API RP 579-1 / ASME FFS-1

This standard provides guidance for conducting fitness-for-service assessments using methodologies specifically prepared for pressurized equipment. Fitness-for-service assessments are quantitative engineering evaluations that are performed to demonstrate the structural integrity of in-service components that may contain a flaw or damage, or that may be operating under a specific condition that might cause a failure.

The guidelines provided in this standard can be used to make run-repair-replace decisions to help determine if components in pressurized equipment containing flaws that have been identified by inspection can continue to operate safely for some period of time. These fitness-for-service assessments are currently recognized and referenced by API codes and standards (510, 570, and 653), and by NB-23 (National Board Inspection Code) as suitable means for
evaluating the structural integrity of pressure vessels, piping systems, and storage tanks where inspection has revealed some level of degradation and/or flaws in the equipment.

This standard was developed by a joint API-ASME committee, is an ANSI American National Standard, and is recognized as an International Code.