Use of fitness-for-service methodologies in failure analysis

Fitness-for-service (FFS) evaluation methodologies are commonly used in the oil and gas industries to determine when a pipeline or other critical structure with measured damage—such as cracking, corrosion, or thinning—no longer meets design performance criteria. This presentation reviews additional applications of FFS evaluation methodologies, such as those found in API-579/ASME FFS-1 and BS 7910, to failure analysis. FFS evaluations were used to evaluate crack-like flaws in liquid natural gas (LNG) storage and piping components subjected to LNG release scenarios to gauge the failure likelihood of these components due to rapid temperature drop. FFS was also used in this application to provide insight on the type of non-destructive testing (NDT) methods that should be specified for the different components to avert crack-induced failures. FFS evaluations were also used to evaluate the plausibility of postulated failure scenarios of buried pipe subjected to wheel loading and welded pipe that failed during fabrication.