City of Omaha First Grade Stationary
Engineer Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
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A first-grade stationary engineer operating a high-pressure steam boiler
notices that the water level in the gauge glass is rapidly falling while the
burner continues firing. What is the safest immediate action?
A. Increase the fuel input to raise steam pressure quickly
B. Open the main steam valve fully to reduce pressure
C. Shut down the burner and investigate the low-water condition
D. Close the feedwater valve to stabilize the level
Correct Answer: C
The low-water condition in a boiler is a serious safety hazard because
exposed heating surfaces can overheat and fail. The burner should be shut
down immediately before investigating the cause of the low water level.
2. The primary purpose of a boiler safety valve is to:
A. Control normal operating pressure
B. Prevent the boiler from exceeding its maximum allowable working
pressure
C. Increase steam production during peak demand
D. Remove dissolved solids from boiler water
,Correct Answer: B
A safety valve protects the boiler by automatically relieving steam
pressure when it rises above a predetermined safe limit, preventing a
possible explosion.
3. In a fire-tube boiler, the hot combustion gases travel:
A. Through tubes surrounded by water
B. Through water passages inside the drum
C. Outside the boiler shell without contact with water
D. Through steam lines before entering the furnace
Correct Answer: A
A fire-tube boiler contains combustion gases inside tubes while water
surrounds the tubes, allowing heat transfer from the gases to the water.
4. The main function of boiler water treatment is to:
A. Increase fuel consumption
B. Prevent scale, corrosion, and deposits
C. Increase steam temperature beyond design limits
D. Eliminate the need for blowdown
Correct Answer: B
Proper water treatment reduces mineral deposits and corrosion, improving
boiler efficiency, reliability, and safety.
5. A boiler’s low-water cutoff device is designed to:
,A. Automatically increase feedwater pressure
B. Shut down the burner when water level becomes dangerously low
C. Increase combustion air supply
D. Maintain steam temperature
Correct Answer: B
The low-water cutoff protects the boiler from overheating by stopping fuel
firing when the water level falls below a safe point.
6. The gauge glass on a steam boiler indicates:
A. Steam temperature
B. Fuel pressure
C. Boiler water level
D. Combustion efficiency
Correct Answer: C
The gauge glass provides a direct visual indication of the water level inside
the boiler and helps operators prevent unsafe operating conditions.
7. Boiler blowdown is performed primarily to:
A. Remove accumulated dissolved solids from boiler water
B. Increase boiler pressure
C. Cool the burner assembly
D. Increase combustion efficiency
Correct Answer: A
Blowdown removes concentrated impurities from boiler water, reducing
scale formation and maintaining proper water chemistry.
, 8. A steam trap is used to:
A. Remove condensate and non-condensable gases from steam systems
B. Increase boiler firing rate
C. Control burner flame size
D. Measure steam pressure
Correct Answer: A
Steam traps automatically remove condensate while preventing
unnecessary loss of live steam from the system.
9. The purpose of a boiler feedwater pump is to:
A. Circulate combustion gases
B. Supply water to the boiler at a pressure higher than boiler pressure
C. Remove ash from the furnace
D. Reduce steam temperature
Correct Answer: B
Feedwater pumps force water into the boiler against internal pressure so
steam generation can continue safely.
10. A boiler pressure gauge should be connected to:
A. The furnace area
B. The steam space of the boiler
C. The fuel supply line
D. The blowdown tank
Correct Answer: B
Engineer Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
A first-grade stationary engineer operating a high-pressure steam boiler
notices that the water level in the gauge glass is rapidly falling while the
burner continues firing. What is the safest immediate action?
A. Increase the fuel input to raise steam pressure quickly
B. Open the main steam valve fully to reduce pressure
C. Shut down the burner and investigate the low-water condition
D. Close the feedwater valve to stabilize the level
Correct Answer: C
The low-water condition in a boiler is a serious safety hazard because
exposed heating surfaces can overheat and fail. The burner should be shut
down immediately before investigating the cause of the low water level.
2. The primary purpose of a boiler safety valve is to:
A. Control normal operating pressure
B. Prevent the boiler from exceeding its maximum allowable working
pressure
C. Increase steam production during peak demand
D. Remove dissolved solids from boiler water
,Correct Answer: B
A safety valve protects the boiler by automatically relieving steam
pressure when it rises above a predetermined safe limit, preventing a
possible explosion.
3. In a fire-tube boiler, the hot combustion gases travel:
A. Through tubes surrounded by water
B. Through water passages inside the drum
C. Outside the boiler shell without contact with water
D. Through steam lines before entering the furnace
Correct Answer: A
A fire-tube boiler contains combustion gases inside tubes while water
surrounds the tubes, allowing heat transfer from the gases to the water.
4. The main function of boiler water treatment is to:
A. Increase fuel consumption
B. Prevent scale, corrosion, and deposits
C. Increase steam temperature beyond design limits
D. Eliminate the need for blowdown
Correct Answer: B
Proper water treatment reduces mineral deposits and corrosion, improving
boiler efficiency, reliability, and safety.
5. A boiler’s low-water cutoff device is designed to:
,A. Automatically increase feedwater pressure
B. Shut down the burner when water level becomes dangerously low
C. Increase combustion air supply
D. Maintain steam temperature
Correct Answer: B
The low-water cutoff protects the boiler from overheating by stopping fuel
firing when the water level falls below a safe point.
6. The gauge glass on a steam boiler indicates:
A. Steam temperature
B. Fuel pressure
C. Boiler water level
D. Combustion efficiency
Correct Answer: C
The gauge glass provides a direct visual indication of the water level inside
the boiler and helps operators prevent unsafe operating conditions.
7. Boiler blowdown is performed primarily to:
A. Remove accumulated dissolved solids from boiler water
B. Increase boiler pressure
C. Cool the burner assembly
D. Increase combustion efficiency
Correct Answer: A
Blowdown removes concentrated impurities from boiler water, reducing
scale formation and maintaining proper water chemistry.
, 8. A steam trap is used to:
A. Remove condensate and non-condensable gases from steam systems
B. Increase boiler firing rate
C. Control burner flame size
D. Measure steam pressure
Correct Answer: A
Steam traps automatically remove condensate while preventing
unnecessary loss of live steam from the system.
9. The purpose of a boiler feedwater pump is to:
A. Circulate combustion gases
B. Supply water to the boiler at a pressure higher than boiler pressure
C. Remove ash from the furnace
D. Reduce steam temperature
Correct Answer: B
Feedwater pumps force water into the boiler against internal pressure so
steam generation can continue safely.
10. A boiler pressure gauge should be connected to:
A. The furnace area
B. The steam space of the boiler
C. The fuel supply line
D. The blowdown tank
Correct Answer: B
