Maryland Law: Editorial Revision Group
Not publishedof exam
Grade Horsepower ThresholdsAttendance & Monitoring RulesExam, Renewal & Inspection LawLargest Single Unit Rule
Boilers, Valves & Safety Controls
Not publishedof exam
Boiler Types & ASME CodesSafety Valves & Gauge GlassLow-Water Cutoff & ControlsPumps & Steam Header Valves
Burners, Combustion & Emergencies
Not publishedof exam
Combustion, Draft & PurgeFlame Safeguard SequenceSequential & Emergency OperationsLow-Water vs Tube Rupture
Water Treatment & Blowdown
Not publishedof exam
Scale, Sludge & CarryoverDeaeration & Chemical TreatmentBottom vs Surface BlowdownZeolite Softener Limits
Auxiliaries, Chillers & Electricity
Not publishedof exam
Condensers, NPSH & PumpsChillers & Refrigeration CycleBasic DC & AC ElectricityMotor Overload Protection
Quick Facts
- Licensing Board
- Maryland Board of Stationary Engineers
- Exam Delivery
- PSI; qualification approval before scheduling
- Scored Outline Count
- G5–G4: 60; G3–G1: 80
- Possible Additional Items
- 5–10 experimental, unscored; extra time
- Answering Time
- 120 minutes for scored examination
- Passing Score
- 70%: 42/60 or 56/80
- Book Policy
- G5–G4 approved open-book; G3–G1 closed-book
- Licence Term
- Normally two years; statutory stagger exception
- Revision Filters
- Five editorial groups; official outlines separate
Maryland 5-Grade Horsepower Ladder
30-99 G5/G4, 100-299 G3, 300-499 G2, 500+ G1
G5: 30-99 HP non-publicG4: 30-99 HP any buildingG3: 100-299; G2: 300-499; G1: 500+
Grades 5–4 vs Grades 3–1 PSI Exams
Grades 5 & 4
- 60 scored-outline items; 120 minutes
- Open book (approved references)
- Need 42 correct (70%)
Grades 3, 2 & 1
- 80 scored-outline items; 120 minutes
- Closed book examination
- Need 56 correct (70%)
60 open-book vs 80 closed-book
Maryland License Grade Picker
- Statutory heating-boiler definition applies→Stationary-service licensing definition excludes heating boilers(Inspection obligations are a separate question)
- Hot-water statutory heating definition→Pressure ≤160 psig OR temperature ≤250°F(Statutory OR; distinct from ASME shorthand)
- 30-99 HP in non-public building→Grade 5 Stationary Engineer
- 30-99 HP in public building→Grade 4 Stationary Engineer
- Largest single unit 100-299 HP→Grade 3 Stationary Engineer
- Largest single unit 300-499 HP→Grade 2; 500+ HP Grade 1
2-Year Power Boiler Inspection Extension
Board may extend certificate interval; conditions must all qualify
Power boiler; Board-approved extension onlyContinuous internal treatment; experienced PE supervisesOutage date, time and reason recordsWater analyses: ≤48 operating-hour intervalsAnnual external inspection remains separate
COMAR 09.17 Alarm vs Shutdown Picker
- High stack flue gas temperature→Sound alarm AND shut burner
- Steam high-pressure or low/high-water condition→Specified monitoring alarm and automatic shutdown
- Low steam pressure or burner off→Alarm required; shutdown follows applicable safeguards(Not shutdown triggers under section .07)
- Boiler shuts down automatically→Licensee/designee physically inspects before restart(Qualifying system shutdown under section .07)
Attendance: Qualified Monitoring Exceptions
- G5, No Qualified Monitoring
- Visit every 24 operating hours minimum
- G4 Public, No Monitoring
- Attend continuously; special school rule applies
- G4 School, No Monitoring
- School hours; other hours ≥150 occupants
- G5, Qualified Monitoring
- Weekly visit; 24-hour availability; daily log
- G4–G1 Monitored Public
- Visit every eight open hours minimum
- G3–G1 Monitored Non-Public
- Scheduled visits not required; duties remain
- Qualifying Monitoring
- 24-hour computerized monitoring plus automatic controls
- 300 HP or More
- Monitor, indicate AND record specified points
- Qualifying Shutdown Manual Reset
- Licensee/designee physically inspects before restart
- Monitored School G4 Exception
- School-hours/≥150-occupant condition still applies
- All Monitored Attendance Exceptions
- Responsibility, 24-hour availability, daily log remain
Exam, Renewal & Inspection Law
- G5-G4 Pass Mark
- 42 of 60 items correct70%
- G3-G1 Pass Mark
- 56 of 80 items correct70%
- Board FAQ: Reapply After Failure
- First 30 days; subsequent requests 60
- PSI Registration Validity
- 90 days; fee nonrefundable, nontransferable
- Score Validity
- Apply for license within 2 years
- Expired > 24 Months
- Non-renewable; must retest
- Covered Power Boiler Inspections
- Annual inspections; approved certificate extension possible
- Accident Notice
- Notify Chief Inspector within 24h
- Unauthorized Material During Examination
- Reject application; reexamination barred ≥1 year
PSI Outline Counts: Part 1
- General knowledge and problem solving
- G5–4: 20; G3: 10; G2–1: 5
- Basic electricity
- G5–4: 5; G3: 5; G2–1: 5
- Boiler types and equipment
- G5–4: 5; G3: 10; G2–1: 5
- Burners and fuel train
- G5–4: 5; G3: 10; G2–1: 10
- Pumps and valves
- G5–4: 5; G3: 10; G2–1: 10
- Sequential operations
- G5–4: 0; G3: 10; G2–1: 10
PSI Outline Counts: Part 2
- Inspections and maintenance
- G5–4: 5; G3: 5; G2–1: 10
- Central station and chillers
- G5–4: 0; G3: 5; G2–1: 5
- Water treatment
- G5–4: 5; G3: 5; G2–1: 10
- Emergency operations
- G5–4: 5; G3: 5; G2–1: 5
- Auxiliary equipment
- G5–4: 5; G3: 5; G2–1: 5
Firetube vs Watertube Boilers
Firetube Boiler
- Hot gases pass inside tubes
- Large water volume, slower response
- Often lower duty; design ratings govern
Watertube Boiler
- Water circulates inside the tubes
- Often faster response; design-dependent
- Handles high pressures and loads
Gas in tubes vs water
Boiler Types, ASME & Fittings
- ASME Section I
- Power-boiler construction; steam above 15 psig
- ASME Section IV
- Heating-boiler construction; applicable limits and edition
- ASME Section VIII
- Pressure-vessel construction; scope and exclusions apply
- MAWP and Valve Settings
- At least one valve ≤MAWPPower boiler, COMAR .24G
- Safety Valve Rule
- Direct connection; no shutoff valve
- Try-Lever Test
- Movement check, not set-pressure calibration
- Water Column
- Dampens surges; test per approved procedure
- Non-Return Valve
- Prevents backflow when boiler pressure drops
- Existing Power Boiler Additional Valves
- Settings ≤103% MAWP; full conditions apply
Operating Control vs High-Limit Control
Operating Control
- Cycles or modulates burner daily
- Holds normal operating pressure
- Normal cycling follows control design
High-Limit Control
- Independent protective limit on unsafe conditions
- Setting coordinated with approved relief protection
- Reset mode follows applicable code/design
Normal cycling vs safety lockout
Three Ts of Complete Combustion
Temperature, Turbulence, and Time with right oxygen
Temperature: ignite fuelTurbulence: mix air-fuelTime: burn before tubes
Low-Water Emergency vs Tube Rupture
Low-Water Condition
- Secure heat input under emergency procedure
- Dry/overheated boiler: no water addition
- Inspect and obtain authorized restart clearance
Tube Rupture
- Secure heat input under emergency procedure
- Feedwater decision depends on boiler condition
- Isolation follows equipment-specific approved procedure
Overheating risk vs rupture-specific response
Boiler Emergency Action Picker
- Low water; dry/overheated boiler suspected→Secure heat input; no water addition(Approved shutdown and inspection before restart)
- Boiler tube ruptures on line→Approved emergency shutdown; keep personnel clear(Condition/equipment determine feedwater and isolation)
- Safety valve lifts repeatedly→Prevent overpressure; investigate controls through procedure(Never gag or obstruct relief)
- Burner trips on flame failure→Investigate cause; approved purge before restart(No repeated blind resets)
- Boiler accident or explosion occurs→Notify Chief Inspector within 24h
Burners, Draft & Flame Safeguard
- 3 Ts of Combustion
- Temperature, turbulence, and time
- Complete Hydrocarbon Combustion
- CO₂ and water; other products possible
- Incomplete Sign
- Carbon monoxide, smoke, or soot
- Forced Draft
- Fan pushes air toward combustion chamber
- Induced Draft
- Fan draws combustion gases toward stack
- Balanced Draft
- Both fans; controlled furnace pressure
- Pre-Purge / Post-Purge
- Prescribed airflow clears accumulated combustibles
- Flame Scanner
- Flame-safeguard system trips fuel upon failure
Bottom Blowdown vs Surface Blowdown
Bottom Blowdown
- Drawn from lowest mud drum
- Short, intermittent valve operation
- Removes settled sludge solids
Surface Blowdown
- Skims just below water line
- Metered continuous or intermittent design
- Controls total dissolved solids (TDS)
Settled sludge vs surface TDS
Water Problems: Treatment-Plan Decisions
- TDS exceeds approved treatment-plan limit→Adjust blowdown under the approved plan(No universal valve opening or flow)
- Sludge settles in mud drum→Approved intermittent bottom-blowdown procedure
- Calcium and magnesium hardness present→Verify softener and approved treatment plan
- Dissolved oxygen causing tube pitting→Check deaeration and prescribed scavenger treatment(Qualified treatment specialist sets chemical dose)
Water Treatment & Blowdown
- Scale
- Hard deposits; hardness often contributes
- Sludge
- Loose settled suspended solids
- Dissolved Oxygen
- Causes localized tube metal pitting
- Deaerator
- Heats and vents non-condensable gases
- Oxygen Scavenger
- Chemically removes residual dissolved O2
- Zeolite Softener
- Swaps Ca/Mg ions for sodium
- Bottom Blowdown
- Short intermittent removal of sludge
- Surface Blowdown
- TDS control; continuous or intermittent design
Four-Step Refrigeration Cycle Order
Compressor, Condenser, Expansion device, Evaporator in loop
Compressor: raises P and TCondenser: rejects heatExpansion drops P; Evaporator cools
Centrifugal vs Positive Displacement Pump
Centrifugal Pump
- Uses rotating impeller velocity
- Flow drops as pressure rises
- Closed discharge can overheat; follow manufacturer
Positive Displacement
- Moves fixed volume per stroke
- Builds destructive pressure if blocked
- Protect blocked discharge with approved relief
Variable flow vs fixed displacement
Auxiliaries, Pumps & Chillers
- Elevated Deaerator
- Provides NPSH to feed pump
- Cavitation
- Vapor bubbles form, then collapse
- Surface Condenser
- Condenses exhaust; supports turbine vacuum
- Economizer
- Preheats feedwater using flue gas
- Compressor
- Raises refrigerant pressure and temperature
- Condenser (Chiller)
- Rejects heat, liquefies refrigerant
- Expansion Device
- Throttles pressure; refrigerant partly flashes
- Evaporator
- Absorbs heat from building load
Basic Electricity & Motor Controls
- Ohm's Law
- Volts equal amps times ohmsE = I × R
- DC Electric Power
- Watts equal volts times ampsP = E × I; DC
- Series Circuit
- Same current; voltages add up
- Parallel Circuit
- Same voltage; branch currents add
- Motor Overload
- Protects windings from sustained overcurrent
- Fuses / Breakers
- Protect against short-circuit faults
- Lockout / Tagout
- Isolate, lock, control stored energy, verify
- AC Real Power
- Single-phase: V × I × power-factor
Common Traps
Single-Unit Capacity vs Plant Capacity
Licence grade: largest individual regulated unit ≠ Plant total: not the grade calculation
Engineer Licensing vs Equipment Inspection
Title 6.5: engineer grades and attendance ≠ Title 12-9: equipment inspection and certificates
Routine Feedwater vs Overheated Dry Boiler
Normal operation: maintain approved water level ≠ Overheated dry boiler: no water addition
Gauge Indication vs Verified Water Level
Motionless glass: potentially obstructed, not proof ≠ Approved verification: investigate uncertain water level
Softening vs Deaeration
Softener: exchanges calcium and magnesium ions ≠ Deaerator: heats and removes dissolved gases
Ordinary Reciprocity vs Military Recognition
Ordinary route: no out-of-state reciprocity ≠ Qualified military relocation: separate recognition provisions
Last Minute
- 1.Trigger: >15 psi AND ≥30 HP
- 2.Heating boilers: excluded from licensing definition
- 3.Grade: largest single regulated unit
- 4.Pass: 70% (42/60; 56/80)
- 5.G5–4: approved open-book; G3–1: closed-book
- 6.Reapplication: first 30 days; subsequent 60
- 7.Power certificate extension: Board-approved, not automatic
- 8.Required certification: display licence with photograph
- 9.Identification: valid government-issued photo ID available
- 10.Boiler accident notice: within 24 hours
- 11.Safety relief: no intervening shutoff valve
- 12.Dry/overheated boiler: no water addition
- 13.Steam admission: equipment-specific approved pressure sequence
- 14.Qualifying manual reset: physical inspection first
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