, or hydraulic system pressure acting on small piston inside the reservoir.

Another method is an aspirator or Venturi

Question 12

What are two types of accumulator housing

Answer 12

Spherical and cylindrical

Question 13

Name three types of hydraulic accumulators

Answer 13

Diaphragm, bladder, piston

Question 14

What is the purpose of a pressure relief valve in a hydraulic system

Answer 14

It is to limit the amount of pressure in the system. it is a system safety valve

Question 15

What is the purpose of unloading valve in a close hydraulic system

Answer 15

The unloading valve is designed to provide a low pressure path for the fluid flow from the pump back to the reservoir when the system has no flow requirements. The unloading valve also acts as a pressure regulator regulator

Question 16

What is the function of a wing flap overload valve

Answer 16

The purpose of the valve is to prevent possible structural damage to the flap for the flap system that might result from the flaps being lowered at excessive speed

Question 17

What is the purpose of the shareable section in a hydraulic pump

Answer 17

If the pump or disease, the Scherer section with disconnect the pump from the engine, allowing the engine to continue to operate

Question 18

What are two different types of hydraulic pumps

Answer 18

They are hand pumps in power pumps

Palms can also be classified as positive just placement, or non-positive displacement

Question 19

What pump is most suitable for low pressure pneumatic systems

Answer 19

Vein type pump

Question 20

What protects a direct pressure type hydraulic pressure gauge from pressure surges

Answer 20

A dampening device in the form of a very small restrictor is installed in the line leading to the gauge or at the inlet of the gauge itself

Question 21

What are pneumatic systems used for an aircraft

Answer 21

Pneumatic systems are sometimes used to operate breaks, open and close doors, starting, pump driving, and operating emergency devices

Question 22

What happens to the air after pneumatic system is operating

Answer 22

The air is dumped overboard

Question 23

Why should pneumatic system be purged periodically

Answer 23

To remove contamination, moisture, or oil from the components and lines

Question 24

What is the purpose of a relief valve in pneumatic system

Answer 24

The relief valve protects the system against over pressurization by venting access pressure to the atmosphere

Question 25

What is the purpose of an accumulator

Answer 25

Used to prevent hydraulic system shock went under high load demand conditions

Question 26

What is an example of a phosphate Esther base fluid

Answer 26

Skydrol