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Maryland Stationary Engineer Grade 2 Exam COMPLETE
QUESTIONS AND DETAILED SOLUTIONS LATEST
UPDATE THIS YEAR-JUST RELEASED
Maryland Stationary Engineer Grade 2 Exam,
Summarized Exam Topics Covered (Point Form – Accurate for MD Grade 2 Exam)
• Boiler Operation & Combustion: Water tube vs. fire tube, combustion efficiency, excess air,
draft (natural/mechanical), burners (atmospheric, power), flame safety controls
• Boiler Systems (Low/High Pressure): Steam and hot water boilers (15 psi steam, 160 psi water
for low pressure), feedwater systems, condensate return, blowdown (bottom/surface)
• Steam Traps: Float & thermostatic, inverted bucket, thermodynamic, thermostatic – function,
failure modes, troubleshooting
• Feedwater Treatment: Deaeration, chemical treatment (oxygen scavengers, pH control),
hardness removal, boiler water testing (TDS, pH, alkalinity)
• Pumps & Piping: Centrifugal, rotary, reciprocating – cavitation, NPSH, packing, mechanical seals,
affinity laws, pump curves
• Valves & Fittings: Gate, globe, check, ball, butterfly, pressure relief valves (ASME stamped),
temperature/pressure relief valves
• Water Treatment Programs: Internal vs. external, softening, reverse osmosis, dealkalization,
preventing scale and corrosion
• Water Column & Gauge Glass: Low water cutoff (LWCO – float, probe), gauge glass blowdown
procedure, high and low alarms
• Electrical & Controls: Motors (starters, overloads), VFDs, control loops (PID), transmitters
(pressure, temperature), actuators
• Energy Conservation & Efficiency: Stack temperature, O₂ trim, boiler staging, variable frequency
drives, economizers
• Combustion Analyzers: O₂, CO, CO₂, NOx, smoke spot test, draft gauge, tuning for efficiency
(10–15% excess air typical)
• Low Water Cutoff (LWCO) Testing: Blowdown test (at least weekly), verify burner shuts off
when water level drops
• Steam System Safety: Pressure relief valve testing (try lever every month, pop test every year),
proper valve sizing, discharge piping
• Heating Systems: Hot water boiler operation, circulators, expansion tanks (diaphragm,
compression), air elimination, pressure reducing valves
• ASME Code (Sections I, IV, VIII): Boiler construction (S stamp), repair (R stamp), pressure vessel
standards, nameplate requirements
• NFPA 85 (Boiler Combustion Controls): Flame safeguard programming, purge cycles (4–10 air
changes), trial for ignition (4–10 seconds)
• First Aid & Safety (NFPA 70E): Lockout/Tagout (LOTO), confined space entry (permit, gas
testing), PPE, SCBA, H₂S detection
• Facility Systems Overview: Chilled water systems (centrifugal, reciprocating chillers), cooling
towers, HVAC interface
• Preventive Maintenance: Log keeping, inspection intervals (ASME, NBIC), boiler
internal/external inspections
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• Start-Up & Shutdown Procedures: Light-off, warming up (avoid thermal shock), cool-down
procedures
• Troubleshooting: Flame failure, priming & foaming, carryover, surging water level, short cycling
• Calculations: Boiler horsepower (34.5 lb steam/hr = 33,475 Btu/hr), efficiency, fuel
consumption, pressure conversions (1 psi = 2.31 ft head, 27.7 in water)
• Codes & Standards: ASME Boiler and Pressure Vessel Code (B&PVC), NBIC (National Board
Inspection Code), NFPA 85, 54, 31, ASME CSD-1
1. A high-pressure steam boiler has a steady water level at normal load, but when the burner fires at
high fire, the water level drops sharply and then recovers. What is the most likely explanation for this
condition?
A) The feedwater pump is undersized for the boiler’s steaming rate
B) Shrink and swell effect – water level drops when load increases due to steam bubble collapse
C) The blowdown valve is leaking
D) The steam pressure gauge is reading incorrectly
Answer: B
Rationale: In a steam boiler, increasing the firing rate collapses steam bubbles in the water, causing an
immediate drop in water level (shrink). Conversely, a sudden load decrease causes swelling. This is a
normal phenomenon.
2. The low water cutoff (LWCO) on a fire tube steam boiler is tested by blowing down the water column.
The burner should shut off when the water level drops to the cutoff point. What is the frequency of this
test?
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A) Monthly
B) Every shift (daily) or at least weekly depending on local codes
C) Annually
D) Only after a boiler inspection
Answer: B
Rationale: Code requires that LWCO devices be tested regularly, typically at least daily while the boiler is
in service, to ensure they will shut down the burner if the water level drops dangerously low. This is a
critical safety test.
3. A technician is calibrating a combustion analyzer. The O₂ reading in the flue gas of a natural gas boiler
is 8%. What should the technician do to improve efficiency?
A) Close the air damper slightly to reduce excess air (target 3–6% O₂)
B) Open the air damper further to add more air
C) Increase the fuel gas pressure
D) Reduce the feedwater temperature
Answer: A
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Rationale: 8% O₂ is excessive excess air (dilution). Too much excess air wastes heat and lowers efficiency.
The technician should adjust the burner to achieve 3-6% O₂ (typical range).
4. A hot water boiler operates at 180°F. A sudden power failure occurs. What is the immediate risk to
the boiler?
A) The boiler will explode immediately
B) Thermal shock and possible tube cracking due to cold water entering the hot boiler when the system
restarts
C) The pressure relief valve will open
D) The expansion tank will rupture
Answer: B
Rationale: If the boiler is hot and the circulating pumps stop, cold makeup water entering the boiler upon
restart can cause severe thermal shock, cracking the boiler tubes or vessel. Proper cool-down procedures
are required.
5. Which code governs the construction of low-pressure heating boilers (ASME Section IV) and
high-pressure power boilers (ASME Section I)?
A) NFPA 70 (National Electrical Code)
Maryland Stationary Engineer Grade 2 Exam COMPLETE
QUESTIONS AND DETAILED SOLUTIONS LATEST
UPDATE THIS YEAR-JUST RELEASED
Maryland Stationary Engineer Grade 2 Exam,
Summarized Exam Topics Covered (Point Form – Accurate for MD Grade 2 Exam)
• Boiler Operation & Combustion: Water tube vs. fire tube, combustion efficiency, excess air,
draft (natural/mechanical), burners (atmospheric, power), flame safety controls
• Boiler Systems (Low/High Pressure): Steam and hot water boilers (15 psi steam, 160 psi water
for low pressure), feedwater systems, condensate return, blowdown (bottom/surface)
• Steam Traps: Float & thermostatic, inverted bucket, thermodynamic, thermostatic – function,
failure modes, troubleshooting
• Feedwater Treatment: Deaeration, chemical treatment (oxygen scavengers, pH control),
hardness removal, boiler water testing (TDS, pH, alkalinity)
• Pumps & Piping: Centrifugal, rotary, reciprocating – cavitation, NPSH, packing, mechanical seals,
affinity laws, pump curves
• Valves & Fittings: Gate, globe, check, ball, butterfly, pressure relief valves (ASME stamped),
temperature/pressure relief valves
• Water Treatment Programs: Internal vs. external, softening, reverse osmosis, dealkalization,
preventing scale and corrosion
• Water Column & Gauge Glass: Low water cutoff (LWCO – float, probe), gauge glass blowdown
procedure, high and low alarms
• Electrical & Controls: Motors (starters, overloads), VFDs, control loops (PID), transmitters
(pressure, temperature), actuators
• Energy Conservation & Efficiency: Stack temperature, O₂ trim, boiler staging, variable frequency
drives, economizers
• Combustion Analyzers: O₂, CO, CO₂, NOx, smoke spot test, draft gauge, tuning for efficiency
(10–15% excess air typical)
• Low Water Cutoff (LWCO) Testing: Blowdown test (at least weekly), verify burner shuts off
when water level drops
• Steam System Safety: Pressure relief valve testing (try lever every month, pop test every year),
proper valve sizing, discharge piping
• Heating Systems: Hot water boiler operation, circulators, expansion tanks (diaphragm,
compression), air elimination, pressure reducing valves
• ASME Code (Sections I, IV, VIII): Boiler construction (S stamp), repair (R stamp), pressure vessel
standards, nameplate requirements
• NFPA 85 (Boiler Combustion Controls): Flame safeguard programming, purge cycles (4–10 air
changes), trial for ignition (4–10 seconds)
• First Aid & Safety (NFPA 70E): Lockout/Tagout (LOTO), confined space entry (permit, gas
testing), PPE, SCBA, H₂S detection
• Facility Systems Overview: Chilled water systems (centrifugal, reciprocating chillers), cooling
towers, HVAC interface
• Preventive Maintenance: Log keeping, inspection intervals (ASME, NBIC), boiler
internal/external inspections
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• Start-Up & Shutdown Procedures: Light-off, warming up (avoid thermal shock), cool-down
procedures
• Troubleshooting: Flame failure, priming & foaming, carryover, surging water level, short cycling
• Calculations: Boiler horsepower (34.5 lb steam/hr = 33,475 Btu/hr), efficiency, fuel
consumption, pressure conversions (1 psi = 2.31 ft head, 27.7 in water)
• Codes & Standards: ASME Boiler and Pressure Vessel Code (B&PVC), NBIC (National Board
Inspection Code), NFPA 85, 54, 31, ASME CSD-1
1. A high-pressure steam boiler has a steady water level at normal load, but when the burner fires at
high fire, the water level drops sharply and then recovers. What is the most likely explanation for this
condition?
A) The feedwater pump is undersized for the boiler’s steaming rate
B) Shrink and swell effect – water level drops when load increases due to steam bubble collapse
C) The blowdown valve is leaking
D) The steam pressure gauge is reading incorrectly
Answer: B
Rationale: In a steam boiler, increasing the firing rate collapses steam bubbles in the water, causing an
immediate drop in water level (shrink). Conversely, a sudden load decrease causes swelling. This is a
normal phenomenon.
2. The low water cutoff (LWCO) on a fire tube steam boiler is tested by blowing down the water column.
The burner should shut off when the water level drops to the cutoff point. What is the frequency of this
test?
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A) Monthly
B) Every shift (daily) or at least weekly depending on local codes
C) Annually
D) Only after a boiler inspection
Answer: B
Rationale: Code requires that LWCO devices be tested regularly, typically at least daily while the boiler is
in service, to ensure they will shut down the burner if the water level drops dangerously low. This is a
critical safety test.
3. A technician is calibrating a combustion analyzer. The O₂ reading in the flue gas of a natural gas boiler
is 8%. What should the technician do to improve efficiency?
A) Close the air damper slightly to reduce excess air (target 3–6% O₂)
B) Open the air damper further to add more air
C) Increase the fuel gas pressure
D) Reduce the feedwater temperature
Answer: A
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Rationale: 8% O₂ is excessive excess air (dilution). Too much excess air wastes heat and lowers efficiency.
The technician should adjust the burner to achieve 3-6% O₂ (typical range).
4. A hot water boiler operates at 180°F. A sudden power failure occurs. What is the immediate risk to
the boiler?
A) The boiler will explode immediately
B) Thermal shock and possible tube cracking due to cold water entering the hot boiler when the system
restarts
C) The pressure relief valve will open
D) The expansion tank will rupture
Answer: B
Rationale: If the boiler is hot and the circulating pumps stop, cold makeup water entering the boiler upon
restart can cause severe thermal shock, cracking the boiler tubes or vessel. Proper cool-down procedures
are required.
5. Which code governs the construction of low-pressure heating boilers (ASME Section IV) and
high-pressure power boilers (ASME Section I)?
A) NFPA 70 (National Electrical Code)
