The requirements for revalidation will be:
1. Obtain a copy of ISO 15156 (all parts, not just Part 1)
2. Read aforementioned documents
3. Confirm that the vessel owner has consented to the application of the stipulated permitted exclusions where allowed, if not, move to 4.
4. Thoroughly review manufacturing records of the vessel
5. Ascertain that all pertinent materials, and welds, meet the requirements of the documents, paying special attention to clause 8 of Part 2, if not, move to 6
6. If the manufacturing records are non-compliant, think of ways to make them compliant; naturally, forgery is not a recommended option (again, watch out for Part 2, Clause 8 because it is well tricksy)
7. If the records are absent, sit down and think what non-destructive tests could bring the materials into compliance
8. Execute such tests
9. Review the results as per 5 (Part 2, clause 8 is still there, and it's not going away) (note: API RP 581 might help a little with the risk assessment as that is where you will be heading)
10. If it is still a problem, think about what destructive tests could be performed whilst still offering a chance of keeping the vessel
11. Either give up, or make sure you are not on the plant
Steve Jones
Corrosion Management Consultant
All answers are personal opinions only and are in no way connected with any employer.