Dear Noel,
This type of situation is most of the time faced by welding and quality engineers. For this reason quality assurance activities are performed prior to product realization. In this process basically all the documents are properly reviewed and ensured for compliance for client requirements. we must review the documents - Technical/construction specification(API 650), client specification, client additional requirements and/or any other documents. based on these documents the quality Assurance/control plan is required to be prepared and subsequently approved from clients. once this QAP/QCP approved, further requirement shall be considered as additional requirement.
Being manufacturer,you may proceed in this way
1. if you realize this is impractical at this moment, you should request for non feasible activities at this moment.
2.perform the welding procedure qualification based for critical welding parement and show the results of hardness on test coupon.based on these results request for acceptance of production weld quality and subsequently revise the PQR/WPS if required.
3. If feasible, and time permits, cost calculation shall be performed and submit cost implication and subsequent time constraints.
Regards
Rishikesh kumar
Global Technical Support|Business Development|Lead Auditor|QA&QC|Welding| Pipe Mills|Steel Plants|Metallurgist