BLRS 6026 ROUTINE BOILER
MAINTENANCE AND INSPECTION
CHAPTER 12
Final Examination Questions & Answers with Verified Solutions
2026/2027
1. What primary safety step must be performed before opening any waterside manway
cover on a shutdown steam boiler?
A. Open the chemical feed line to flush residual drum solids
B. Verify drum temperature is cool, pressure reads zero, vacuum is broken, and
isolation valves are locked out
C. Start the forced draft fan to purge remaining fireside gases
D. Increase continuous blowdown flow to drain residual water rapidly
Rationale: Loosening manway bolts on a pressurized or vacuum-bound hot boiler creates severe burn
hazards and sudden gasket blowouts. Breaking vacuum and confirming zero pressure ensures safe drum
entry.
2. Which ASME code section provides recommended guidelines for the care,
maintenance, and routine inspection of power boilers?
A. ASME Section VII
B. ASME Section I
C. ASME Section IV
D. ASME Section VI
Rationale: ASME Section VII contains recommended guidelines for the safe care, operation, and routine
maintenance of power boilers. Section I covers construction rules, while Section VI covers heating boilers.
3. What operational test verifies that a float-type Low Water Fuel Cutoff (LWCO)
mechanism trips the burner during actual operation?
A. Hydrostatic pressure test
B. Slow drain test under active firing conditions
, C. Fast flush test of the gauge glass drain valve
D. Electrical continuity check across the terminal strip
Rationale: A slow drain test allows boiler water level to drop naturally while firing, proving that the float
moves freely down to isolate the burner safety shutoff valve at the required cutoff threshold.
4. What visual condition indicates severe caustic embrittlement along rolled tube joints
inside a steam drum?
A. Smooth uniform surface rusting
B. Fine intergranular spiderweb cracks radiating from rolled tube ends and rivet holes
C. Thick white calcium carbonate scale deposits
D. Heavy black magnetite pitting along the waterline
Rationale: Caustic embrittlement occurs when high sodium hydroxide concentrations pool in high-stress
zones like rolled joints, producing fine intergranular stress corrosion cracks.
5. What non-destructive examination (NDE) method is most effective for measuring
remaining wall thickness on corroded boiler tubes?
A. Liquid penetrant testing
B. Ultrasonic Thickness Testing (UT)
C. Magnetic particle testing
D. Visual inspection with a pit gauge
Rationale: Ultrasonic thickness gauges send high-frequency sound waves through tube walls, measuring
wave echo return time to determine remaining wall metal thickness accurately.
6. How often should power engineering operators perform a manual blowdown flush on a
float-type low water cutoff float chamber?
A. Annually during the annual boiler outage
B. Daily during active operating shifts
C. Monthly during water chemistry checks
D. Weekly during burner efficiency tuning
Rationale: Daily flushing clears sediment and sludge out of the float bowl, preventing floating debris from
jamming the mechanical linkage and causing low-water dry firing.
7. What chemical compound is used during a dry lay-up to absorb moisture inside an idle
, boiler drum?
A. Silica gel or quicklime (calcium oxide)
B. Sodium sulfite powder
C. Trisodium phosphate crystals
D. Caustic soda pellets
Rationale: Desiccants like silica gel or quicklime absorb ambient humidity inside sealed idle drums,
preventing condensation and oxygen corrosion during dry storage.
8. What layout condition requires a wet lay-up method instead of a dry lay-up for an idle
boiler?
A. The boiler will be offline for more than one year in sub-zero freezing weather
B. The boiler must be kept in standby readiness for rapid emergency startup within 24
to 48 hours
C. The boiler room lacks electrical power
D. The fireside refractory requires total brick replacement
Rationale: Wet lay-up keeps the waterside flooded with treated water, protecting metal surfaces from
oxygen while allowing quick pressure elevation during emergency demand.
9. What defect occurs when soot is allowed to remain on fireside tube surfaces during a
prolonged outage in humid conditions?
A. High thermal expansion stress
B. Severe sulfurous acid corrosion (acid attack) beneath moist soot deposits
C. Caustic gouging along tube seats
D. Graphitic softening of refractory brick
Rationale: Soot contains sulfur compounds from combustion products. Humidity turns sulfur residue into
corrosive sulfurous and sulfuric acids that eat tube steel.
10. What test pressure is applied during a standard routine maintenance hydrostatic test
on an existing in-service boiler?
A. 1.25 times Maximum Allowable Working Pressure (MAWP) or 1.0 times MAWP per
NBIC guidelines
B. 2.5 times operating pressure
C. 1.5 times safety valve set pressure
MAINTENANCE AND INSPECTION
CHAPTER 12
Final Examination Questions & Answers with Verified Solutions
2026/2027
1. What primary safety step must be performed before opening any waterside manway
cover on a shutdown steam boiler?
A. Open the chemical feed line to flush residual drum solids
B. Verify drum temperature is cool, pressure reads zero, vacuum is broken, and
isolation valves are locked out
C. Start the forced draft fan to purge remaining fireside gases
D. Increase continuous blowdown flow to drain residual water rapidly
Rationale: Loosening manway bolts on a pressurized or vacuum-bound hot boiler creates severe burn
hazards and sudden gasket blowouts. Breaking vacuum and confirming zero pressure ensures safe drum
entry.
2. Which ASME code section provides recommended guidelines for the care,
maintenance, and routine inspection of power boilers?
A. ASME Section VII
B. ASME Section I
C. ASME Section IV
D. ASME Section VI
Rationale: ASME Section VII contains recommended guidelines for the safe care, operation, and routine
maintenance of power boilers. Section I covers construction rules, while Section VI covers heating boilers.
3. What operational test verifies that a float-type Low Water Fuel Cutoff (LWCO)
mechanism trips the burner during actual operation?
A. Hydrostatic pressure test
B. Slow drain test under active firing conditions
, C. Fast flush test of the gauge glass drain valve
D. Electrical continuity check across the terminal strip
Rationale: A slow drain test allows boiler water level to drop naturally while firing, proving that the float
moves freely down to isolate the burner safety shutoff valve at the required cutoff threshold.
4. What visual condition indicates severe caustic embrittlement along rolled tube joints
inside a steam drum?
A. Smooth uniform surface rusting
B. Fine intergranular spiderweb cracks radiating from rolled tube ends and rivet holes
C. Thick white calcium carbonate scale deposits
D. Heavy black magnetite pitting along the waterline
Rationale: Caustic embrittlement occurs when high sodium hydroxide concentrations pool in high-stress
zones like rolled joints, producing fine intergranular stress corrosion cracks.
5. What non-destructive examination (NDE) method is most effective for measuring
remaining wall thickness on corroded boiler tubes?
A. Liquid penetrant testing
B. Ultrasonic Thickness Testing (UT)
C. Magnetic particle testing
D. Visual inspection with a pit gauge
Rationale: Ultrasonic thickness gauges send high-frequency sound waves through tube walls, measuring
wave echo return time to determine remaining wall metal thickness accurately.
6. How often should power engineering operators perform a manual blowdown flush on a
float-type low water cutoff float chamber?
A. Annually during the annual boiler outage
B. Daily during active operating shifts
C. Monthly during water chemistry checks
D. Weekly during burner efficiency tuning
Rationale: Daily flushing clears sediment and sludge out of the float bowl, preventing floating debris from
jamming the mechanical linkage and causing low-water dry firing.
7. What chemical compound is used during a dry lay-up to absorb moisture inside an idle
, boiler drum?
A. Silica gel or quicklime (calcium oxide)
B. Sodium sulfite powder
C. Trisodium phosphate crystals
D. Caustic soda pellets
Rationale: Desiccants like silica gel or quicklime absorb ambient humidity inside sealed idle drums,
preventing condensation and oxygen corrosion during dry storage.
8. What layout condition requires a wet lay-up method instead of a dry lay-up for an idle
boiler?
A. The boiler will be offline for more than one year in sub-zero freezing weather
B. The boiler must be kept in standby readiness for rapid emergency startup within 24
to 48 hours
C. The boiler room lacks electrical power
D. The fireside refractory requires total brick replacement
Rationale: Wet lay-up keeps the waterside flooded with treated water, protecting metal surfaces from
oxygen while allowing quick pressure elevation during emergency demand.
9. What defect occurs when soot is allowed to remain on fireside tube surfaces during a
prolonged outage in humid conditions?
A. High thermal expansion stress
B. Severe sulfurous acid corrosion (acid attack) beneath moist soot deposits
C. Caustic gouging along tube seats
D. Graphitic softening of refractory brick
Rationale: Soot contains sulfur compounds from combustion products. Humidity turns sulfur residue into
corrosive sulfurous and sulfuric acids that eat tube steel.
10. What test pressure is applied during a standard routine maintenance hydrostatic test
on an existing in-service boiler?
A. 1.25 times Maximum Allowable Working Pressure (MAWP) or 1.0 times MAWP per
NBIC guidelines
B. 2.5 times operating pressure
C. 1.5 times safety valve set pressure
