Quiz on Chapter 12: Infinitely Variable Directional Valves

1. Infinitely variable valves are for:

  1. hydraulic circuits only.
  2. pneumatic circuits only.
  3. both hydraulic and pneumatic circuits.

2. Proportional and servo directional control valves have___________flow response than conventional directional control valves.

  1. slower
  2. the same
  3. faster

3. A hydrostat module under a proportional control valve:

  1. produces a consistent pressure at its outlet.
  2. produces a consistent flow at its outlet.
  3. sets maximum pilot pressure.

4. An LVDT on a proportional directional control valve tells the electronic control:

  1. how much flow is passing through the valve.
  2. what the pressure is at its outlet.
  3. in what position the spool is.

5. A proportional valve circuit ___________ a feedback device from the actuator it controls.

  1. may have
  2. always has
  3. never has

6. Electromechanically controlled servovalves are:

  1. more contamination tolerant.
  2. less contamination tolerant.
  3. have about the same contamination tolerance.

7. A servovalve circuit __________ has a feedback signal to the electronic controller:

  1. sometimes
  2. never
  3. always

8. Infinitely variable directional control valves should be mounted as close as possible to the actuator.

  1. True
  2. False

9. Always size infinitely variable directional control valves:

  1. with a high pressure drop.
  2. with a low pressure drop.
  3. it really does not matter what the pressure drop is.

10. A servovalve circuit for cylinder positioning uses a/an:

  1. encoder.
  2. linear transducer.