Quiz on Chapter 9: Relief and Unloading Pressure Controls

1. Components in a fixed-volume pump circuit are protected from excess pressure by a : . .

1. relief valve.
2. counterbalance valve.
3. reducing valve.

2. Direct acting relief valves have ___________ response time than a pilot-operated relief valve.

1. slower
2. the same
3. faster

3. Pilot-operated relief valves have ___________ pressure override as a direct-acting relief valve.

1. more
2. less
3. the same

4. Solenoid-operated relief valves can be made from:

1. direct acting relief valves.
2. pilot operated relief valves.
3. either type relief valve.

5. A vent port is found on:

1. pilot-operated relief valves.
2. direct-acting relief valves.
3. either type relief valve.

6. Solenoidoperated relief valves can be used:

1. on the case drain of a pump.
2. on the tank line of a pump.
3. to unload the pressure port of a pump.

7. Unloading valves are commonly found in:

1. pressure-compensated pump circuits.
2. hydraulic motor circuits.
3. hi-lo pump circuits.

8. An unloading valve is set for higher pressure than the relief valve in a hi-lo pump circuit.

1. True
2. False

9. Unloading valves are different from relief valves because they:

1. are externally piloted.
2. do not control pressure.
3. Are normally open.

10. Using a hi-lo pump circuit:

1. requires less horsepower.
2. requires more horsepower.
3. requires about the same horsepower.