1st Class Power Engineer B1 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 during normal operation
• B. To prevent boiler overpressure by automatically releasing
steam
• C. To improve boiler efficiency
• D. To remove dissolved gases from boiler water
Rationale: A safety valve is the final protective device against
excessive pressure in a boiler. It automatically opens when the
pressure reaches a predetermined set point and closes after the
pressure falls to a safe level. This prevents catastrophic boiler failure
or explosion.
2. Which boiler component primarily transfers heat from combustion
gases to water?
, • A. Steam separator
• B. Water tubes or fire tubes
• C. Feedwater heater
• D. Blowdown tank
Rationale: Water-tube and fire-tube boilers transfer heat through
metal surfaces separating combustion gases from water. The design
determines efficiency, pressure capability, and steam generation
characteristics.
3. What is the primary purpose of a deaerator?
• A. Increase boiler pressure
• B. Cool condensate
• C. Remove dissolved oxygen and carbon dioxide from feedwater
• D. Separate steam from water
Rationale: Deaerators reduce dissolved oxygen and carbon dioxide,
which cause corrosion in boilers and condensate systems. Mechanical
agitation combined with heating improves gas removal efficiency.
, 4. Boiler blowdown is mainly performed to:
• A. Increase steam pressure
• B. Control dissolved and suspended solids
• C. Improve burner efficiency
• D. Increase condensate return
Rationale: Blowdown removes concentrated impurities that
accumulate as steam leaves dissolved solids behind. Proper blowdown
minimizes scaling, foaming, and carryover while maintaining water
chemistry.
5. Superheated steam differs from saturated steam because it:
• A. Contains more moisture
• B. Has a temperature above the saturation temperature
• C. Exists at lower pressure
• D. Always has lower energy
Rationale: Superheated steam has additional sensible heat beyond
saturation. It contains no moisture under equilibrium conditions and is
preferred for turbines because it reduces blade erosion.
, 6. Which instrument directly measures boiler drum water level?
• A. Pressure gauge
• B. Gauge glass
• C. Thermocouple
• D. Draft gauge
Rationale: The gauge glass provides a direct visual indication of water
level inside the boiler drum. It is an essential safety device used
alongside electronic level instrumentation.
7. What is the primary purpose of an economizer?
• A. Reduce steam temperature
• B. Recover waste heat to preheat feedwater
• C. Increase furnace draft
• D. Remove boiler scale
Rationale: An economizer captures heat from flue gases that would
otherwise be lost, increasing boiler efficiency by preheating incoming
feedwater.
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 during normal operation
• B. To prevent boiler overpressure by automatically releasing
steam
• C. To improve boiler efficiency
• D. To remove dissolved gases from boiler water
Rationale: A safety valve is the final protective device against
excessive pressure in a boiler. It automatically opens when the
pressure reaches a predetermined set point and closes after the
pressure falls to a safe level. This prevents catastrophic boiler failure
or explosion.
2. Which boiler component primarily transfers heat from combustion
gases to water?
, • A. Steam separator
• B. Water tubes or fire tubes
• C. Feedwater heater
• D. Blowdown tank
Rationale: Water-tube and fire-tube boilers transfer heat through
metal surfaces separating combustion gases from water. The design
determines efficiency, pressure capability, and steam generation
characteristics.
3. What is the primary purpose of a deaerator?
• A. Increase boiler pressure
• B. Cool condensate
• C. Remove dissolved oxygen and carbon dioxide from feedwater
• D. Separate steam from water
Rationale: Deaerators reduce dissolved oxygen and carbon dioxide,
which cause corrosion in boilers and condensate systems. Mechanical
agitation combined with heating improves gas removal efficiency.
, 4. Boiler blowdown is mainly performed to:
• A. Increase steam pressure
• B. Control dissolved and suspended solids
• C. Improve burner efficiency
• D. Increase condensate return
Rationale: Blowdown removes concentrated impurities that
accumulate as steam leaves dissolved solids behind. Proper blowdown
minimizes scaling, foaming, and carryover while maintaining water
chemistry.
5. Superheated steam differs from saturated steam because it:
• A. Contains more moisture
• B. Has a temperature above the saturation temperature
• C. Exists at lower pressure
• D. Always has lower energy
Rationale: Superheated steam has additional sensible heat beyond
saturation. It contains no moisture under equilibrium conditions and is
preferred for turbines because it reduces blade erosion.
, 6. Which instrument directly measures boiler drum water level?
• A. Pressure gauge
• B. Gauge glass
• C. Thermocouple
• D. Draft gauge
Rationale: The gauge glass provides a direct visual indication of water
level inside the boiler drum. It is an essential safety device used
alongside electronic level instrumentation.
7. What is the primary purpose of an economizer?
• A. Reduce steam temperature
• B. Recover waste heat to preheat feedwater
• C. Increase furnace draft
• D. Remove boiler scale
Rationale: An economizer captures heat from flue gases that would
otherwise be lost, increasing boiler efficiency by preheating incoming
feedwater.
