Bureau Veritas has developed and approved a semi-automated phased array ultrasonic testing (PAUT) solution, enabling the replacement of radiographic testing (RT) for thin-wall austenitic stainless steel piping welds on LNG-fueled vessels.
Traditionally inspected using radiography, these welds present specific technical challenges due to material characteristics and reduced wall thickness. Radiographic testing also involves radiation sources, requiring safety exclusion zones and strict operational controls in shipyard environments.
To address these constraints while maintaining full compliance with classification requirements, Bureau Veritas France Industry developed a dedicated semi-automated PAUT procedure tailored to this application. The qualification program was conducted by Bureau Veritas Marine & Offshore in accordance with Bureau Veritas Rules NR216 and aligned with internationally recognized ultrasonic testing standards, including ISO 20601 and ISO 22825, as well as ASME Section V principles for qualification block design.
A comprehensive validation campaign was carried out using representative welded specimens incorporating both artificial reflectors and realistic manufacturing defects. The study demonstrated detection capability, validated full weld volume coverage and confirmed compliance with sensitivity requirements defined under the class framework. Comparative assessments showed that the semi-automated PAUT method delivers detection performance equivalent to, and in certain configurations superior to, conventional radiographic testing for this specific application.
Following technical review, the inspection procedure has been formally approved within the Bureau Veritas Marine & Offshore classification framework. In addition, the Brest operational unit of Bureau Veritas France Industry has been accredited as a non-destructive testing supplier under NR669, ensuring controlled and compliant deployment of the method.
Beyond its technical performance, the approved ultrasonic solution provides significant safety and operational advantages. As it does not rely on radiation sources, it eliminates the need for safety perimeters and allows concurrent shipyard activities. The semi-automated system enables rapid data acquisition, digital mapping and full traceability of inspection records, supporting efficient production scheduling and long-term structural integrity monitoring.
Christophe Chauviere, M&O Technical & Operations Excellence Senior Vice-President, Bureau Veritas, said:
“This approval demonstrates how classification can actively support industrial innovation while maintaining the highest standards of safety and technical rigor. By validating this advanced ultrasonic solution, we are combining the strengths of our Marine & Offshore and Industry experts to enable safer and more efficient ship construction processes without compromising quality. Through this initiative, Bureau Veritas reaffirms its commitment to supporting the maritime industry with innovative, standards-driven solutions that enhance safety, performance and sustainability in LNG-fueled vessel construction.”
