Alberta Boiler Operator (Fourth Class)
Certification Exam Questions And
Correct Answers With Rationales
1. Which of the following is the primary purpose of a boiler’s safety
valve?
A) To regulate fuel flow
B) To maintain water level
C) To prevent overpressure
D) To control combustion
Rationale: The safety valve automatically opens to release steam if
pressure exceeds safe limits, preventing potential boiler explosions.
2. The term “blowdown” in a boiler refers to:
A) Starting the boiler
B) Removing sediment and impurities from the water
C) Shutting down the boiler
D) Increasing fuel efficiency
Rationale: Blowdown removes sludge and dissolved solids to prevent
scale and corrosion.
3. The function of a boiler feedwater pump is to:
A) Burn fuel efficiently
B) Measure pressure
C) Remove condensate
D) Supply water to the boiler at the required pressure
Rationale: Feedwater pumps ensure the boiler has adequate water at
proper pressure for steam generation.
,4. What is the main reason for preheating feedwater?
A) To reduce boiler size
B) To improve thermal efficiency
C) To reduce water hardness
D) To cool the steam
Rationale: Preheating feedwater reduces fuel consumption by
lowering the energy needed to convert water into steam.
5. Which type of boiler is typically used for small-scale heating and low-
pressure applications?
A) Water-tube boiler
B) Flash boiler
C) Fire-tube boiler
D) Electric boiler
Rationale: Fire-tube boilers are simple, compact, and ideal for low-
pressure heating applications.
6. What does the term “superheated steam” mean?
A) Steam with water droplets
B) Steam heated beyond its saturation temperature
C) Steam at 100°C
D) Steam at low pressure
Rationale: Superheated steam is dry steam heated beyond the boiling
point, improving efficiency and reducing condensation in pipes.
7. The purpose of a low-water cutoff device is to:
A) Increase pressure
B) Shut down the burner when water falls below safe level
C) Regulate temperature
D) Measure flow rate
Rationale: Low-water cutoffs prevent the boiler from running dry,
which could cause overheating and damage.
8. The term “combustion efficiency” measures:
A) Heat lost through boiler walls
B) How effectively fuel energy is converted to steam
C) Boiler pressure
D) Water level fluctuation
Rationale: Combustion efficiency assesses fuel usage effectiveness by
measuring unburned fuel and heat loss.
, 9. Which of the following is a common method of controlling boiler
pressure?
A) Feedwater pump speed
B) Combustion air intake
C) Modulating the fuel input
D) Blowdown frequency
Rationale: Adjusting fuel flow helps maintain desired steam pressure.
10. What is the purpose of a boiler economizer?
A) Increase water pressure
B) Generate electricity
C) Recover heat from flue gases to preheat feedwater
D) Prevent corrosion
Rationale: Economizers improve efficiency by transferring heat from
exhaust gases to feedwater.
11. Carbon monoxide in boiler exhaust is an indication of:
A) Perfect combustion
B) High efficiency
C) Incomplete combustion
D) High water level
Rationale: CO forms when fuel does not burn completely, indicating
insufficient oxygen or poor burner performance.
12. The term “steam drum” is associated with which type of boiler?
A) Fire-tube boiler
B) Water-tube boiler
C) Flash boiler
D) Electric boiler
Rationale: In water-tube boilers, the steam drum separates steam
from water.
13. What is the recommended way to prevent scale formation in a
boiler?
A) Use raw water
B) Treat the water chemically
C) Increase fuel input
D) Reduce pressure
Rationale: Chemical treatment prevents mineral deposits, protecting
heat transfer surfaces.
Certification Exam Questions And
Correct Answers With Rationales
1. Which of the following is the primary purpose of a boiler’s safety
valve?
A) To regulate fuel flow
B) To maintain water level
C) To prevent overpressure
D) To control combustion
Rationale: The safety valve automatically opens to release steam if
pressure exceeds safe limits, preventing potential boiler explosions.
2. The term “blowdown” in a boiler refers to:
A) Starting the boiler
B) Removing sediment and impurities from the water
C) Shutting down the boiler
D) Increasing fuel efficiency
Rationale: Blowdown removes sludge and dissolved solids to prevent
scale and corrosion.
3. The function of a boiler feedwater pump is to:
A) Burn fuel efficiently
B) Measure pressure
C) Remove condensate
D) Supply water to the boiler at the required pressure
Rationale: Feedwater pumps ensure the boiler has adequate water at
proper pressure for steam generation.
,4. What is the main reason for preheating feedwater?
A) To reduce boiler size
B) To improve thermal efficiency
C) To reduce water hardness
D) To cool the steam
Rationale: Preheating feedwater reduces fuel consumption by
lowering the energy needed to convert water into steam.
5. Which type of boiler is typically used for small-scale heating and low-
pressure applications?
A) Water-tube boiler
B) Flash boiler
C) Fire-tube boiler
D) Electric boiler
Rationale: Fire-tube boilers are simple, compact, and ideal for low-
pressure heating applications.
6. What does the term “superheated steam” mean?
A) Steam with water droplets
B) Steam heated beyond its saturation temperature
C) Steam at 100°C
D) Steam at low pressure
Rationale: Superheated steam is dry steam heated beyond the boiling
point, improving efficiency and reducing condensation in pipes.
7. The purpose of a low-water cutoff device is to:
A) Increase pressure
B) Shut down the burner when water falls below safe level
C) Regulate temperature
D) Measure flow rate
Rationale: Low-water cutoffs prevent the boiler from running dry,
which could cause overheating and damage.
8. The term “combustion efficiency” measures:
A) Heat lost through boiler walls
B) How effectively fuel energy is converted to steam
C) Boiler pressure
D) Water level fluctuation
Rationale: Combustion efficiency assesses fuel usage effectiveness by
measuring unburned fuel and heat loss.
, 9. Which of the following is a common method of controlling boiler
pressure?
A) Feedwater pump speed
B) Combustion air intake
C) Modulating the fuel input
D) Blowdown frequency
Rationale: Adjusting fuel flow helps maintain desired steam pressure.
10. What is the purpose of a boiler economizer?
A) Increase water pressure
B) Generate electricity
C) Recover heat from flue gases to preheat feedwater
D) Prevent corrosion
Rationale: Economizers improve efficiency by transferring heat from
exhaust gases to feedwater.
11. Carbon monoxide in boiler exhaust is an indication of:
A) Perfect combustion
B) High efficiency
C) Incomplete combustion
D) High water level
Rationale: CO forms when fuel does not burn completely, indicating
insufficient oxygen or poor burner performance.
12. The term “steam drum” is associated with which type of boiler?
A) Fire-tube boiler
B) Water-tube boiler
C) Flash boiler
D) Electric boiler
Rationale: In water-tube boilers, the steam drum separates steam
from water.
13. What is the recommended way to prevent scale formation in a
boiler?
A) Use raw water
B) Treat the water chemically
C) Increase fuel input
D) Reduce pressure
Rationale: Chemical treatment prevents mineral deposits, protecting
heat transfer surfaces.
