NBIC Part 3 - Repairs and Alterations
Repair or alteration?
A repair restores an item to a safe condition consistent with its original design. An alteration changes something fundamental: pressure-retaining capability, design temperature, minimum design metal temperature, service fluid, or an appurtenance that affects pressure retention. Misclassifying the work invalidates every form that follows.
Rules
- Work is performed by an organization holding a National Board R Certificate of Authorization (VR for pressure relief devices).
- Welding follows a qualified WPS/PQR with performance-qualified welders per ASME Section IX; NDE and heat treatment follow the original code of construction.
- Repairs are documented on Form R-1; alterations on Form R-2, supported by design calculations from a qualified engineer and an updated or supplemental nameplate.
- The Inspector holds a National Board commission and is not employed by the repair organization; the inspector verifies material, procedures, qualifications, and tests before signing.
- A hydrostatic test at 1.5 × MAWP is normal where pressure integrity is affected; if impractical, alternative NDE with jurisdiction acceptance and written documentation.
- Routine maintenance - gaskets, refractory, external cleaning - is not a repair and does not require an R-1.
Worked example
A 2 in. nozzle is added to a Section VIII vessel shell. This is an alteration: it changes the pressure-retaining boundary. Reinforcement is calculated per UG-37, welding follows a qualified WPS, radiography follows UW-11, PWHT is checked against UCS-56 and impact requirements against the MDMT, the completed joint is hydro tested at 1.5 × MAWP, and Form R-2 with calculations goes to the owner and jurisdiction.
Traps
Calling an alteration a repair. Skipping the MDMT and impact check on new attachments. Waiving a hydro test without written justification. Forgetting the inspector must be independent of the R holder.