API 510 Repair and Alteration 4 — Questions and Answers
Question 1: What is the primary purpose of a fitness-for-service (FFS) assessment in the context of API 510 repair decisions?
- To determine if the vessel is worth the cost to repair
- To evaluate whether a vessel with a flaw can continue operating safely without immediate repair (Correct answer)
- To certify the repair organization's competency
- To establish a new inspection interval after repair
Correct answer: To evaluate whether a vessel with a flaw can continue operating safely without immediate repair
FFS assessments per API 579 evaluate whether a vessel with identified flaws can continue safe operation, potentially avoiding costly immediate repairs.
Question 2: Under API 510, a rerating that decreases the MAWP of a pressure vessel:
- Always requires an authorized pressure vessel inspector and engineering approval (Correct answer)
- Can be done by the operator without documentation
- Only requires a new nameplate with the lower pressure
- Requires National Board approval before implementation
Correct answer: Always requires an authorized pressure vessel inspector and engineering approval
All reratings, whether increasing or decreasing MAWP, require authorized inspector review and appropriate engineering documentation per API 510.
Question 3: A weld repair procedure must be qualified per which standard before being used on a pressure vessel?
- API 510 Appendix A
- ASME Section IX (Correct answer)
- ASME Section VIII Division 1
- NBIC Part 3
Correct answer: ASME Section IX
Weld procedure qualifications for pressure vessel repairs must be performed and documented in accordance with ASME Section IX.
Question 4: When planning a repair on a vessel with stress corrosion cracking (SCC), the most important first step is to:
- Begin welding immediately to seal the cracks
- Identify and eliminate the cause of the SCC before repairing (Correct answer)
- Perform a hydrostatic test to confirm crack locations
- Apply a corrosion inhibitor to the affected area
Correct answer: Identify and eliminate the cause of the SCC before repairing
Repairing SCC without addressing the root cause will result in recurrence; the causative agent or condition must be identified and eliminated first.
Question 5: According to API 510, non-pressure-bearing attachments welded to a pressure vessel are:
- Not subject to any inspection requirements
- Subject to the same inspection requirements as pressure welds (Correct answer)
- Considered repairs only if they exceed 6 inches in length
- Subject to inspection only if they are structural supports
Correct answer: Subject to the same inspection requirements as pressure welds
Non-pressure-bearing attachments welded to pressure vessels are subject to inspection requirements because improper welding can introduce flaws into the pressure boundary.
Question 6: A vessel that has undergone a significant repair must have an updated inspection record that includes which of the following?
- Only the date of repair and name of the repair organization
- Details of repair procedures, materials, NDE results, and inspector certification (Correct answer)
- A photograph of the completed repair only
- The estimated remaining life calculation only
Correct answer: Details of repair procedures, materials, NDE results, and inspector certification
API 510 requires comprehensive documentation of all repair details including procedures, materials, NDE results, and inspector certification to maintain traceability.
Question 7: When a corroded area of a vessel shell is repaired using a weld buildup, the deposited weld metal must have mechanical properties:
- Exactly matching the original base metal
- Equal to or greater than the minimum specified for the base metal (Correct answer)
- At least 10% greater than the original base metal
- As specified by the repair organization's QC manual
Correct answer: Equal to or greater than the minimum specified for the base metal
Weld filler metals must provide mechanical properties equal to or exceeding the minimum specified for the base metal being repaired.
API 510 Repair and Alteration 4
What is the primary purpose of a fitness-for-service (FFS) assessment in the context of API 510 repair decisions?