Practice Test for Maryland Stationary Engineer Exam with 200 Practice Questions and Correct Answers/ MD Stationary Engineer Practice Test

2026-2027 Practice Test for Maryland
Stationary Engineer Exam with 200 Practice
Questions and Correct Answers/ MD
Stationary Engineer Practice Test 2026-2027


1. A Grade 2 Stationary Engineer in Maryland is authorized to operate boilers up to
what maximum horsepower?
A) 100 HP
B) 300 HP
C) 500 HP
D) Unlimited
Correct Answer: C
Rationale: The Grade 2 license is a mid-tier certification in Maryland, authorizing
supervision of plants up to 500 HP; over 500 HP requires a Grade 1 license .


2. A "Steam Syphon" (pigtail) installed on a pressure gauge is designed to:
A) Increase the pressure reading
B) Protect the internal element from live steam
C) Drain condensate back to the boiler
D) Vent air from the gauge
Correct Answer: B
Rationale: The syphon creates a water seal that prevents high-temperature steam
from damaging the sensitive Bourdon tube inside the gauge .


3. Which valve is typically used for "throttling" steam flow?
A) Gate valve
B) Globe valve
C) Check valve
D) Butterfly valve

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,Correct Answer: B
Rationale: Globe valves are designed with a plug and seat that allows precise
regulation of flow; gate valves are intended for fully open or fully closed service .


4. In a fire-tube boiler, the hot gases of combustion:
A) Circulate around the outside of the tubes
B) Pass through the inside of the tubes
C) Are injected into the steam drum
D) Never touch the heating surfaces
Correct Answer: B
Rationale: In a fire-tube design, the hot gases are "inside" the tubes, and the water
is on the "outside" within the boiler shell .


5. What is the function of a "Bottom Blowdown" valve?
A) To remove surface oil
B) To increase boiler pressure
C) To remove sludge and sediment from the mud drum
D) To test the safety valve
Correct Answer: C
Rationale: Sediment settles at the lowest point of the boiler (the mud drum); the
bottom blowdown flushes these solids out to prevent scale buildup .


6. At what pressure must a boiler be equipped with two or more safety valves?
A) 15 PSI
B) 100 PSI
C) When the heating surface exceeds 500 sq. ft.
D) Only in water-tube boilers
Correct Answer: C
Rationale: ASME code requires redundancy for larger boilers to ensure that if one
valve fails, the second can relieve the full steaming capacity .




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,7. What is "Saturated Steam"?
A) Steam that is wet and heavy
B) Steam at a temperature corresponding to its pressure
C) Steam that has been heated above the boiling point
D) Steam that contains no heat
Correct Answer: B
Rationale: Saturated steam exists in equilibrium with the water it was generated
from; it is at the exact "boiling point" for that specific pressure .


8. "Water Hammer" in a steam line is most often caused by:
A) High steam pressure
B) Accumulated condensate in the pipes
C) Low water level
D) Excessive blowdown
Correct Answer: B
Rationale: When condensate pools in a pipe and steam flows over it, the steam
condenses rapidly, creating a vacuum and a violent pressure wave .


9. What is the difference between "Absolute Pressure" and "Gauge Pressure"?
A) Gauge pressure plus atmospheric pressure
B) Gauge pressure minus atmospheric pressure
C) The pressure at which water freezes
D) Boiler pressure only
Correct Answer: A
Rationale: Absolute Pressure (PSIA) is calculated by adding atmospheric pressure
(approx. 14.7 PSI) to the gauge reading (PSIG) .


10. How many BTU (British Thermal Units) are required to change one pound of
water at 212°F into one pound of steam at 212°F?
A) 144 BTU
B) 180 BTU
C) 970.3 BTU
D) 33,475 BTU
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, Correct Answer: C
Rationale: This is the "Latent Heat of Evaporation" required to change the state of
water into steam without increasing its temperature .


11. What is "Carryover" in a steam boiler?
A) Moving fuel to the burner
B) Water droplets or impurities entering the steam line
C) Excessive draft in the stack
D) Excessive fuel in the furnace
Correct Answer: B
Rationale: Carryover is often caused by high water levels or high alkalinity
(foaming), leading to dangerous water hammer or equipment damage .


12. What is "Sensible Heat"?
A) Heat that causes a change in temperature but not state
B) Heat that causes a change in state but not temperature
C) The heat content of fuel
D) Heat lost through the stack
Correct Answer: A
Rationale: Sensible heat results in a measurable temperature rise on a
thermometer .


13. A "Blowdown Tank" is required when discharging boiler water to a sewer
because:
A) Water over 140°F can damage public sewer lines
B) It increases boiler efficiency
C) It stores spare feedwater
D) It traps valuable steam
Correct Answer: A
Rationale: Many jurisdictions, including Maryland, prohibit dumping water hotter
than 140°F (60°C) into drains; the tank allows it to cool and flash off excess
pressure first .


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