API 510 Repair and Alteration 2 — Questions and Answers
Question 1: When welding a repair patch onto a pressure vessel, the minimum preheat temperature is determined primarily by:
- The vessel's operating pressure
- The base metal P-number and thickness (Correct answer)
- The type of filler metal used
- The inspector's discretion
Correct answer: The base metal P-number and thickness
Preheat requirements per API 510 and ASME Section IX are governed by the base metal P-number and thickness.
Question 2: A vessel owner wants to add a new nozzle to an existing pressure vessel. Under API 510, this would be classified as:
- A routine repair
- An alteration (Correct answer)
- A minor modification
- A rerating
Correct answer: An alteration
Adding a nozzle changes the vessel's design configuration and is classified as an alteration under API 510.
Question 3: After completing a weld repair on a pressure vessel, post-weld heat treatment (PWHT) is required when:
- The repair weld is longer than 12 inches
- The original code of construction required PWHT or the repair weld exceeds thickness thresholds (Correct answer)
- Any fillet weld is used in the repair
- The vessel operates above 150°F
Correct answer: The original code of construction required PWHT or the repair weld exceeds thickness thresholds
PWHT is required after repairs when the original code of construction mandated it or when the repair weld thickness exceeds code-specified thresholds.
Question 4: A repair organization completing work on a pressure vessel in the field must have which of the following?
- An NB-23 National Board Inspection Code certificate
- An R-stamp from the National Board of Boiler and Pressure Vessel Inspectors (Correct answer)
- An API 510 certification
- A state-issued pressure vessel repair license
Correct answer: An R-stamp from the National Board of Boiler and Pressure Vessel Inspectors
The R-stamp from the National Board certifies that the repair organization has a quality control system for pressure vessel repairs.
Question 5: Which document must be prepared by the repair organization and filed with the National Board after completing an alteration to a pressure vessel?
- Form R-1 (Correct answer)
- Form NB-7
- Form API-110
- Form VR-1
Correct answer: Form R-1
Form R-1 (Report of Repair or Alteration) must be prepared and filed with the National Board after alterations to pressure vessels.
Question 6: Under API 510, who has the authority to approve a repair or alteration on a pressure vessel?
- The plant engineer of record
- The repair organization alone
- The authorized pressure vessel inspector (Correct answer)
- The original equipment manufacturer
Correct answer: The authorized pressure vessel inspector
The authorized pressure vessel inspector must review and approve repairs and alterations before work begins and must inspect the work.
Question 7: A temporary repair using a fillet-welded box patch on a pressure vessel shell is:
- Never permitted under API 510
- Permitted with owner/user and inspector approval as a temporary measure (Correct answer)
- Permitted only if the vessel is retired within 30 days
- Permitted without documentation if below 150 psi
Correct answer: Permitted with owner/user and inspector approval as a temporary measure
API 510 allows temporary repairs such as fillet-welded box patches with documented owner/user and inspector approval until a permanent repair is made.
API 510 Repair and Alteration 2
When welding a repair patch onto a pressure vessel, the minimum preheat temperature is determined primarily by: