Philippe Rioux, Jonathan Turcotte, Philippe Cyr
Phased Array inspection of curved parts brings some real technical challenges. Evaluation of seam welds on small diameter and heavy wall pipes is difficult to accomplish using actual tools that, most of the time, are based on a flat surface model. This often leads to erroneous and imprecise flaw location and sizes. Furthermore, interpretation of the S-Scans becomes very difficult in these circumstances. Trying to take into consideration the effect of the convex surface reflection is something the current instrument imagery is not taking into account and is very difficult for the operators to correct themselves. The typical tools like presenting an overlay of the weld just can’t be used in a practical way.
This paper presents a totally new approach of inspecting seam welds and more generally curved parts. The novel method rethinks almost all aspects of the traditional implementation. Starting from an original focalisation of beams that allows the technician to define specific focal points in a zone of interest. As well, we describe how the live data is represented in a 3D scan plan in order to facilitate interpretation and identification of flaws. Corrected A-Scan views are also produced, allowing to perform accurate measurements. We finally touch on how to calibrate the instrument prior to performing these inspections on curved surfaces.