Maryland Stationary Engineer – Grade 1
Exam ACTUAL Exam ALL 200 QUESTIONS
AND CORRECT ANSWERS LATEST
UPDATE THIS YEAR
1. The most important safety device on a boiler is the:
A) Pressure gauge
B) Low-water cutoff
C) Safety valve
D) Temperature control
Correct ,,,answer,,,: C
Rationale: The safety valve is the primary overpressure protection device required
by ASME Code. It prevents boiler pressure from exceeding the MAWP (Maximum
Allowable Working Pressure).
2. In a watertube boiler, natural circulation is primarily achieved by:
A) Feedwater and condensate density difference
B) Steam and water density difference in downcomer and riser tubes
C) Saturated steam and superheated steam density
D) Water in mud drum and steam drum density
Correct ,,,answer,,,: B
Rationale: Cooler, denser water falls in downcomers; hotter, lighter water-steam
mixture rises in risers, creating natural circulation (thermosiphon effect).
,3. A sudden drop in boiler water level could indicate:
A) Normal operation
B) Plugged safety valve
C) Feedwater failure or broken steam line
D) High water level
Correct ,,,answer,,,: C
Rationale: Loss of feedwater or a ruptured steam line rapidly lowers water level.
This is an emergency requiring immediate shutdown.
4. The lowest visible part of the water gauge glass on a steam boiler indicates:
A) Normal water level
B) Highest safe water level
C) Lowest permissible water level
D) Point for bottom blowdown
Correct ,,,answer,,,: C
Rationale: Operating below the lowest visible point risks exposing the crown
sheet or furnace tubes, leading to catastrophic failure.
5. When taking a high-pressure steam boiler out of service for an extended
period, the recommended method is:
A) Wet lay-up
B) Dry lay-up
,C) Hot lay-up
D) Open lay-up
Correct ,,,answer,,,: B
Rationale: Dry lay-up prevents oxygen corrosion during long outages by draining,
cleaning, drying, and using desiccant.
6. The primary purpose of boiler blowdown is to:
A) Lower steam pressure
B) Remove sludge and dissolved solids
C) Increase water level
D) Test safety valve
Correct ,,,answer,,,: B
Rationale: Blowdown controls total dissolved solids (TDS) and removes sludge,
preventing carryover, foaming, and scale.
7. What is the primary function of a deaerator?
A) Preheat feedwater
B) Remove dissolved oxygen and non-condensable gases
C) Store condensate
D) Reduce feedwater hardness
Correct ,,,answer,,,: B
Rationale: Deaerators use heat and mechanical agitation to reduce oxygen to
<0.005 cc/L, preventing oxygen pitting corrosion.
, 8. The chemical most commonly used as an oxygen scavenger in boiler water
treatment is:
A) Sodium hydroxide
B) Sodium sulfite
C) Sodium phosphate
D) Chelating agents
Correct ,,,answer,,,: B
Rationale: Sodium sulfite reacts with dissolved oxygen to form harmless sodium
sulfate.
9. "Caustic embrittlement" is caused by:
A) High dissolved oxygen
B) Low pH (acidic) water
C) High sodium hydroxide concentration
D) Oils and fats
Correct ,,,answer,,,: C
Rationale: High caustic soda (NaOH) at stressed metal grain boundaries causes
cracking, especially near riveted seams.
10. Total hardness (ppm) with Ca=60 ppm and Mg=18 ppm is:
A) 78 ppm
B) 150 ppm
Exam ACTUAL Exam ALL 200 QUESTIONS
AND CORRECT ANSWERS LATEST
UPDATE THIS YEAR
1. The most important safety device on a boiler is the:
A) Pressure gauge
B) Low-water cutoff
C) Safety valve
D) Temperature control
Correct ,,,answer,,,: C
Rationale: The safety valve is the primary overpressure protection device required
by ASME Code. It prevents boiler pressure from exceeding the MAWP (Maximum
Allowable Working Pressure).
2. In a watertube boiler, natural circulation is primarily achieved by:
A) Feedwater and condensate density difference
B) Steam and water density difference in downcomer and riser tubes
C) Saturated steam and superheated steam density
D) Water in mud drum and steam drum density
Correct ,,,answer,,,: B
Rationale: Cooler, denser water falls in downcomers; hotter, lighter water-steam
mixture rises in risers, creating natural circulation (thermosiphon effect).
,3. A sudden drop in boiler water level could indicate:
A) Normal operation
B) Plugged safety valve
C) Feedwater failure or broken steam line
D) High water level
Correct ,,,answer,,,: C
Rationale: Loss of feedwater or a ruptured steam line rapidly lowers water level.
This is an emergency requiring immediate shutdown.
4. The lowest visible part of the water gauge glass on a steam boiler indicates:
A) Normal water level
B) Highest safe water level
C) Lowest permissible water level
D) Point for bottom blowdown
Correct ,,,answer,,,: C
Rationale: Operating below the lowest visible point risks exposing the crown
sheet or furnace tubes, leading to catastrophic failure.
5. When taking a high-pressure steam boiler out of service for an extended
period, the recommended method is:
A) Wet lay-up
B) Dry lay-up
,C) Hot lay-up
D) Open lay-up
Correct ,,,answer,,,: B
Rationale: Dry lay-up prevents oxygen corrosion during long outages by draining,
cleaning, drying, and using desiccant.
6. The primary purpose of boiler blowdown is to:
A) Lower steam pressure
B) Remove sludge and dissolved solids
C) Increase water level
D) Test safety valve
Correct ,,,answer,,,: B
Rationale: Blowdown controls total dissolved solids (TDS) and removes sludge,
preventing carryover, foaming, and scale.
7. What is the primary function of a deaerator?
A) Preheat feedwater
B) Remove dissolved oxygen and non-condensable gases
C) Store condensate
D) Reduce feedwater hardness
Correct ,,,answer,,,: B
Rationale: Deaerators use heat and mechanical agitation to reduce oxygen to
<0.005 cc/L, preventing oxygen pitting corrosion.
, 8. The chemical most commonly used as an oxygen scavenger in boiler water
treatment is:
A) Sodium hydroxide
B) Sodium sulfite
C) Sodium phosphate
D) Chelating agents
Correct ,,,answer,,,: B
Rationale: Sodium sulfite reacts with dissolved oxygen to form harmless sodium
sulfate.
9. "Caustic embrittlement" is caused by:
A) High dissolved oxygen
B) Low pH (acidic) water
C) High sodium hydroxide concentration
D) Oils and fats
Correct ,,,answer,,,: C
Rationale: High caustic soda (NaOH) at stressed metal grain boundaries causes
cracking, especially near riveted seams.
10. Total hardness (ppm) with Ca=60 ppm and Mg=18 ppm is:
A) 78 ppm
B) 150 ppm
