Qualification of Phased Arrays to ASME Section V and Other Codes

Phased arrays offer major advantages over conventional radiographic inspection of welds: no radiation hazard, chemical disposal or licensing requirements; no disruption of production; near real-time inspection results, plus vertical defect sizing for Engineering Critical Assessment. In comparison with conventional ultrasonics, phased arrays are significantly faster, more flexible, reproducible, and can be tailored to the application. Overall, there is a strong interest in phased arrays, especially now that units are competitively priced and software is robust. However, the codes are not as advanced as the technology, as expected. In general, the codes accept phased arrays as a valid technology, but say little on the technique or procedures. This paper describes a typical process required to approve new inspection techniques for ASME Section V, specifically Olympus NDT’s OmniScan unit. The rationale and processes required for Section V, both Article 4 and the new Article 14 for novel techniques, is described. The various processes can be applied to: 1. Encoded electronic scanning (i.e. fixed angle raster scanning or E-scans), as in this case. 2. Encoded sectorial scans (S-scans) where the beam is swept through a range of angles, 3. and manual S-scans. A variety of techniques, procedures and reporting documents have been developed. There will also be updates on developments in other code areas: 1. ASME phased array code cases 2. ASTM recommended practice for phased array set-up. 3. AWS code developments, and 4. API approvals for portable phased arrays.