CO Steamfitter Contractor Exam
Practice Questions And Correct
Answers (Verified Answers) Plus
Rationale 2027 Q&A| Instant
Download Pdf.
1. Which condition most directly determines the required pipe size for
a low-pressure steam distribution main in a commercial heating
system?
A. The color of the pipe insulation
B. The number of pipe supports installed
C. The required steam flow, allowable pressure drop, and operating
conditions
D. The nominal diameter of the boiler outlet only
The proper steam-main size is determined from the required steam load
and acceptable pressure loss under the system’s operating conditions.
Pipe sizing based solely on the boiler outlet or physical appearance can
result in excessive pressure drop, noise, or poor system performance.
2. In a two-pipe steam heating system, what is the primary purpose of
the condensate return piping?
A. To introduce combustion air into the boiler
B. To increase steam pressure in the mains
,C. To return condensed steam and recovered water to the boiler or
condensate system
D. To eliminate the need for steam traps
Steam gives up heat as it condenses, producing condensate that must be
removed and returned appropriately. Proper condensate return
improves energy efficiency and reduces makeup-water requirements.
3. What is the principal function of a steam trap?
A. Increase boiler firing rate
B. Prevent all water from entering the system
C. Automatically discharge condensate and noncondensable gases while
retaining live steam
D. Reduce the temperature of combustion gases
A steam trap separates condensate and gases from live steam. Its
proper operation is essential for heat transfer, drainage, and protection
against water hammer and equipment damage.
4. Which type of steam trap operates by sensing the temperature
difference between steam and condensate?
A. Inverted-bucket trap
B. Float-and-thermostatic trap
C. Thermostatic trap
D. Venturi trap
,Thermostatic steam traps respond to temperature differences. They can
discharge subcooled condensate and air while remaining closed when
steam reaches the trap’s operating temperature range.
5. What is water hammer in a steam piping system?
A. A method of mechanically testing pipe strength
B. A destructive pressure shock caused by rapidly moving or collapsing
condensate
C. A device used to regulate boiler pressure
D. A normal sound produced when steam is generated
Water hammer occurs when condensate is accelerated or abruptly
stopped by changes in steam flow, pressure, or piping geometry. It can
damage valves, fittings, supports, and equipment and is often
associated with inadequate drainage.
6. Which installation practice is most effective in reducing the
potential for condensate accumulation in a horizontal steam main?
A. Installing the main completely level
B. Increasing insulation thickness only
C. Providing proper pitch and drainage points in the direction of
condensate flow
D. Installing smaller pipe immediately after the boiler
Steam mains should be arranged with appropriate pitch so gravity can
move condensate toward designated drip legs or return points. Proper
drainage is a fundamental defense against water hammer.
, 7. What is the purpose of a drip leg on a steam main?
A. Increase steam temperature
B. Store fuel for the boiler
C. Collect and provide a means of removing condensate from the steam
main
D. Reduce combustion-air requirements
A drip leg provides a low point where condensate can collect and be
removed through an appropriate trap or drainage arrangement. This
helps keep the steam main free of excessive liquid water.
8. Why should steam takeoffs generally be arranged from the upper
portion of a steam main?
A. To increase condensate flow into the branch
B. To eliminate the need for pipe insulation
C. To reduce the likelihood of carrying condensate from the main into
the branch
D. To increase the density of steam
Taking branch connections from the upper portion of a steam main helps
prevent accumulated condensate from being swept into branch piping.
This improves system reliability and reduces water-hammer risk.
9. Which device is commonly used to remove air from a steam system
during startup?
A. Check valve
B. Pressure-reducing valve
Practice Questions And Correct
Answers (Verified Answers) Plus
Rationale 2027 Q&A| Instant
Download Pdf.
1. Which condition most directly determines the required pipe size for
a low-pressure steam distribution main in a commercial heating
system?
A. The color of the pipe insulation
B. The number of pipe supports installed
C. The required steam flow, allowable pressure drop, and operating
conditions
D. The nominal diameter of the boiler outlet only
The proper steam-main size is determined from the required steam load
and acceptable pressure loss under the system’s operating conditions.
Pipe sizing based solely on the boiler outlet or physical appearance can
result in excessive pressure drop, noise, or poor system performance.
2. In a two-pipe steam heating system, what is the primary purpose of
the condensate return piping?
A. To introduce combustion air into the boiler
B. To increase steam pressure in the mains
,C. To return condensed steam and recovered water to the boiler or
condensate system
D. To eliminate the need for steam traps
Steam gives up heat as it condenses, producing condensate that must be
removed and returned appropriately. Proper condensate return
improves energy efficiency and reduces makeup-water requirements.
3. What is the principal function of a steam trap?
A. Increase boiler firing rate
B. Prevent all water from entering the system
C. Automatically discharge condensate and noncondensable gases while
retaining live steam
D. Reduce the temperature of combustion gases
A steam trap separates condensate and gases from live steam. Its
proper operation is essential for heat transfer, drainage, and protection
against water hammer and equipment damage.
4. Which type of steam trap operates by sensing the temperature
difference between steam and condensate?
A. Inverted-bucket trap
B. Float-and-thermostatic trap
C. Thermostatic trap
D. Venturi trap
,Thermostatic steam traps respond to temperature differences. They can
discharge subcooled condensate and air while remaining closed when
steam reaches the trap’s operating temperature range.
5. What is water hammer in a steam piping system?
A. A method of mechanically testing pipe strength
B. A destructive pressure shock caused by rapidly moving or collapsing
condensate
C. A device used to regulate boiler pressure
D. A normal sound produced when steam is generated
Water hammer occurs when condensate is accelerated or abruptly
stopped by changes in steam flow, pressure, or piping geometry. It can
damage valves, fittings, supports, and equipment and is often
associated with inadequate drainage.
6. Which installation practice is most effective in reducing the
potential for condensate accumulation in a horizontal steam main?
A. Installing the main completely level
B. Increasing insulation thickness only
C. Providing proper pitch and drainage points in the direction of
condensate flow
D. Installing smaller pipe immediately after the boiler
Steam mains should be arranged with appropriate pitch so gravity can
move condensate toward designated drip legs or return points. Proper
drainage is a fundamental defense against water hammer.
, 7. What is the purpose of a drip leg on a steam main?
A. Increase steam temperature
B. Store fuel for the boiler
C. Collect and provide a means of removing condensate from the steam
main
D. Reduce combustion-air requirements
A drip leg provides a low point where condensate can collect and be
removed through an appropriate trap or drainage arrangement. This
helps keep the steam main free of excessive liquid water.
8. Why should steam takeoffs generally be arranged from the upper
portion of a steam main?
A. To increase condensate flow into the branch
B. To eliminate the need for pipe insulation
C. To reduce the likelihood of carrying condensate from the main into
the branch
D. To increase the density of steam
Taking branch connections from the upper portion of a steam main helps
prevent accumulated condensate from being swept into branch piping.
This improves system reliability and reduces water-hammer risk.
9. Which device is commonly used to remove air from a steam system
during startup?
A. Check valve
B. Pressure-reducing valve
