The case for 100% ultrasonic testing of steel sleeves
Pipeline operators often rely on the use of steel sleeves to repair a defect feature found on a pipeline. Once installed, the repair sleeve is commonly seen as an ‘extension’ of the pipe itself. However, while the carrier pipe has, in most cases, undergone the most stringent inspection required by industry specifications (often including NDE), steel sleeves require no such mandated testing – or, indeed, any validation testing at all. Steel sleeves are typically manufactured via formed plate material.
Manufactured plate undergoes a largely modern and routine manufacturing process; however, these processes are not immune to mid-wall or slightly subsurface features forming in the plate – which will eventually become the sleeve. While many surface features can be identified visually, subsurface features require some sort of through-thickness non-destructive examination (NDE) process. Limited NDE is performed while manufacturing the coil or plate, so anything later fabricated from this material relies solely on the manufacturing process, of which there exists no standardised requirements.
Allan Edwards has identified the lack of a uniform inspection requirement as an industry gap and has addressed this gap through the introduction of fully automated PAUT capabilities to its manufacturing process. This paper explores the benefits of PAUT technology, how it ensures a highly validated and transparent repair, and the implications this technology carries for the wider pipeline industry. With the incorporation of PAUT into its manufacturing standard for steel sleeves, Allan Edwards is ensuring that the quality of the repair product matches the inspection standard of the carrier pipe that it is reinforcing.