A Novel Method for Nozzle-to-pipe Weld Inspection from the Nozzle Side

The ultrasonic non-destructive testing (UNDT) of nozzle welds is a major concern for the pipeline and vessel industry. The saddle geometry varies along with probe movement, complicating ultrasonic propagation and flaw characterization. This paper presents a novel nozzle-side inspection methodology to address these challenges, using a linear phased array and single-axis encoder-free rotational scanner. Through considering ultrasonic wave reflections at boundaries, the multi-view PWI achieves high-resolution imagind and enables characterization of both weld defects and the nozzle geometry. CIVA UT software was used to simulate inspection of cracks, cavities and flat bottom holes in a nozzle weld. Results show the nozzle sidewall appears as vertical cracks, with positioning accuracy within 0.21 mm. This enables deducing the probe’s circumferential position without encoders. All simulated defects were characterized with position and sizing deviations less than 0.34 mm, demonstrating the proposed method’s utility for enhanced nozzle weld inspection.