CO Steamfitter Contractor Exam Questions
and Correct Answers (Verified Answers)
Plus Rationale 2027 Q&A| Instant
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1. What is the primary purpose of a steam trap in a steam
distribution system?
A. Increase steam pressure
B. Remove air only
C. Automatically discharge condensate and non-condensable gases
while retaining live steam
D. Add water to the steam line
Rationale: A steam trap is designed to discharge condensate and,
depending on its type, air and other non-condensables without
allowing significant amounts of live steam to escape. Proper
condensate removal helps maintain system efficiency and prevents
water hammer.
, 2. Which condition is most likely to cause water hammer in a steam
piping system?
A. Properly sloped piping
B. Adequate condensate drainage
C. Accumulated condensate being accelerated by moving steam
D. Correctly sized steam traps
Rationale: Water hammer occurs when liquid condensate is carried at
high velocity and suddenly changes direction or impacts fittings,
valves, or pipe ends. Proper drainage, slope, and functioning traps
help minimize this hazard.
3. What is the main function of a pressure-reducing valve in a steam
system?
A. Increase downstream pressure
B. Remove condensate
C. Maintain a lower, controlled downstream pressure
D. Prevent all thermal expansion
Rationale: A pressure-reducing valve regulates a higher inlet pressure
to a lower downstream pressure. This protects equipment and allows
steam to be supplied at the pressure required by the application.
4. Why are steam pipes generally installed with a slope?
,A. To increase steam temperature
B. To prevent pipe expansion
C. To allow condensate to drain toward designated collection points
D. To increase the pipe's weight
Rationale: Steam piping must provide a path for condensate to flow
by gravity. Proper slope reduces condensate accumulation and helps
prevent water hammer and poor heat transfer.
5. Which type of valve is commonly used for throttling steam flow?
A. Check valve
B. Globe valve
C. Drain valve
D. Float valve
Rationale: Globe valves are designed for regulating flow because their
internal configuration provides relatively precise control. Gate valves,
by contrast, are generally intended for fully open or fully closed
service.
6. What is the principal purpose of a steam separator?
A. Increase boiler pressure
B. Remove entrained moisture from steam
, C. Add chemicals to condensate
D. Reduce pipe diameter
Rationale: Steam separators remove water droplets carried with
steam. Drier steam improves heat-transfer performance and helps
protect downstream equipment from erosion and water hammer.
7. Which device prevents reverse flow in a steam or condensate
line?
A. Globe valve
B. Gate valve
C. Check valve
D. Pressure-reducing valve
Rationale: A check valve permits flow in one direction and
automatically closes when flow attempts to reverse. This protects
equipment and helps prevent unwanted circulation.
8. What is the primary purpose of a steam pressure gauge?
A. Measure pipe thickness
B. Measure condensate volume
C. Indicate the pressure within the steam system
D. Measure steam velocity directly
and Correct Answers (Verified Answers)
Plus Rationale 2027 Q&A| Instant
Download Pdf
1. What is the primary purpose of a steam trap in a steam
distribution system?
A. Increase steam pressure
B. Remove air only
C. Automatically discharge condensate and non-condensable gases
while retaining live steam
D. Add water to the steam line
Rationale: A steam trap is designed to discharge condensate and,
depending on its type, air and other non-condensables without
allowing significant amounts of live steam to escape. Proper
condensate removal helps maintain system efficiency and prevents
water hammer.
, 2. Which condition is most likely to cause water hammer in a steam
piping system?
A. Properly sloped piping
B. Adequate condensate drainage
C. Accumulated condensate being accelerated by moving steam
D. Correctly sized steam traps
Rationale: Water hammer occurs when liquid condensate is carried at
high velocity and suddenly changes direction or impacts fittings,
valves, or pipe ends. Proper drainage, slope, and functioning traps
help minimize this hazard.
3. What is the main function of a pressure-reducing valve in a steam
system?
A. Increase downstream pressure
B. Remove condensate
C. Maintain a lower, controlled downstream pressure
D. Prevent all thermal expansion
Rationale: A pressure-reducing valve regulates a higher inlet pressure
to a lower downstream pressure. This protects equipment and allows
steam to be supplied at the pressure required by the application.
4. Why are steam pipes generally installed with a slope?
,A. To increase steam temperature
B. To prevent pipe expansion
C. To allow condensate to drain toward designated collection points
D. To increase the pipe's weight
Rationale: Steam piping must provide a path for condensate to flow
by gravity. Proper slope reduces condensate accumulation and helps
prevent water hammer and poor heat transfer.
5. Which type of valve is commonly used for throttling steam flow?
A. Check valve
B. Globe valve
C. Drain valve
D. Float valve
Rationale: Globe valves are designed for regulating flow because their
internal configuration provides relatively precise control. Gate valves,
by contrast, are generally intended for fully open or fully closed
service.
6. What is the principal purpose of a steam separator?
A. Increase boiler pressure
B. Remove entrained moisture from steam
, C. Add chemicals to condensate
D. Reduce pipe diameter
Rationale: Steam separators remove water droplets carried with
steam. Drier steam improves heat-transfer performance and helps
protect downstream equipment from erosion and water hammer.
7. Which device prevents reverse flow in a steam or condensate
line?
A. Globe valve
B. Gate valve
C. Check valve
D. Pressure-reducing valve
Rationale: A check valve permits flow in one direction and
automatically closes when flow attempts to reverse. This protects
equipment and helps prevent unwanted circulation.
8. What is the primary purpose of a steam pressure gauge?
A. Measure pipe thickness
B. Measure condensate volume
C. Indicate the pressure within the steam system
D. Measure steam velocity directly
