Louisiana (New Orleans) Second Class
Stationary Boilers 661-LA 661 Exam
ACTUAL EXAM COMPLETE 300
QUESTIONS AND CORRECT ANSWERS
LATEST UPDATE THIS YEAR
Question 1
What is the primary difference between a fire-tube boiler and a water-tube boiler?
A. Fire-tube boilers have water inside tubes; water-tube boilers have fire inside tubes
B. Fire-tube boilers have fire inside tubes; water-tube boilers have water inside tubes
C. There is no difference
D. Fire-tube boilers are used for steam only; water-tube for hot water only
Correct Answer: B. Fire-tube boilers have fire inside tubes; water-tube boilers have
water inside tubes
Rationale: In fire-tube boilers, hot combustion gases pass through tubes surrounded by
water. In water-tube boilers, water passes through tubes surrounded by hot gases .
Question 2
What is the function of a steam drum in a boiler?
A. Store feedwater
B. Separate steam from water
C. Collect sediment
D. Regulate pressure
Correct Answer: B. Separate steam from water
Rationale: The steam drum provides space for steam to separate from water before
leaving the boiler .
,Question 3
What is the purpose of a mud drum in a boiler?
A. Store excess steam for later use
B. Collect sediments and allow sludge removal
C. Increase the boiler's pressure rating
D. Act as a secondary steam drum
Correct Answer: B. Collect sediments and allow sludge removal
Rationale: The mud drum collects settled impurities (mud) and provides a convenient
point for blowdown and cleaning .
Question 4
What is the function of an economizer in a boiler system?
A. Preheat feedwater using flue gases
B. Superheat steam
C. Remove moisture from steam
D. Control combustion air
Correct Answer: A. Preheat feedwater using flue gases
Rationale: Economizers recover heat from flue gases to preheat feedwater, improving
boiler efficiency .
Question 5
What is the function of an air preheater?
A. Preheat combustion air using flue gases
B. Preheat feedwater
C. Superheat steam
D. Remove moisture
Correct Answer: A. Preheat combustion air using flue gases
,Rationale: Air preheaters recover heat from flue gases to warm incoming combustion
air, improving efficiency .
Question 6
What is the purpose of a superheater?
A. Increase steam temperature above saturation temperature
B. Increase steam pressure
C. Remove moisture from steam
D. Preheat feedwater
Correct Answer: A. Increase steam temperature above saturation temperature
Rationale: Superheaters raise the temperature of saturated steam to produce
superheated steam, which contains more energy and improves cycle efficiency.
Question 7
Which type of boiler uses fire tubes surrounded by water?
A. Water-tube boiler
B. Fire-tube boiler
C. Electric boiler
D. Condensing boiler
Correct Answer: B. Fire-tube boiler
Rationale: In fire-tube boilers, hot gases pass through tubes that are immersed in water,
heating the water to produce steam .
Question 8
A bent-tube water-tube boiler is distinguished from a straight-tube boiler by:
A. Use of a furnace inside the shell
B. Curved tubes that increase turbulence
, C. Higher steam pressure capability
D. Absence of a superheater
Correct Answer: B. Curved tubes that increase turbulence
Rationale: Bent-tube designs have curved tubes which promote better water circulation
and heat transfer through increased turbulence .
Question 9
What is the function of a deaerator?
A. Remove dissolved gases from feedwater
B. Add chemicals to feedwater
C. Heat feedwater
D. Filter feedwater
Correct Answer: A. Remove dissolved gases from feedwater
Rationale: Deaerators remove oxygen and other dissolved gases that cause corrosion .
Question 10
What is the purpose of a blowdown valve?
A. Remove sediment and concentrated impurities
B. Add water to the boiler
C. Regulate pressure
D. Indicate water level
Correct Answer: A. Remove sediment and concentrated impurities
Rationale: Blowdown removes concentrated impurities and sediment from the boiler .
Question 11
What is the difference between continuous blowdown and intermittent
blowdown?
Stationary Boilers 661-LA 661 Exam
ACTUAL EXAM COMPLETE 300
QUESTIONS AND CORRECT ANSWERS
LATEST UPDATE THIS YEAR
Question 1
What is the primary difference between a fire-tube boiler and a water-tube boiler?
A. Fire-tube boilers have water inside tubes; water-tube boilers have fire inside tubes
B. Fire-tube boilers have fire inside tubes; water-tube boilers have water inside tubes
C. There is no difference
D. Fire-tube boilers are used for steam only; water-tube for hot water only
Correct Answer: B. Fire-tube boilers have fire inside tubes; water-tube boilers have
water inside tubes
Rationale: In fire-tube boilers, hot combustion gases pass through tubes surrounded by
water. In water-tube boilers, water passes through tubes surrounded by hot gases .
Question 2
What is the function of a steam drum in a boiler?
A. Store feedwater
B. Separate steam from water
C. Collect sediment
D. Regulate pressure
Correct Answer: B. Separate steam from water
Rationale: The steam drum provides space for steam to separate from water before
leaving the boiler .
,Question 3
What is the purpose of a mud drum in a boiler?
A. Store excess steam for later use
B. Collect sediments and allow sludge removal
C. Increase the boiler's pressure rating
D. Act as a secondary steam drum
Correct Answer: B. Collect sediments and allow sludge removal
Rationale: The mud drum collects settled impurities (mud) and provides a convenient
point for blowdown and cleaning .
Question 4
What is the function of an economizer in a boiler system?
A. Preheat feedwater using flue gases
B. Superheat steam
C. Remove moisture from steam
D. Control combustion air
Correct Answer: A. Preheat feedwater using flue gases
Rationale: Economizers recover heat from flue gases to preheat feedwater, improving
boiler efficiency .
Question 5
What is the function of an air preheater?
A. Preheat combustion air using flue gases
B. Preheat feedwater
C. Superheat steam
D. Remove moisture
Correct Answer: A. Preheat combustion air using flue gases
,Rationale: Air preheaters recover heat from flue gases to warm incoming combustion
air, improving efficiency .
Question 6
What is the purpose of a superheater?
A. Increase steam temperature above saturation temperature
B. Increase steam pressure
C. Remove moisture from steam
D. Preheat feedwater
Correct Answer: A. Increase steam temperature above saturation temperature
Rationale: Superheaters raise the temperature of saturated steam to produce
superheated steam, which contains more energy and improves cycle efficiency.
Question 7
Which type of boiler uses fire tubes surrounded by water?
A. Water-tube boiler
B. Fire-tube boiler
C. Electric boiler
D. Condensing boiler
Correct Answer: B. Fire-tube boiler
Rationale: In fire-tube boilers, hot gases pass through tubes that are immersed in water,
heating the water to produce steam .
Question 8
A bent-tube water-tube boiler is distinguished from a straight-tube boiler by:
A. Use of a furnace inside the shell
B. Curved tubes that increase turbulence
, C. Higher steam pressure capability
D. Absence of a superheater
Correct Answer: B. Curved tubes that increase turbulence
Rationale: Bent-tube designs have curved tubes which promote better water circulation
and heat transfer through increased turbulence .
Question 9
What is the function of a deaerator?
A. Remove dissolved gases from feedwater
B. Add chemicals to feedwater
C. Heat feedwater
D. Filter feedwater
Correct Answer: A. Remove dissolved gases from feedwater
Rationale: Deaerators remove oxygen and other dissolved gases that cause corrosion .
Question 10
What is the purpose of a blowdown valve?
A. Remove sediment and concentrated impurities
B. Add water to the boiler
C. Regulate pressure
D. Indicate water level
Correct Answer: A. Remove sediment and concentrated impurities
Rationale: Blowdown removes concentrated impurities and sediment from the boiler .
Question 11
What is the difference between continuous blowdown and intermittent
blowdown?
