Multiple Choice
Identify the
choice that best completes the statement or answers the question.
|
|
|
1.
|
Sequence valves are most often used to ________________.
a. | replace a relief valve | c. | protect the pump | b. | avoid the cost of an electrical control
circuit | d. | control downstream
pressure |
|
|
|
2.
|
A check valve is sometimes used with a sequence valve to
_____________________.
a. | allow reverse flow | c. | build pressure | b. | keep the valve from leaking | d. | prevent
backflow |
|
|
|
3.
|
A check valve built into the same body with a sequency valve may be called a(n)
_________.
a. | integral check | c. | reverse flow check | b. | bypass check | d. | All of the
above |
|
|
|
4.
|
A blocked drain on a sequence valve will cause ___________.
a. | no change in function | c. | the valve to stay closed | b. | reverse flow to
occur | d. | None of the
above |
|
|
|
5.
|
The purpose of a pressure-reducing valve in a circuit is to
______________.
a. | provide for over-pressure protection | c. | sequence cylinder
action | b. | drop the pressure in a branch circuit | d. | None of the
above |
|
|
|
6.
|
The two types of PRV’s are _____________.
a. | two-way and three-way | c. | opened and closed | b. | indrict and direct | d. | pilot operated and direct
operated |
|
|
|
7.
|
A reverse flow check may be needed with a PRV because _________________.
a. | a pressure spike could close the PRV | c. | it is needed for
safety | b. | an extra valve can’t hurt anything | d. | All of the
above |
|
|
|
8.
|
Because pressure is on the downstream side of a PRV, oil will naturally seep
into the ________________.
a. | spring chamber | c. | reservoir | b. | spool | d. | tank |
|
|
|
9.
|
Cylinders are sequenced in the reverse direction using a(n)
_____________.
a. | direct-acting sequence valve | c. | two-sequence
valve | b. | pressure-reducing valve | d. | single-sequence valve |
|
|
|
10.
|
The pressure sequence valve operates on the priciple that
________________.
a. | flow takes the path of least resistance | c. | is described by Pascal’s
Law | b. | system pressure rises when an actuator becomes extended | d. | All of the
above |
|
Matching
|
|
|
Segment 1
a. | load | d. | drain | b. | external drain
line | e. | electrical | c. | pressure |
|
|
|
11.
|
The sequence valve depends on an actuator to stop and block flow so that
__________ rises to open it.
|
|
|
12.
|
Sequence valves are used to sequence two actuators to avoid the cost of a(n)
__________ control circuit.
|
|
|
13.
|
The downstream pressure of a sequence valve depends on the _________.
|
|
|
14.
|
The ______ is connected to the sequence valve’s spring chanber to keep
the pressure out.
|
|
|
15.
|
A sequence valve is actually a relief valve with a(n) __________.
|
|
|
Segment 2
a. | normally closed | d. | lock | b. | integral | e. | relief | c. | drill |
|
|
|
16.
|
A blocked drain line of a sequence valve will cause the valve to
__________.
|
|
|
17.
|
Flowing backwards through a sequence valve without a bypass check is not
possible because the valve is __________.
|
|
|
18.
|
A bypass check built into the same body of a sequence valve is call a(n)
________ check valve.
|
|
|
19.
|
A sequence valve may be used as a(n) _____________ valve.
|
|
|
20.
|
An example of a two sequence valve circuit woud be a(n) clamp and
________.
|
|
|
Segment 3
a. | CW | d. | self | b. | downstream | e. | pressure | c. | opened | f. | open |
|
|
|
21.
|
The pressure-reducing valve senses _________ pressure.
|
|
|
22.
|
To increase the downstream pressure of a PRV, you turn the adjustment knob
_______.
|
|
|
23.
|
A spring holds the PRV in a normally _________ position.
|
|
|
24.
|
A PRV is used in multiple actuator circuits to reduce the _________ in one
branch of the circuit.
|
|
|
25.
|
A PRV is in the ______ position when the adjustment pressure setting is higher
than system pressure.
|
|
|
26.
|
The _______ relieveing feature of a PRV allows excess downstream pressure to
bleed off through the drain port.
|
|
|
Segment 4
a. | check | d. | rise | b. | actuators | e. | tank | c. | spring |
|
|
|
27.
|
Downstream pressure will _________ if the external drain of a PRV is
blocked.
|
|
|
28.
|
The drain port of a PRV must always be connected directly to the l
______.
|
|
|
29.
|
To prevent a PRV from blocking flow when flowing backwards through the valve,
use a(n) _________ valve.
|
|
|
30.
|
The external drain of a PRV keeps oil pressure from building in the __________
chamber.
|
|
|
31.
|
Pressure-reducing valves can be used in any application where the process
requires one or more _________ to operate at pressures lower than the main circuit pressure.
|