Repair and Alteration Standards Flashcards

According to API 510, who must authorize a repair to a pressure vessel before work begins?

Answer: The vessel owner/user

API 510 requires the owner/user to authorize repairs before the repair organization begins work.

When welding repairs are made to a vessel that was originally post-weld heat treated (PWHT), what is generally required?

Answer: PWHT of the repaired area

When the original fabrication required PWHT, repairs involving welding typically require PWHT of the repaired area unless an exemption applies.

A 'temper bead' welding technique is primarily used to:

Answer: Eliminate the need for PWHT by refining the heat-affected zone grain structure

Temper bead welding uses successive weld beads to refine and temper the HAZ, allowing PWHT to be waived under specific conditions.

Under API 510, an alteration to a pressure vessel requires a new calculation or re-rating if:

Answer: The change affects the vessel's pressure-containing capability or rated capacity

Alterations that affect the pressure-containing capability require engineering calculations and possible re-rating.

Which document must be completed and retained for alterations performed under the National Board Inspection Code (NBIC)?

Answer: NB-3 form (Alteration Report)

The NB-3 form (Alteration Report) is required by the NBIC for alterations to pressure vessels.

When a repair requires a weld on a vessel in hydrogen service, the primary concern for the filler metal selection is:

Answer: Resistance to hydrogen-induced cracking and adequate strength

Hydrogen service requires filler metals selected for resistance to hydrogen-induced cracking, often requiring low-hydrogen processes.

A repair organization performing pressure vessel repairs must have a current:

Answer: National Board 'R' Certificate of Authorization

Repair organizations must hold a current National Board 'R' Certificate of Authorization to perform NBIC-covered pressure vessel repairs.