Module 6

Question 1

The lowest fluid pressure that will open a check valve

Answer 1

Cracking pressure

Question 2

A valve in which the flow is blocked when the valve is in a nonactuated position

Answer 2

Normally closed valve

Question 3

A valve that permits fluid to flow when the valve is in a nonactuated position

Answer 3

Normally open valve

Question 4

Directional-control valves can be operated _____ or _____.

Answer 4

Manually; Automatically

Question 5

Directional-control valves are classified by the way the fluid flows when the valve is in the _____ position.

Answer 5

Center

Question 6

Many manually operated tow-way valves are not suitable for hydraulic service because of their low _____ ratings.

Answer 6

Pressure

Question 7

One disadvantage of needle valves is that they usually have high _____.

Answer 7

Pressure losses

Question 8

A direct-acting solenoid valve is a normally _____ valve.

Answer 8

Closed

Question 9

Automatic solenoid valves that operate in high-pressure hydraulic systems are usually _____-operated.

Answer 9

Pilot

Question 10

A two-way check valve permits fluid flow in _____ direction(s).

Answer 10

One

Question 11

The lowest pressure at which a check valve will open is its _____ pressure.

Answer 11

Cracking

Question 12

A three-way diverter valve controls a hydraulic motor by serving as either an unloading device or a simple _____ valve.

Answer 12

On/Off

Question 13

A normally open three-way valve permits flow to the cylinder when the valve is in a(n) _____ position.

Answer 13

Nonactuated

Question 14

A four-way valve has _____ primary working connections.

Answer 14

Four

Question 15

Most four-way valves are manufactured with _____ operating positions.

Answer 15

Three

Question 16

A three-position, four-way valve is called a(n) _____ valve.

Answer 16

Closed crossover

Question 17

A five-way valve is usually a variation of a(n) _____ valve.

Answer 17

Four-way

Question 18

Are the exhaust ports connected internally in a five-way valve?

Answer 18

No

Question 19

A four-way spool valve that does not shift with a linear motion is a(n) _____ valve.

Answer 19

Rotary

Question 20

Directional-control valves do all of the following except

a. control fluid flow
b. move hydraulic cylinders
c. relieve excess pressure
d. stop hydraulic cylinders

Answer 20

c. relieve excess pressure.

Question 21

Directional-control valves are not classified by the number of

a. paths
b. pipe threads
c. ports
d. positions

Answer 21

b. Pipe threads.

Question 22

Some manually operated two-way valves are not suitable for hydraulic service because of their

a. low pressure ratings
b. seating design
c. slow closing speeds
d. slow opening speeds

Answer 22

a. Low pressure ratings.

Question 23

The closing force of a solenoid-operated valve is usually limited to _____ lb.

a. 5
b. 15
c. 25
d. 35

Answer 23

b. 15

Question 24

The pressure at which a check valve will start to open is called its

a. cracking pressure
b. popping pressure
c. pressure rating
d. seating pressure

Answer 24

a. Cracking pressure.

Question 25

Spool valves usually are partially balanced because of their a. actuator type b. body size c. construction d. number of internal ports

Answer 25

c. Construction.

Question 26

Three-way spool valves are made with three a. basic parts b. primary and three secondary connections c. primary connections d. secondary connections

Answer 26

c. Primary connections.

Question 27

Selector and diverter three-way valves differ from directions-control valves in their a. internal construction b. number of piping connections c. pilot connections d. pressure ratings

Answer 27

a. Internal construction.

Question 28

A three-position, four-way valve is referred to as a _____ valve. a. closed crossover b. direct control c. needle d. split-phase

Answer 28

a. Closed crossover.

Question 29

Rotary spool valves can be manufactured to operate as all of the following except _____ valves. a. two-way b. three-way c. four-way d. five-way

Answer 29

d. Five-way.