Hydraulic Valve II Part B

Question 1

The most commonly used type of directional control valve used in heavy equipment hydraulic systems is the:
A. Poppet type.
B. Rotary type.
C. Sliding spool type.
D. Check Valve type.

Answer 1

C. Sliding spool type.

Question 2

In the float position, the directional control valve connects the work ports to the________.
The effect on the actuator is:__________.

Answer 2

reservoir.
The effect on the actuator is that it will follow the contours of the ground because it is not hydrostatically held in position.

Question 3

Closed center directional control valves that are supplied by fixed displacement pumps use a relief valve to limit maximum system pressure.

Answer 3

False, unloader valve.

Question 4

The main disadvantage of electrical directional control valve actuation is that is does not allow feathering of the directional control valve.

Answer 4

True

Question 5

The function of an anti-cavitation check valve is to____________________.

Answer 5

Prevent a void from forming in the actuator.

Question 6

The passage that carries pump oil flows through an open center directional control valve when it is in neutral is called the ____________ passageway.

Answer 6

series.

Question 7

State three methods of connecting an auxiliary directional control valve into an open center hydraulic system.

Answer 7

A. Use a diverter valve.
B. Use a power beyond sleeve.
C. Use a flow divider.

Question 8

Auxiliary closed center directional control valves can be connected into an existing closed center hydraulic system by connecting the auxiliary valve in:
A. Series.
B. Parallel.
C. Series-Parallel.
D. Tandem.

Answer 8

B, Parallel.

Question 9

A diverter valve is a _______ way, ______ position directional control valve.

Answer 9

three way, two position.

Question 10

A directional control valve with a hold position will:
A. Have its work ports open in the neutral positon.
B. Have its work ports closed in the neutral position.
C. Be an open center valve.
D. Be a closed center valve.

Answer 10

B. Have its work ports closed in the neutral position.

Question 11

A pressure regulating pilot controller provides accurate directional control valve movement because it regulates:
A. Pilot oil flow to the directional control valve.
B. Pump oil flow to the directional control valve.
C. Pilot pressure to the directional control valve.
D. Pump pressure to the directional control valve.

Answer 11

C. Pilot pressure to the directional control valve.

Question 12

The component that prevents a suspended load from dropping momentarily when the directional control valve is moved from the hold to the raise position is called:
A. A load check valve.
B. A circuit relief valve.
C. A system relief valve.
D. An anti-cavitation check valve.

Answer 12

A. A load check valve.

Question 13

State two advantages that directional control valve stacks have over unibody valves.

Answer 13

A. Control valves for additional functions can be easily added to the stack.
B. An individual valve can be replaced when it is damaged, rather than replacing the whole valve assembly.

Question 14

When two functions of an open center, series-parallel directional control valve are actuated at the same time, how will the actuators react?

Answer 14

The actuator with the lightest load will operate first.

Question 15

When a diverter valve is used to connect an auxiliary directional control valve into an open center hydraulic system, the main and auxiliary valve can be operated simultaneously.

Answer 15

False.