OPG’s plants currently use radiography testing (RT) as part of the FAC program for smaller diameter piping in order to mitigate removal of insulation and due to a preference for visual images of degradation. However, it would be preferable to use phased-array ultrasonic testing (PAUT) in lieu of radiography for manpower, exposure, and safety reasons. This paper presents newer types of PAUT probes which can be contoured to the surface of the component being inspected. The use of this type of probe was predicated by a need to inspect piping elbows of NPS 4” and less for which there are limited PAUT solutions available. Most scanners cannot traverse elbows, or are not configured for smaller pipe diameters. The goal with the application of a flexible array probe was to eliminate the need for multiple probe/wedge combinations and utilize a single design over a range of elbow diameters. The problem was approached in two ways: a traditional method involving small footprint PAUT probes with custom wedges for each pipe diameter, and an all encompassing solution aimed at using a single transducer to inspect the full range of pipe diameters. This paper focuses on the second approach. An exhaustive search for potential tooling was conducted through available manufacturers. Out of the available options (bracelet scanners, custom manual weld scanners, and wheel-probe scanners), the passive flexible array probe design was settled on for its relative simplicity requiring only a change in setup file to work with different sized elbows.

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