Influence of seamless pipes wall thickness variation for the effectiveness of Automated Ultrasonic Testing

Offshore pipelines construction is a technological challenge. Increasing water depth, harsh environments, engineering and commercial constraints are just some of the existing issues. Material selection therefore plays a key role and, for several applications, seamless pipes offer both the best technical and commercial compromise. Typically, NDT inspection of girth welds is carried out using the phased array based automated ultrasonic testing (AUT) zonal discrimination approach. AUT, compared to other techniques, guarantees a higher probability of detection of flaws and it also allows a really accurate assessment of the indications. However, since one of the peculiarities of this technique i…