API 510 Repair, Alteration & Rerating Procedures — Questions and Answers
Question 1: What is the main objective of a repair procedure on a pressure vessel?
- To enhance the aesthetic appeal.
- To ensure the vessel meets minimum wall thickness requirements (Correct answer)
- To modify the operating fluid.
- To increase the vessel weight.
Correct answer: To ensure the vessel meets minimum wall thickness requirements
The primary objective of a repair procedure on a pressure vessel is to restore its structural integrity and ensure it can safely operate within its design parameters. This often involves addressing corrosion or damage to bring the vessel back to or above its minimum required wall thickness.
Question 2: Which code governs the repair and alteration of pressure vessels?
- ASME Section II.
- OSHA Standard 1910.
- NBIC (Correct answer)
- ANSI B31.1
Correct answer: NBIC
The National Board Inspection Code (NBIC) is the recognized standard that governs the repair, alteration, and rerating of pressure-retaining items, including pressure vessels. API 510 inspectors must be familiar with NBIC requirements for these activities.
Question 3: What must be done before rerating a pressure vessel?
- Change the insulation material.
- Apply a new paint coating.
- Conduct engineering calculations and obtain authorization (Correct answer)
- Replace the pressure relief valve only.
Correct answer: Conduct engineering calculations and obtain authorization
Rerating a pressure vessel involves changing its maximum allowable working pressure (MAWP) or temperature. This significant change requires thorough engineering calculations to confirm the vessel's suitability for the new conditions, followed by authorization from an authorized inspector.
Question 4: Who must authorize repairs on a pressure vessel?
- The plant operator.
- The design engineer.
- An authorized inspector (Correct answer)
- The cleaning crew supervisor.
Correct answer: An authorized inspector
According to API 510 and NBIC, all repairs and alterations to pressure vessels must be authorized by an authorized inspector before work commences. This ensures that the repair plan meets code requirements and maintains the vessel's integrity and safety.
Question 5: When is rerating of a vessel required?
- During annual painting.
- When increasing the pressure or temperature rating (Correct answer)
- When changing operators.
- After cleaning the vessel.
Correct answer: When increasing the pressure or temperature rating
Rerating is specifically required when an owner/user wishes to change the design conditions of a pressure vessel, such as increasing its maximum allowable working pressure (MAWP) or design temperature. This process ensures the vessel remains safe and compliant under the new operating parameters.
Question 6: What is typically required after a major alteration on a vessel?
- A change in vendor.
- Only a visual inspection.
- A pressure test and authorized inspection (Correct answer)
- An insurance review.
Correct answer: A pressure test and authorized inspection
Major alterations significantly change a vessel's design or integrity. To ensure the vessel's continued safety and compliance, a pressure test (e.g., hydrostatic or pneumatic) is typically required after such an alteration, along with a final inspection and acceptance by an authorized inspector.
Question 7: What document records the details of a repair?
- A marketing flyer.
- An NBIC Repair Form R-1 (Correct answer)
- A material test report.
- A quality survey.
Correct answer: An NBIC Repair Form R-1
The NBIC Repair Form R-1 is a standardized document used to record details of repairs and alterations performed on pressure-retaining items. It provides a comprehensive record of the work done, materials used, and inspections performed, ensuring traceability and compliance with code requirements.
Question 8: What is the role of a repair organization?
- To design new vessels.
- To operate the plant.
- To perform authorized vessel repairs (Correct answer)
- To conduct financial audits.
Correct answer: To perform authorized vessel repairs
A repair organization, often holding an R-stamp from the National Board, is specifically qualified and authorized to perform repairs and alterations on pressure vessels and other pressure-retaining items. Their role is to execute these repairs in accordance with applicable codes and standards.
Question 9: How should alterations be handled on coded vessels?
- By skipping documentation.
- According to NBIC with inspector approval (Correct answer)
- By changing the asset tag.
- Using outdated blueprints.
Correct answer: According to NBIC with inspector approval
Alterations on coded pressure vessels are significant modifications that must strictly adhere to the National Board Inspection Code (NBIC) requirements. This includes detailed engineering review, proper documentation, and mandatory approval by an authorized inspector to ensure the vessel's continued safety and code compliance.
API 510 Repair, Alteration & Rerating Procedures
What is the main objective of a repair procedure on a pressure vessel?