Application of computerised radiography in lieu of film radiography to streamline on-site pipe weld quality inspection process

Conventional film radiography has long been the dominant method of non-destructive testing in the Australian pipeline industry. Although proven, the process has disadvantages, including environmental issues with chemical processing and film disposal, significant archival space requirements, film deterioration, and difficulty in traceability and safe sharing with others. In contrast, computerised radiography (CR), using a phosphorus-laden reusable imaging plate and X-ray radiation to generate a latent digitally scannable image, is a clean, compact and efficient process. Although CR has been used on other applications, such as profile radiography for more than a decade, the process has not been considered advanced enough for weld testing until now. After a comprehensive qualification/validation process, CR was successfully used on 481 km of the 622-km-long Northern Gas Pipeline (NGP) Project by McConnell Dowell in the Northern Territory. Proven on approximately 26000 welds, this thinking has changed for good.