Typical Image Interpretation of Phased Array Ultrasonic Inspection of Welds in Pressure Equipment

Based on the latest ASME Code(revised and enlarged edition 2009) requirements of inspecting welded joints in pressure equipment by ultrasonic phased array technology, this article presented some cases of reading typical PA images in consist of PA S-scan displays of common welding defects and the sectional view of used inspection arrangement. The inspected objects were single-V groove welds and T-joint butt welds, for which there were some difficulties in inspection comparing with the common double-X groove welds. The defects included toe cracks, underbead cracks, inner-surface breaking cracks, side-wall lack of fusion, incomplete root penetration, and porosity and so on. A comparison between the sizing result by PA inspection and the actual defect size was also given.