Hard spots are areas on the pipe surface with a hardness level higher than that of the surrounding metal. They are associated with a change in microstructure resulting from application of a localized and uncontrolled thermal cycle. In the majority of cases, pipeline hard spots are created during the manufacturing or construction process. Those areas on the pipe surface with a higher hardness present a latent threat. They can be more susceptible to cracking mechanisms and this threat is increased when they exist in combination with other threats. Due to several pipeline incidents related to hard spots in North America in recent years, regulatory authorities have begun to look into this issue with increasing attention, making hard spot detection essential for pipeline operators.
MANAGING THE THREAT OF HARD SPOTS
Managing the threat of hard spots is challenging. The starting point of any coherent, holistic integrity management strategy is data collection. Hard spots can occur at any point across the circumference or the length of a pipeline. ROSEN’s dual magnetization system (DMG) can reliably detect, identify and size hard spots. A market-unique combination of high-resolution in-line inspection (ILI) technologies, including Eddy Current, delivers unparalleled data that forms the basis for a well-rounded integrity engineering approach. This approach, which considers susceptibility, verification, and response strategies, provides the optimal solution for managing the threat of pipeline hard spots.