CNMI Boiler Operator Certification
Exam | Questions And Answers [ plus
Rationales] | Qs & Ans 2026/27 |
Graded A
1. What is the primary function of a boiler?
A. Cool water for HVAC
B. Store fuel
C. Generate steam or hot water by applying heat to water
D. Compress air
Rationale: Boilers convert water into steam or hot water for heating or
power.
2. What is steam pressure?
A. Air density in boiler room
B. Water temperature
C. Force exerted by steam within a confined space
D. Fuel combustion rate
Rationale: Steam pressure is the force generated by vapor in the boiler
system.
,3. What is the purpose of a pressure gauge on a boiler?
A. Measure fuel level
B. Measure water hardness
C. Indicate internal steam or water pressure
D. Control combustion air
Rationale: Pressure gauges allow operators to monitor safe operating
pressure.
4. What is the most common fuel used in boilers?
A. Wood only
B. Coal only
C. Natural gas, oil, or electricity depending on system design
D. Hydrogen peroxide
Rationale: Boilers use various fuels depending on installation and design.
5. What is boiler “drum” used for?
A. Fuel storage
B. Steam color control
C. Separation and storage of steam and water mixture
D. Air compression
Rationale: The drum separates steam from water in the system.
,6. What is the function of a safety valve?
A. Increase pressure
B. Control fuel flow
C. Release excess pressure to prevent explosion
D. Cool water instantly
Rationale: Safety valves protect boilers from overpressure conditions.
7. What is boiler blowdown?
A. Starting the boiler
B. Adding fuel
C. Removing sediment and impurities from boiler water
D. Increasing steam pressure
Rationale: Blowdown helps maintain water quality and efficiency.
8. What is scale formation in a boiler?
A. Paint buildup
B. Steam production
C. Mineral deposits on internal surfaces
D. Fuel leakage
Rationale: Scale reduces heat transfer efficiency and can damage
equipment.
, 9. What is the purpose of water treatment in boilers?
A. Increase fuel use
B. Reduce pressure
C. Prevent corrosion, scale, and foaming
D. Change steam color
Rationale: Treated water improves boiler efficiency and lifespan.
10. What is a low-water cutoff device?
A. Fuel controller
B. Pressure reducer
C. Safety device that shuts down boiler when water level is too low
D. Steam vent
Rationale: Prevents overheating and damage from low water conditions.
11. What is boiler efficiency?
A. Fuel color change
B. Steam pressure only
C. Ratio of useful heat output to energy input
D. Water level only
Rationale: Efficiency measures energy performance of the boiler.
12. What is combustion?
Exam | Questions And Answers [ plus
Rationales] | Qs & Ans 2026/27 |
Graded A
1. What is the primary function of a boiler?
A. Cool water for HVAC
B. Store fuel
C. Generate steam or hot water by applying heat to water
D. Compress air
Rationale: Boilers convert water into steam or hot water for heating or
power.
2. What is steam pressure?
A. Air density in boiler room
B. Water temperature
C. Force exerted by steam within a confined space
D. Fuel combustion rate
Rationale: Steam pressure is the force generated by vapor in the boiler
system.
,3. What is the purpose of a pressure gauge on a boiler?
A. Measure fuel level
B. Measure water hardness
C. Indicate internal steam or water pressure
D. Control combustion air
Rationale: Pressure gauges allow operators to monitor safe operating
pressure.
4. What is the most common fuel used in boilers?
A. Wood only
B. Coal only
C. Natural gas, oil, or electricity depending on system design
D. Hydrogen peroxide
Rationale: Boilers use various fuels depending on installation and design.
5. What is boiler “drum” used for?
A. Fuel storage
B. Steam color control
C. Separation and storage of steam and water mixture
D. Air compression
Rationale: The drum separates steam from water in the system.
,6. What is the function of a safety valve?
A. Increase pressure
B. Control fuel flow
C. Release excess pressure to prevent explosion
D. Cool water instantly
Rationale: Safety valves protect boilers from overpressure conditions.
7. What is boiler blowdown?
A. Starting the boiler
B. Adding fuel
C. Removing sediment and impurities from boiler water
D. Increasing steam pressure
Rationale: Blowdown helps maintain water quality and efficiency.
8. What is scale formation in a boiler?
A. Paint buildup
B. Steam production
C. Mineral deposits on internal surfaces
D. Fuel leakage
Rationale: Scale reduces heat transfer efficiency and can damage
equipment.
, 9. What is the purpose of water treatment in boilers?
A. Increase fuel use
B. Reduce pressure
C. Prevent corrosion, scale, and foaming
D. Change steam color
Rationale: Treated water improves boiler efficiency and lifespan.
10. What is a low-water cutoff device?
A. Fuel controller
B. Pressure reducer
C. Safety device that shuts down boiler when water level is too low
D. Steam vent
Rationale: Prevents overheating and damage from low water conditions.
11. What is boiler efficiency?
A. Fuel color change
B. Steam pressure only
C. Ratio of useful heat output to energy input
D. Water level only
Rationale: Efficiency measures energy performance of the boiler.
12. What is combustion?
