API 510 Repair and Alteration Standards 2 — Questions and Answers
Question 1: According to API 510, who must authorize a repair to a pressure vessel before work begins?
- The vessel owner/user (Correct answer)
- The repair organization alone
- The insurance company only
- The local fire marshal
Correct answer: The vessel owner/user
API 510 requires the owner/user to authorize repairs before the repair organization begins work.
Question 2: When welding repairs are made to a vessel that was originally post-weld heat treated (PWHT), what is generally required?
- PWHT of the repaired area (Correct answer)
- Hydrostatic test only, no PWHT needed
- Stress relief by cooling slowly in still air
- PWHT is never required for repairs
Correct 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.
Question 3: A 'temper bead' welding technique is primarily used to:
- Eliminate the need for PWHT by refining the heat-affected zone grain structure (Correct answer)
- Increase the hardness of the weld deposit
- Speed up the welding process for thick materials
- Reduce preheat requirements below code minimums
Correct 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.
Question 4: Under API 510, an alteration to a pressure vessel requires a new calculation or re-rating if:
- The change affects the vessel's pressure-containing capability or rated capacity (Correct answer)
- Any cosmetic modification is made to the exterior
- Only internal inspection is performed
- A nameplate is replaced with identical information
Correct 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.
Question 5: Which document must be completed and retained for alterations performed under the National Board Inspection Code (NBIC)?
- NB-3 form (Alteration Report) (Correct answer)
- R-1 form (Repair Data Report)
- ASME Form U-1 (Manufacturer's Data Report)
- API 653 Tank Repair Form
Correct answer: NB-3 form (Alteration Report)
The NB-3 form (Alteration Report) is required by the NBIC for alterations to pressure vessels.
Question 6: When a repair requires a weld on a vessel in hydrogen service, the primary concern for the filler metal selection is:
- Resistance to hydrogen-induced cracking and adequate strength (Correct answer)
- Lowest possible melting point for ease of welding
- Highest possible carbon content for hardness
- Color match with the base metal
Correct 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.
Question 7: A repair organization performing pressure vessel repairs must have a current:
- National Board 'R' Certificate of Authorization (Correct answer)
- API 510 inspector certification
- State boiler inspector license
- OSHA 30-hour safety card
Correct 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.
API 510 Repair and Alteration Standards 2
According to API 510, who must authorize a repair to a pressure vessel before work begins?