Inspection, Repairs, and Alterations
This domain tests NBIC Part 3: classifying work as a repair or alteration, controlling welding and NDE, using the R Certificate of Authorization, and documenting the work so the item can be returned to service lawfully.
Repair versus alteration
A repair restores a pressure-retaining item to a safe condition without changing its design. Examples: weld buildup of corroded areas, tube replacement, seal welding a leak, or replacing a section of shell with equivalent material. An alteration changes design pressure, design temperature, service fluid, dimensions, or adds a nozzle that changes the design. Rerating is always an alteration.
Controls
Repairs and alterations must be performed by an organization holding a valid R Certificate of Authorization, unless the jurisdiction has a written exception. Welding requires a qualified WPS, procedure qualification, welder performance qualification, and any required preheat or postweld heat treatment. NDE personnel must be qualified to the applicable standard. The Authorized Inspector reviews the work at required hold points and signs the report.
Worked example
A vessel owner wants to add a 2-inch nozzle to a shell. This is an alteration, not a repair: it changes the design configuration. The R stamp holder prepares design calculations, selects qualified welding and NDE, obtains AI approval before covering the weld, and completes the alteration report. The nameplate or supplemental nameplate is updated as required. If the owner instead replaced a corroded nozzle neck with an identical one, that is a repair.
Traps
Calling a rerating a repair. Skipping AI hold points. Using an unqualified welder or an unapproved WPS. Ignoring minimum design metal temperature when selecting material. Failing to update records and nameplate data.