Simulation for the Phased Array Ultrasonic Inspection of Small Bore Piping Socket Welds

Small bore pipes with nominal diameters less than 2 inches are typically utilized for temperature sensing, pressure sensing, draining, or sampling in the pressure boundary of a nuclear power plant. Socket welds connected with these pipes are generally inspected by surface examination according to the code for performing in-service inspections. Moreover, volumetric-based phased array ultrasonic inspection methods have also been applied to enforce inspection requirements in Korea. The phased array ultrasonic signals received from the socket welds are more complicated than those of conventional ultrasonic testing for detecting cracks in piping welds owing to the complex geometry of socket welds. Therefore, the identification and characterization of indications are essential for reliable inspections, and ultrasonic simulation tools can be used to understand the complex phenomena of ultrasonic waves in socket welds. In this study, the phased array ultrasonic inspection of flaw specimens with small bore socket welds was simulated using an ultrasonic simulation tool and the results were compared with the experimental results.