AUTOMATED ULTRASONIC INSPECTION OF PRESSURE VESSEL WELDS

摘要

ASME Code Case 2235 now permits automated ultrasonic testing (AUT) instead of radiography for vessels 0.5" (12.7 mm) or greater. Ultrasonic testing has significant advantages over radiography: no safety hazard so no disruption of production; inspection as soon as component cools; rapid feedback; defect vertical sizing for Fitness-For-Purpose applications; tailored inspections. ASME CC 2235 permits a variety of inspection techniques based on pulse-echo and Time-Of-Flight Diffraction (TOFD), provided a Performance Demonstration is achieved. This paper describes a number of AUT systems which fulfill the ASME code case. These AUT systems range from a portable phased array system (Omniscan) for low cost and convenience, through conventional systems based on TOFD (μ-Tomoscan), general phased array systems (Tomoscan III) to premium systems with multiple NDE approaches. With such a variety of technologies and costs, AUT systems can be tailored to the client's needs.