DC 1st Class Boiler & 3rD Class
stationary steam engineer exam
100 Questions with CorreCt answers
seCtion 1: Boiler ConstruCtion, Design
& materials (Questions 1–20)
1. A Scotch Marine boiler is easily identified because it:
A. Has a cylindrical internal furnace
B. Has water inside the tubes
C. Is made of cast iron
D. Has no shell
Correct Answer: A
Rationale: A Scotch Marine boiler is easily identified because it has a cylindrical internal
furnace, also described as internally fired .
2. The ends of boiler tubes are secured to headers by:
A. Welding
B. Expanding
C. Bolting
D. Riveting
Correct Answer: B
Rationale: The ends of boiler tubes are secured to headers by expanding .
3. Although boiler tubes and boiler drums withstand the same pressure, the walls of the
boiler tubes are much thinner because:
A. The tubes are made of stronger steel
B. The tubes are much smaller in diameter
C. The tubes are not under pressure
D. The tubes are supported by the drum
Correct Answer: B
Rationale: Although boiler tubes and boiler drums withstand the same pressure, the walls of
the boiler tubes are much thinner because the tubes are much smaller in diameter .
,4. A ______ boiler is a water tube boiler design with three steam and water drums on the
top and a mud drum beneath, interconnected by a large number of water tubes.
A. Stirling
B. Scotch
C. Fire-tube
D. Cast-iron
Correct Answer: A
Rationale: A Stirling boiler is a water tube boiler design with three steam and water drums
on top and a mud drum beneath, interconnected by water tubes .
5. A sectional (sinuous) header boiler is classified as which type?
A. Straight tube
B. Bent tube
C. Fire-tube
D. Cast-iron
Correct Answer: A
Rationale: A sectional (sinuous) header boiler is classified as a straight tube type .
6. In a water-tube boiler, the water primarily flows through:
A. Large horizontal tubes in the shell
B. Small tubes located in the furnace area
C. A single large drum only
D. The combustion gases themselves
Correct Answer: B
Rationale: Water-tube boilers contain many small-diameter tubes where water circulates,
exposed to furnace heat .
7. What is spalling in a boiler?
A. Scale formation on tubes
B. Corrosion of the drum
C. Deterioration occurring in the combustion chamber
D. Water carryover into steam
Correct Answer: C
Rationale: Spalling in a boiler occurs in the combustion chamber .
8. ______ is the ability of a material to return to its original shape after being deformed.
, A. Ductility
B. Resiliency
C. Elasticity
D. Plasticity
Correct Answer: B
Rationale: Resiliency is the ability of a material to return to its original shape after being
deformed .
9. ______ is the plasticity exhibited by a material under tension loading.
A. Resiliency
B. Ductility
C. Malleability
D. Brittleness
Correct Answer: B
Rationale: Ductility is the plasticity exhibited by a material under tension loading .
10. A ______ is a metal brace on an HRT boiler used to attach a wall to steel framework
that supports the wall.
A. Buckstay
B. Staybolt
C. Gusset
D. Tenon
Correct Answer: A
Rationale: A buckstay is a metal brace on an HRT boiler used to attach a wall to steel
framework .
11. A raised knob on the end of a moving blade that is peened over shrouding to ricotta
the shrouding to the blading is called a:
A. Tenon
B. Buckstay
C. Thrust runner
D. Labyrinth
Correct Answer: A
Rationale: A tenon is a raised knob on the end of a moving blade that is peened over
shrouding .
12. What is a stage in a steam turbine?
stationary steam engineer exam
100 Questions with CorreCt answers
seCtion 1: Boiler ConstruCtion, Design
& materials (Questions 1–20)
1. A Scotch Marine boiler is easily identified because it:
A. Has a cylindrical internal furnace
B. Has water inside the tubes
C. Is made of cast iron
D. Has no shell
Correct Answer: A
Rationale: A Scotch Marine boiler is easily identified because it has a cylindrical internal
furnace, also described as internally fired .
2. The ends of boiler tubes are secured to headers by:
A. Welding
B. Expanding
C. Bolting
D. Riveting
Correct Answer: B
Rationale: The ends of boiler tubes are secured to headers by expanding .
3. Although boiler tubes and boiler drums withstand the same pressure, the walls of the
boiler tubes are much thinner because:
A. The tubes are made of stronger steel
B. The tubes are much smaller in diameter
C. The tubes are not under pressure
D. The tubes are supported by the drum
Correct Answer: B
Rationale: Although boiler tubes and boiler drums withstand the same pressure, the walls of
the boiler tubes are much thinner because the tubes are much smaller in diameter .
,4. A ______ boiler is a water tube boiler design with three steam and water drums on the
top and a mud drum beneath, interconnected by a large number of water tubes.
A. Stirling
B. Scotch
C. Fire-tube
D. Cast-iron
Correct Answer: A
Rationale: A Stirling boiler is a water tube boiler design with three steam and water drums
on top and a mud drum beneath, interconnected by water tubes .
5. A sectional (sinuous) header boiler is classified as which type?
A. Straight tube
B. Bent tube
C. Fire-tube
D. Cast-iron
Correct Answer: A
Rationale: A sectional (sinuous) header boiler is classified as a straight tube type .
6. In a water-tube boiler, the water primarily flows through:
A. Large horizontal tubes in the shell
B. Small tubes located in the furnace area
C. A single large drum only
D. The combustion gases themselves
Correct Answer: B
Rationale: Water-tube boilers contain many small-diameter tubes where water circulates,
exposed to furnace heat .
7. What is spalling in a boiler?
A. Scale formation on tubes
B. Corrosion of the drum
C. Deterioration occurring in the combustion chamber
D. Water carryover into steam
Correct Answer: C
Rationale: Spalling in a boiler occurs in the combustion chamber .
8. ______ is the ability of a material to return to its original shape after being deformed.
, A. Ductility
B. Resiliency
C. Elasticity
D. Plasticity
Correct Answer: B
Rationale: Resiliency is the ability of a material to return to its original shape after being
deformed .
9. ______ is the plasticity exhibited by a material under tension loading.
A. Resiliency
B. Ductility
C. Malleability
D. Brittleness
Correct Answer: B
Rationale: Ductility is the plasticity exhibited by a material under tension loading .
10. A ______ is a metal brace on an HRT boiler used to attach a wall to steel framework
that supports the wall.
A. Buckstay
B. Staybolt
C. Gusset
D. Tenon
Correct Answer: A
Rationale: A buckstay is a metal brace on an HRT boiler used to attach a wall to steel
framework .
11. A raised knob on the end of a moving blade that is peened over shrouding to ricotta
the shrouding to the blading is called a:
A. Tenon
B. Buckstay
C. Thrust runner
D. Labyrinth
Correct Answer: A
Rationale: A tenon is a raised knob on the end of a moving blade that is peened over
shrouding .
12. What is a stage in a steam turbine?
