Evaluation of a pressure vessel using failure analysis diagram based on phased array ultrasonic testing data

ABSTRACT A pressurized gas separator vessel was scanned to detect the possible discontinuities using a Phased Array Ultrasonic Testing (PAUT) device. Ultrasonic results from Hydrogen-Induced Cracks (HICs) at different depths were considered to represent the evaluation procedure. Final results were then generated for implementing Fitness-for-Service (FFS) procedure. After considering FFS procedures, it was found that some of the discontinuities are not acceptable due to their sizes or locations. Based on the simulated model results, including fracture analysis of cracks and generating Failure Analysis Diagrams (FAD), it can be inferred that the vessel is not acceptable to be in the current service operation condition and should be replaced.