1st Class Power Engineer B2 Exam Questions
and Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
1. What is the primary purpose of a boiler safety valve?
A. To regulate steam pressure
B. To prevent the boiler pressure from exceeding its maximum
allowable working pressure (MAWP)
C. To increase steam production
D. To control feedwater temperature
Rationale: A safety valve is the last line of defense against
overpressure. It automatically opens when pressure reaches its set
point, preventing dangerous pressure buildup that could damage the
boiler or cause an explosion. Operators must never adjust or block a
safety valve without authorization.
2. Which boiler component separates steam from water before
steam leaves the steam drum?
,A. Economizer
B. Superheater
C. Steam separator
D. Downcomer
Rationale: Steam separators remove entrained water droplets from
saturated steam, ensuring dry steam enters downstream equipment.
Dry steam improves turbine efficiency, reduces erosion, and protects
piping from water hammer.
3. In a water-tube boiler, water flows through:
A. Large furnace tubes only
B. Tubes surrounded by hot combustion gases
C. External piping exclusively
D. Air ducts inside the furnace
Rationale: Water-tube boilers circulate water inside tubes while
combustion gases flow around them. This design allows higher
pressures, greater steam capacities, and faster response compared to
fire-tube boilers.
4. What is the purpose of an economizer?
,A. To cool the steam
B. To increase furnace draft
C. To preheat feedwater using waste heat from flue gases
D. To separate condensate from steam
Rationale: An economizer recovers heat from exhaust gases that
would otherwise be wasted. Preheating feedwater reduces fuel
consumption, increases boiler efficiency, and lowers stack
temperatures.
5. Which instrument measures boiler drum water level?
A. Pressure gauge
B. Thermocouple
C. Gauge glass (water column)
D. Flow meter
Rationale: A gauge glass provides operators with a direct visual
indication of boiler water level. Maintaining proper water level is
essential for safe operation because low water can expose heating
surfaces, while high water can carry moisture into the steam system.
6. Boiler blowdown is primarily performed to:
, A. Increase boiler pressure
B. Lower steam temperature
C. Control dissolved and suspended solids in boiler water
D. Increase fuel efficiency directly
Rationale: Blowdown removes concentrated impurities that
accumulate during steam generation. Proper blowdown minimizes
scaling, corrosion, foaming, and carryover while maintaining water
chemistry within recommended limits.
7. Which combustion condition generally produces the highest
carbon monoxide levels?
A. Excess air
B. Perfect combustion
C. Insufficient combustion air
D. High feedwater temperature
Rationale: Carbon monoxide forms when insufficient oxygen is
available for complete combustion. Maintaining proper air-to-fuel
ratios minimizes CO emissions and maximizes combustion efficiency.
8. The purpose of a deaerator is to remove:
and Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
1. What is the primary purpose of a boiler safety valve?
A. To regulate steam pressure
B. To prevent the boiler pressure from exceeding its maximum
allowable working pressure (MAWP)
C. To increase steam production
D. To control feedwater temperature
Rationale: A safety valve is the last line of defense against
overpressure. It automatically opens when pressure reaches its set
point, preventing dangerous pressure buildup that could damage the
boiler or cause an explosion. Operators must never adjust or block a
safety valve without authorization.
2. Which boiler component separates steam from water before
steam leaves the steam drum?
,A. Economizer
B. Superheater
C. Steam separator
D. Downcomer
Rationale: Steam separators remove entrained water droplets from
saturated steam, ensuring dry steam enters downstream equipment.
Dry steam improves turbine efficiency, reduces erosion, and protects
piping from water hammer.
3. In a water-tube boiler, water flows through:
A. Large furnace tubes only
B. Tubes surrounded by hot combustion gases
C. External piping exclusively
D. Air ducts inside the furnace
Rationale: Water-tube boilers circulate water inside tubes while
combustion gases flow around them. This design allows higher
pressures, greater steam capacities, and faster response compared to
fire-tube boilers.
4. What is the purpose of an economizer?
,A. To cool the steam
B. To increase furnace draft
C. To preheat feedwater using waste heat from flue gases
D. To separate condensate from steam
Rationale: An economizer recovers heat from exhaust gases that
would otherwise be wasted. Preheating feedwater reduces fuel
consumption, increases boiler efficiency, and lowers stack
temperatures.
5. Which instrument measures boiler drum water level?
A. Pressure gauge
B. Thermocouple
C. Gauge glass (water column)
D. Flow meter
Rationale: A gauge glass provides operators with a direct visual
indication of boiler water level. Maintaining proper water level is
essential for safe operation because low water can expose heating
surfaces, while high water can carry moisture into the steam system.
6. Boiler blowdown is primarily performed to:
, A. Increase boiler pressure
B. Lower steam temperature
C. Control dissolved and suspended solids in boiler water
D. Increase fuel efficiency directly
Rationale: Blowdown removes concentrated impurities that
accumulate during steam generation. Proper blowdown minimizes
scaling, corrosion, foaming, and carryover while maintaining water
chemistry within recommended limits.
7. Which combustion condition generally produces the highest
carbon monoxide levels?
A. Excess air
B. Perfect combustion
C. Insufficient combustion air
D. High feedwater temperature
Rationale: Carbon monoxide forms when insufficient oxygen is
available for complete combustion. Maintaining proper air-to-fuel
ratios minimizes CO emissions and maximizes combustion efficiency.
8. The purpose of a deaerator is to remove:
