BOILER OPERATOR LICENSING
EXAMINATION QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS) PLUS
RATIONALES 2026 Q&A | INSTANT
DOWNLOAD PDF
1. What is the primary purpose of a boiler?
A. To cool water
B. To store steam
C. To generate steam or hot water by applying heat
D. To filter impurities
Answer: C
Rationale: A boiler’s main function is to convert water into steam or hot
water using heat energy.
2. Which fuel is most commonly used in industrial boilers?
A. Wood
B. Coal only
C. Natural gas
D. Solar energy
Answer: C
Rationale: Natural gas is widely used due to efficiency, availability, and
cleaner combustion.
3. What device prevents excessive pressure buildup in a boiler?
A. Pressure gauge
B. Feedwater pump
C. Safety valve
D. Blowdown valve
Answer: C
, Rationale: The safety valve automatically releases pressure to prevent
explosion.
4. The normal water level in a boiler is indicated by the:
A. Thermometer
B. Pressure switch
C. Gauge glass
D. Safety valve
Answer: C
Rationale: The gauge glass provides a visual indication of boiler water
level.
5. Low water conditions in a boiler can cause:
A. Increased efficiency
B. Improved heat transfer
C. Overheating and boiler damage
D. Reduced fuel use
Answer: C
Rationale: Low water exposes boiler metal surfaces, leading to
overheating and failure.
6. What type of boiler has water inside tubes and hot gases outside?
A. Fire-tube boiler
B. Water-tube boiler
C. Cast iron boiler
D. Electric boiler
Answer: B
Rationale: In water-tube boilers, water circulates inside tubes heated
externally by combustion gases.
7. What is the function of a boiler blowdown?
A. Increase pressure
B. Add chemicals
C. Remove sediment and control water quality
D. Reduce steam temperature
, Answer: C
Rationale: Blowdown removes impurities to prevent scale and corrosion.
8. The term “boiler horsepower” refers to:
A. Electrical motor power
B. Fuel consumption rate
C. Steam-generating capacity
D. Operating pressure
Answer: C
Rationale: Boiler horsepower measures the amount of steam a boiler can
produce.
9. What instrument measures boiler pressure?
A. Thermostat
B. Flow meter
C. Pressure gauge
D. Level controller
Answer: C
Rationale: Pressure gauges display internal boiler pressure for safe
operation.
10.Which condition is most dangerous in boiler operation?
A. High water level
B. Normal pressure
C. Low water level
D. Warm feedwater
Answer: C
Rationale: Low water level can cause overheating and catastrophic failure.
11.What is the function of a feedwater pump?
A. Remove steam
B. Control pressure
C. Supply water to the boiler
D. Measure temperature
EXAMINATION QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS) PLUS
RATIONALES 2026 Q&A | INSTANT
DOWNLOAD PDF
1. What is the primary purpose of a boiler?
A. To cool water
B. To store steam
C. To generate steam or hot water by applying heat
D. To filter impurities
Answer: C
Rationale: A boiler’s main function is to convert water into steam or hot
water using heat energy.
2. Which fuel is most commonly used in industrial boilers?
A. Wood
B. Coal only
C. Natural gas
D. Solar energy
Answer: C
Rationale: Natural gas is widely used due to efficiency, availability, and
cleaner combustion.
3. What device prevents excessive pressure buildup in a boiler?
A. Pressure gauge
B. Feedwater pump
C. Safety valve
D. Blowdown valve
Answer: C
, Rationale: The safety valve automatically releases pressure to prevent
explosion.
4. The normal water level in a boiler is indicated by the:
A. Thermometer
B. Pressure switch
C. Gauge glass
D. Safety valve
Answer: C
Rationale: The gauge glass provides a visual indication of boiler water
level.
5. Low water conditions in a boiler can cause:
A. Increased efficiency
B. Improved heat transfer
C. Overheating and boiler damage
D. Reduced fuel use
Answer: C
Rationale: Low water exposes boiler metal surfaces, leading to
overheating and failure.
6. What type of boiler has water inside tubes and hot gases outside?
A. Fire-tube boiler
B. Water-tube boiler
C. Cast iron boiler
D. Electric boiler
Answer: B
Rationale: In water-tube boilers, water circulates inside tubes heated
externally by combustion gases.
7. What is the function of a boiler blowdown?
A. Increase pressure
B. Add chemicals
C. Remove sediment and control water quality
D. Reduce steam temperature
, Answer: C
Rationale: Blowdown removes impurities to prevent scale and corrosion.
8. The term “boiler horsepower” refers to:
A. Electrical motor power
B. Fuel consumption rate
C. Steam-generating capacity
D. Operating pressure
Answer: C
Rationale: Boiler horsepower measures the amount of steam a boiler can
produce.
9. What instrument measures boiler pressure?
A. Thermostat
B. Flow meter
C. Pressure gauge
D. Level controller
Answer: C
Rationale: Pressure gauges display internal boiler pressure for safe
operation.
10.Which condition is most dangerous in boiler operation?
A. High water level
B. Normal pressure
C. Low water level
D. Warm feedwater
Answer: C
Rationale: Low water level can cause overheating and catastrophic failure.
11.What is the function of a feedwater pump?
A. Remove steam
B. Control pressure
C. Supply water to the boiler
D. Measure temperature
