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Chapter 5 Valves
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4. What type of valve uses flexible, chemical-resistant, rubber-type diaphragms
to control flow?
A. Plug
B. Ball
C. Diaphragm
D. Butterfly
5. What safety device is designed to open quickly if the pressure of a gas in a
closed space exceeds a preset limit?
A. Relief valve
B. Safety valve
C. Multiport valve
D. Block valve
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Chapter 5 Valves
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6. Which of the following is a difference between safety valves and relief valves?
A. Safety valves are used with liquid.
B. Safety valves have a faster response time.
C. Safety valves have a smaller exhaust port.
D. All of the above
7. Which of the following is one of the most common valve conditions that a
process technician may need to investigate?
A. Leakage
B. Throttling
C. Damage to valve seat
D. Valve stem seizure
Process Technology Equipment
Chapter 5 Valves
8. What should you do if discover a valve with extreme blockage?
A. Contact a supervisor.
B. Use a rod-out tool to clear the blockage.
C. Contact the maintenance department.
D. Remove the valve and its associated piping from service.
9. Which of the following is a cause of leakage?
A. Wear
B. Corrosion
C. Damage from an external source
D. All of the above
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Chapter 5 Valves
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10. Which of the following improper operations can cause off-specification
product due to improper flows?
A. Failure to clean and lubricate valve stems
B. Improper closing of a valve on a high-pressure line
C. Use of excessive force when opening or closing a valve
D. Failure to wear proper protective equipment
11. Where is the most obvious place to look for leaks and corrosion?
A. Louvers
B. Flanges
C. Valve stem
D. Valve body
12. Which of the following improper operations can lead to valve leakage?
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Chapter 5 Valves
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A. Failure to clean and lubricate valve stems
B. Improper closing of a valve on a high-pressure line
C. Use of excessive force when opening or closing a valve
D. Failure to wear proper protective equipment
1. What is the most common type of valve in the process industries?
A. Gate
B. Globe
C. Check
D. Butterfly
2. What type of valve would you use in a low-temperature, low-pressure
application?
A. Plug
B. Ball
C. Diaphragm
Process Technology Equipment
Chapter 5 Valves
D. Butterfly
3. Where on a valve does atmospheric leakage normally occur?
A. Bonnet
B. Valve body
C. Valve stem
D. Valve seat
4. What body motion should be used when adjusting a valve?
A. Pushing
B. Pulling
C. Left to right
D. Right to left
Process Technology Equipment
Chapter 5 Valves
5. What area of a valve should process technicians typically grease?
A. Bonnets
B. Valve stem
C. Flanges
D. Gaskets
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Chapter 5 Valves
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APPENDIX, Chapter 5
Table of Contents
Contents
Page
Checking Your Knowledge Answer
Key
24
Process Technology Equipment
Chapter 5 Valves
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Checking Your Knowledge Answer Key
1. Define the following terms:
a. Ball valve
b. Block valve
c. Butterfly valve
d. Check valve
e. Control valve
f. Diaphragm valve
g. Gate valve
h. Globe valve
i. Multiport valve
j. Manual valve
k. Needle valve
l. Plug valve
m. Relief valve
n. Safety valve
o. Bonnet
p. Damper
q. Handwheel
r. Louvers
s. Packing
t. Throttling
u. Valve seat
v. Valve knocker
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Chapter 5 Valves
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2. (True or False) Gate valves are the most common type of valve designed for
on/off service and NOT for throttling a process.
Process Technology Equipment
Chapter 5 Valves
3. _______ valves use a disc and seat to regulate the flow.
4. Check valves are used to prevent _________ in piping when the flow stops.
a. overflow
b. continuous flow
c. trickle flow
d. backflow
5. Which of the following are types of check valves? (Select all that apply.)
a. swing
b. lift
c. ball
d. gate
Process Technology Equipment
Chapter 5 Valves
6. (True or False) A ball valve opens completely with a quarter turn of the stem
using the valve handle.
7. (True or False) The two types of diaphragm valves are membrane diaphragm
valve and straight-through diaphragm valve.
8. A _________valve would be selected for use with extremely corrosive
materials.
a. globe
b. plug
c. diaphragm
d. ball
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Chapter 5 Valves
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9. (True or False) Safety valves operate quickly to prevent overpressurization by
gases, which can cause equipment damage or injury.
10. A _______________________ may be used to address blockage in small
valves.
a. valve wrench
b. rod-out tool
c. chain operator
d. welding rod
11. Name three causes of leakage in valves.
12. Which of the following improper operation can lead to damage to the valve
stem? (Select all that apply.)
a. Use of excessive force when opening or closing a valve
b. Failure to clean and lubricate valve stems
c. Closing a valve under high pressure
d. Closing a valve under low temperatures
Process Technology Equipment
Chapter 5 Valves
13. (True/False) Use the tool closest at hand when adjusting valves.
14. Match the valve type with its description.
I. Ball
a. Designed to open if the pressure of a gas exceeds a
preset threshold
II. Butterfly
b. Uses a disc-shaped flow control element to control flow
III. Check
c. Uses a hollowed-out plug to control flow
IV. Diaphragm
d. Uses a rubber-type diaphragm to control flow
V. Gate
e. Uses a guillotine to block the flow of fluids
VI. Globe
f. Uses a hollowed-out ball to control flow
VII. Plug
g. Designed to open if the pressure of a liquid exceeds a
preset level
VIII. Relief
h. Uses a ball, cylindrical, or needle-shaped disc to block
fluid flow
IX. Safety
i. Used to prevent accidental backflow
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15. List two of the most obvious places to look for leaks and corrosion in valves.