Page 1 of 119
Maryland Stationary Engineer Grade 1 Exam
QUESTIONS AND VERIFIED ANSWERS WITH
RATIONALES JUST RELEASED
Maryland Stationary Engineer Grade 1 Exam,
SUMMARIZED EXAM COVERAGE (point form)
• Licensing & Regulations (Maryland-Specific) – Maryland Stationary Engineers Act (Title 6.5),
COMAR 09.17.02, Maryland Boiler and Pressure Vessel Safety Act (Public Safety Article, Title 12,
Subtitle 9).
• Grade 1 Scope & Experience – Oversee operation of boilers of 500+ HP; five years documented
experience as active Grade 2 under a Grade 1; possible credit for CEUs (6 hours = 1 year), master
plumber/HVACR contractor license (1 year), professional engineer experience (1 year).
• Boiler Types & Construction – Fire-tube vs. water-tube, cast iron sectional, HRT (horizontal
return tubular), scotch marine, bent-tube, field-erected vs. package, electric boilers, waste heat
recovery.
• Steam Theory & Thermodynamics – Latent vs. sensible heat, steam quality (dryness fraction),
enthalpy, entropy, superheated steam, critical pressure.
• Boiler Safety Devices & Controls – Safety valve (ASME I), low-water cutoff (LWCO), pressure
controls, modulating combustion controls, flame safeguards (purge, ignition, flame detection),
blowback ring adjustment, feedwater regulators, gauge glass & water columns.
• Combustion Principles – Air-fuel ratio (excess air – 10-30% for gas/oil, 50% for pulverized coal),
primary/secondary air, combustion efficiency, flame stability, draft systems (natural,
mechanical, balanced).
• Water Treatment – Hardness (calcium, magnesium), scale vs. sludge, internal vs. external
treatment, blowdown (surface, bottom), pH control, oxygen scavengers (sodium sulfite),
phosphate treatment, chelants, deaeration.
• Boiler Operations & Procedures – Start-up, normal operation, shutdown, blowdown (bottom
blowdown at low load), warming up cold boiler (avoid thermal shock), hydrostatic test, lay-up
(wet vs. dry), cutting a boiler in/out of service.
• Auxiliary Equipment – Pumps (centrifugal, reciprocating, rotary), air compressors, deaerators
(remove oxygen), feedwater heaters, condensers, cooling towers, turbines, generators,
chillers/refrigeration.
• Electrical Systems – Single-phase vs. three-phase, motor types (AC/DC), fuses and breakers
(selection by load), basic motor control circuits, lockout/tagout (OSHA).
• Safety & OSHA – Confined space entry (permit, gas testing, PPE, rescue plan), lockout/tagout
(LOTO), PPE for boiler work, emergency shutdown, fire prevention (NFPA 54 fuel gas piping).
• Inspections & Maintenance – External inspection (once per shift), annual internal inspection,
LWCO/water column check (each shift), high-limit safety switch (annually), complete external
boiler inspection (once per shift), manhole clearance (5 ft minimum), overhead clearance for
package boilers (2 ft from ceiling).
QUESTION 1: A candidate for Maryland Grade 1 stationary engineer license has been working as a Grade
2 engineer under a Grade 1 for four years. He completed 12 credit hours of approved boiler safety CEUs.
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How many years of experience can he claim toward the required five years?
A) 4 years
B) 5 years
C) 6 years
D) 3 years
Answer: B – One year credit for six credit hours (12 hours = 2 years credit). 4 years actual + 2 years CEU
credit = 6 years total, but only 5 years are required; therefore meets the requirement with one year
excess .
QUESTION 2: What is the minimum horsepower threshold for a boiler to be regulated under the
Maryland Stationary Engineers Act, assuming it operates above 15 PSI?
A) 15 HP
B) 30 HP
C) 50 HP
D) 100 HP
Answer: B – The Act governs equipment operating at more than 15 PSI and 30 or more horsepower (or
1,003,000 Btu/hr steam equivalent) .
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QUESTION 3: A Grade 1 stationary engineer is responsible for operating a plant with a single 600 HP
steam boiler. What is the highest horsepower plant a Grade 1 is qualified to oversee?
A) 299 HP
B) 499 HP
C) 500 HP or more
D) 1,000 HP maximum
Answer: C – A Grade 1 license authorizes operation of 500 or more horsepower equipment (in any
building) with no stated upper limit .
QUESTION 4: During a startup, a Grade 1 engineer opens the blowdown valves to warm the boiler. What
is the correct sequence for blowdown on a cold start?
A) Open fast to clear sediment
B) Crack the valve gently, then fully open for a few seconds
C) Blow down continuously for 5 minutes
D) Do not blow down until reaching full operating pressure
Answer: B – Cracking the valve gently prevents thermal shock; fully opening briefly removes sediment.
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QUESTION 5: A fire-tube boiler is to be inspected for scale formation. Which area is most likely to
experience the heaviest scale buildup?
A) Steam drum
B) Water tubes
C) Heat transfer surfaces (tubes) on the water side
D) Superheater section
Answer: C – Scale forms where heat transfer is highest; in fire-tube boilers, the tube surfaces exposed to
hot gases on the outside and water on the inside.
QUESTION 6: An engineer notices that the boiler’s bottom blowdown line is leaking after a blowdown.
What is the immediate safety risk?
A) Loss of water level
B) Pressure drop
C) Reduced fuel efficiency
D) Corrosion only
Answer: A – A leaking bottom blowdown line can slowly drain the boiler water, leading to low water
condition and possible tube overheating.
Maryland Stationary Engineer Grade 1 Exam
QUESTIONS AND VERIFIED ANSWERS WITH
RATIONALES JUST RELEASED
Maryland Stationary Engineer Grade 1 Exam,
SUMMARIZED EXAM COVERAGE (point form)
• Licensing & Regulations (Maryland-Specific) – Maryland Stationary Engineers Act (Title 6.5),
COMAR 09.17.02, Maryland Boiler and Pressure Vessel Safety Act (Public Safety Article, Title 12,
Subtitle 9).
• Grade 1 Scope & Experience – Oversee operation of boilers of 500+ HP; five years documented
experience as active Grade 2 under a Grade 1; possible credit for CEUs (6 hours = 1 year), master
plumber/HVACR contractor license (1 year), professional engineer experience (1 year).
• Boiler Types & Construction – Fire-tube vs. water-tube, cast iron sectional, HRT (horizontal
return tubular), scotch marine, bent-tube, field-erected vs. package, electric boilers, waste heat
recovery.
• Steam Theory & Thermodynamics – Latent vs. sensible heat, steam quality (dryness fraction),
enthalpy, entropy, superheated steam, critical pressure.
• Boiler Safety Devices & Controls – Safety valve (ASME I), low-water cutoff (LWCO), pressure
controls, modulating combustion controls, flame safeguards (purge, ignition, flame detection),
blowback ring adjustment, feedwater regulators, gauge glass & water columns.
• Combustion Principles – Air-fuel ratio (excess air – 10-30% for gas/oil, 50% for pulverized coal),
primary/secondary air, combustion efficiency, flame stability, draft systems (natural,
mechanical, balanced).
• Water Treatment – Hardness (calcium, magnesium), scale vs. sludge, internal vs. external
treatment, blowdown (surface, bottom), pH control, oxygen scavengers (sodium sulfite),
phosphate treatment, chelants, deaeration.
• Boiler Operations & Procedures – Start-up, normal operation, shutdown, blowdown (bottom
blowdown at low load), warming up cold boiler (avoid thermal shock), hydrostatic test, lay-up
(wet vs. dry), cutting a boiler in/out of service.
• Auxiliary Equipment – Pumps (centrifugal, reciprocating, rotary), air compressors, deaerators
(remove oxygen), feedwater heaters, condensers, cooling towers, turbines, generators,
chillers/refrigeration.
• Electrical Systems – Single-phase vs. three-phase, motor types (AC/DC), fuses and breakers
(selection by load), basic motor control circuits, lockout/tagout (OSHA).
• Safety & OSHA – Confined space entry (permit, gas testing, PPE, rescue plan), lockout/tagout
(LOTO), PPE for boiler work, emergency shutdown, fire prevention (NFPA 54 fuel gas piping).
• Inspections & Maintenance – External inspection (once per shift), annual internal inspection,
LWCO/water column check (each shift), high-limit safety switch (annually), complete external
boiler inspection (once per shift), manhole clearance (5 ft minimum), overhead clearance for
package boilers (2 ft from ceiling).
QUESTION 1: A candidate for Maryland Grade 1 stationary engineer license has been working as a Grade
2 engineer under a Grade 1 for four years. He completed 12 credit hours of approved boiler safety CEUs.
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How many years of experience can he claim toward the required five years?
A) 4 years
B) 5 years
C) 6 years
D) 3 years
Answer: B – One year credit for six credit hours (12 hours = 2 years credit). 4 years actual + 2 years CEU
credit = 6 years total, but only 5 years are required; therefore meets the requirement with one year
excess .
QUESTION 2: What is the minimum horsepower threshold for a boiler to be regulated under the
Maryland Stationary Engineers Act, assuming it operates above 15 PSI?
A) 15 HP
B) 30 HP
C) 50 HP
D) 100 HP
Answer: B – The Act governs equipment operating at more than 15 PSI and 30 or more horsepower (or
1,003,000 Btu/hr steam equivalent) .
, Page 3 of 119
QUESTION 3: A Grade 1 stationary engineer is responsible for operating a plant with a single 600 HP
steam boiler. What is the highest horsepower plant a Grade 1 is qualified to oversee?
A) 299 HP
B) 499 HP
C) 500 HP or more
D) 1,000 HP maximum
Answer: C – A Grade 1 license authorizes operation of 500 or more horsepower equipment (in any
building) with no stated upper limit .
QUESTION 4: During a startup, a Grade 1 engineer opens the blowdown valves to warm the boiler. What
is the correct sequence for blowdown on a cold start?
A) Open fast to clear sediment
B) Crack the valve gently, then fully open for a few seconds
C) Blow down continuously for 5 minutes
D) Do not blow down until reaching full operating pressure
Answer: B – Cracking the valve gently prevents thermal shock; fully opening briefly removes sediment.
, Page 4 of 119
QUESTION 5: A fire-tube boiler is to be inspected for scale formation. Which area is most likely to
experience the heaviest scale buildup?
A) Steam drum
B) Water tubes
C) Heat transfer surfaces (tubes) on the water side
D) Superheater section
Answer: C – Scale forms where heat transfer is highest; in fire-tube boilers, the tube surfaces exposed to
hot gases on the outside and water on the inside.
QUESTION 6: An engineer notices that the boiler’s bottom blowdown line is leaking after a blowdown.
What is the immediate safety risk?
A) Loss of water level
B) Pressure drop
C) Reduced fuel efficiency
D) Corrosion only
Answer: A – A leaking bottom blowdown line can slowly drain the boiler water, leading to low water
condition and possible tube overheating.
