Boiler Maintenance, Inspection, and Repairs
What the exam tests
This domain covers inspection planning, condition assessment, code repairs, hydrostatic testing, and records. The National Board Inspection Code (NBIC) is central for repairs and alterations to ASME-stamped boilers, while the jurisdiction sets inspection intervals and inspector authority.
Core rules
- Internal and external inspections look for waterside corrosion, steam-side cracking, tube wastage, bulges, leak evidence, and deteriorated refractory or supports.
- Repairs to ASME-stamped items normally require an R-stamp holder, qualified welding procedure, qualified welders, and authorized inspector involvement.
- A hydrostatic test is a strength and leak test, not a substitute for visual internal inspection.
- Document repairs, materials, NDE, test pressure, and inspector sign-off. Keep the boiler history with the unit.
Worked example
A Section I boiler has MAWP 200 psig. The hydrostatic test pressure is 1.5 x 200 = 300 psig, subject to code rules and temperature correction. If someone proposes testing at 200 psig because that is the operating limit, the reasoning is wrong: the test is tied to MAWP, not normal operating pressure. If the boiler is repaired, the test follows the applicable code and inspector acceptance, not a shop guess.
Traps
Do not weld on a code boiler without the required stamp and procedure; do not use hydro testing to replace internal inspection; do not confuse operating pressure with MAWP; and do not ignore small tube leaks that may indicate widespread wastage.