Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Fluid Power > Final Prep 1 > Flashcards

Final Prep 1 Flashcards

1
Q

F: The local atmospheric pressure is 14.7 psia. Is it possible that the gage pressure of a container can be -20 psig?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

F: What is viscosity?

A

A magnitude of internal friction. Thickness.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

F: What happens to viscosity as temperature increases and decreases?

A

Viscosity decreases as temperature increases and increases as temperature decreases.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

F: What kind of viscosity index (VI) indicates a high rate of change with temperature?

A

A low viscosity index (VI) indicates a high rate of change with temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

F: If the viscosity of the hydraulic fluid increases, what happens to the leakage of the system?

A

The leakage decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

F: At a given flow rate, the inside diameter of the pipe is increased, how will this effect the fluid velocity?

A

Increasing the inside diameter of the pipe causes the fluid velocity to decrease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

F: At a given inside diameter of the pipe, how will increasing the flow rate effect the fluid velocity?

A

Increasing the flow rate will cause the velocity to increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

F: What is the purpose of hydraulic fluid?

A

To transmit power, lubricate moving parts, seal clearances between mating parts, dissipate heat, and remove contaminants.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

F: How can you increase responsiveness of a hydraulic system?

A

You can increase responsiveness of a hydraulic system by increasing bulk modulus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

F: What does low bulk modulus indicate?

A

A high compressibility of fluids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

F: As the pressure of a hydraulic system increases, what will happen to the volumetric efficiency of the pump?

A

The volumetric efficiency will decrease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

F: Gear pumps give…

A

constant output with constant RPM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

F: Increasing the angle of the swashplate in a variable displacement piston pump will do what to the displacement of the pump?

A

It will increase the displacement of the pump

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

F: How do variable displacement piston pumps change the output flow?

A

By changing either the pumps RPM and/or swashplate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

F: How do variable displacement piston pumps increase the flow?

A

By increasing the angle of the swash plate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

F: Are vane pumps always fixed displacement?

A

No, they can be variable displacement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

F: Why are centrifugal pumps not used as hydraulic pumps?

A

Because their output (flow rate) is reduced as system pressure increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

F: Name all the types of pumps, if they are positive displacement or not, if they are always fixed displacement.

A

Gear pump, yes PD, yes always fixed displacement.
Vane pump, yes PD.
Piston pump, yes PD.
A centrifugal pump, not PD.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

F: What is a positive displacement pump’s output flow rate almost independent of?

A

It is almost independent of the system pressure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

F: Will changing the flow rate to an actuator have an effect on the actuator speed?

A

Yes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

F: With the same pressure, when will a double acting single rod cylinder produce more force? (extending or retracting)

A

It will produce more force on extending.

22
Q

F: What are hydraulic motors rated according to?

A

displacement, torque capacity, and maximum pressure.

23
Q

F: At a given flow rate to a variable displacement piston motor, how will increasing the angle of the swashplate effect the rotation speed of the motor?

A

It will decrease the rotation speed of the motor.

24
Q

F: Hydraulic gear motors give

A

constant rpm with constant input flowrate

25
Q

F: At the same input flow rate, will a double acting single rod cylinder run faster on extension or retraction?

A

On retraction.

26
Q

F: For a double acting double rod cylinder, does regeneration increase the extension speed?

A

No, regeneration does not increase the extension speed.

27
Q

F: What does a relief valve control?

A

Maximum system pressure

28
Q

F: What is the first stage of a pilot operated relief valve?

A

A small direct acting relief valve

29
Q

F: What normally state is a sequence valve?

A

A sequence valve is normally closed.

30
Q

F: A 4-way valve has how many ports?

A

4 ports

31
Q

F: What happens when an unloading valve opens?

A

It directs flow directly back to the tank.

32
Q

F: What is used to control the rate of a cylinder with an overrunning load?

A

A counterbalance valve

33
Q

F: What is the two purposes of the brake valve?

A

It prevents a load from overrunning the motor, and when the directional control valve is centered, it brings the motor to a stop at a controlled rate of speed.

34
Q

F: How is dynamic braking achieved?

A

When the directional control valve is centered, the brake valve allows a controlled amount of back pressure to build in line between the motor and the brake valve to achieve dynamic braking.

35
Q

F: When does flow through a needle valve vary?

A

If the differential pressure across the valve varies

36
Q

F: How does a pressure compensated flow control valve maintain a constant flow?

A

by maintaining constant pressure upstream from the valve.

37
Q

F: Check valves are classified as what?

A

Directional control valves

38
Q

F: Pilot operated check valves use what to do what?

A

use an external pilot to allow reverse flow to pass through a valve

39
Q

F: What is the concern with Meter-out? Is it the same with Meter-in?

A

Meter-out flow control will have a safety concern about the pressure intensification. Meter-in does not have this concern.

40
Q

F: Regardless of type of pump, pumps generate flow. The output pressure of the pump is the result of what?

A

Resistance to flow.

41
Q

F: High-low systems operate at what?

A

High pressure and low flow rate or high flow rate and low pressure.

42
Q

F: What do reservoirs do?

A

Help to condition hydraulic fluid (such as cooling the hydraulic fluid, removing air and water from the fluid) and store the fluid.

43
Q

F: Does the return line to the reservoir need to be above the fluid level in the reservoir?

A

No

44
Q

F: What are two common applications for accumulators?

A

To store energy in a hydraulic circuit and to absorb the shock

45
Q

F: What hydraulic conduits should be used if the components being connected move relative to each other?

A

Hoses

46
Q

P: When installing a flow control in circuit to control the speed of a pneumatic cylinder, how is it best to connect it in the line?

A

To meter the air out.

47
Q

P: What does 5/2 valve mean?

A

5 ways and 2 positions

48
Q

P: By what percent is a pneumatic receiver usually oversized?

A

By 50%

49
Q

P: Why is pneumatic cylinder speed considerably more difficult to predict?

A

Because of the high compressibility of air.

50
Q

P: Atmospheric air needs to be conditioned before use in a pneumatic system. What conditioning does this entail?

A

Removal of entrapped dirt, removal or water vapor, removal of heat, and incorporating oil for component lubrication.

51
Q

P: As the temperature increases, what happens to gas viscosity?

A

gas viscosity increases as temperature increases

Fluid Power (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions