API 510 Repair, Alteration & Rerating Procedures 2 — Questions and Answers
Question 1: According to API 510, who is responsible for ensuring that repair work on a pressure vessel meets the code requirements?
- The repair organization
- The pressure vessel owner/operator (Correct answer)
- The jurisdictional authority
- The original equipment manufacturer
Correct answer: The pressure vessel owner/operator
The owner/operator bears final responsibility for ensuring that all repair work complies with applicable code requirements.
Question 2: When a fillet weld repair is made to a pressure vessel shell, the minimum preheat temperature is generally determined by:
- The repair organization's standard procedure
- The original design pressure of the vessel
- The applicable welding code and material P-number (Correct answer)
- The jurisdiction's blanket requirement
Correct answer: The applicable welding code and material P-number
Preheat requirements are governed by the applicable welding code (such as ASME Section IX) based on the base metal's P-number and thickness.
Question 3: Under API 510, a 'major repair' to a pressure vessel typically requires:
- Only a post-repair hydrostatic test
- Prior approval and an authorized inspection before welding begins (Correct answer)
- Notification to the jurisdiction within 30 days after completion
- A written waiver from the original manufacturer
Correct answer: Prior approval and an authorized inspection before welding begins
Major repairs require prior approval from the inspector and often the jurisdiction, with the authorized inspector involved before and during welding.
Question 4: A pressure vessel is to be rerated to a higher MAWP. Which condition MUST be satisfied?
- The vessel must be less than 10 years old
- All welds must be radiographed regardless of original construction
- The vessel must be suitable for the new conditions based on current inspection data and calculations (Correct answer)
- The rerating must be approved by the original code committee
Correct answer: The vessel must be suitable for the new conditions based on current inspection data and calculations
Rerating to higher pressure requires engineering calculations and current inspection data confirming the vessel's fitness for the new service conditions.
Question 5: API 510 requires that alteration work on a pressure vessel be performed using which edition of the construction code?
- The edition in effect at the time of original construction
- Any edition selected by the repair organization
- The latest edition of the applicable code or the original edition (Correct answer)
- The edition specified by the jurisdictional authority only
Correct answer: The latest edition of the applicable code or the original edition
Alterations may be performed to the original code of construction or the latest applicable edition, per owner/operator and inspector agreement.
Question 6: After completing a repair involving welding on a pressure vessel, an 'R' stamp holder must:
- Conduct a metallurgical analysis of the weld
- Provide a written report to the National Board and owner/operator (Correct answer)
- Repaint the nameplate with the new repair date
- Submit radiographs to ASME for review
Correct answer: Provide a written report to the National Board and owner/operator
The R-stamp holder must submit a completed National Board Form R-1 (Report of Repair) to the owner/operator and jurisdictional authority.
Question 7: When installing a flush-type repair patch on a vessel shell, the patch corners should be:
- Cut at 90-degree angles for maximum strength
- Rounded with a minimum radius to reduce stress concentration (Correct answer)
- Beveled to a knife edge for full fusion
- Left square if the patch thickness is less than 0.5 inches
Correct answer: Rounded with a minimum radius to reduce stress concentration
Flush patch corners must be rounded with a minimum radius (typically ≥ 1 inch per NBIC) to minimize stress concentrations at the corners.
API 510 Repair, Alteration & Rerating Procedures 2
According to API 510, who is responsible for ensuring that repair work on a pressure vessel meets the code requirements?