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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Pipeline Safety: Identification and Evaluation of Potential Hard Spots-In-Line Inspection Tools and Analysis

Notice; issuance of advisory bulletin.

PHMSA is issuing this advisory bulletin to notify pipeline owners and operators of the importance of evaluating their pipeline facilities for the existence and potential threat of hard spots in the pipe body. That susceptibility comes from the plate and pipe manufacturing and is broader than previously understood; recent data and incident investigations indicate that hard spots could affect multiple pipelines manufactured prior to 1970. Hard spots, if not identified and mitigated, pose a threat to the integrity of the pipeline from interacting threats such as coating degradation, soil chemistry, and/or increased hydrogen exposure, which can result in hydrogen-induced cracking. Pipeline owners and operators should consider expanding their hard spot threat evaluation to all pipe manufactured prior to 1970, regardless of manufacturer; collecting and analyzing data associated with hard spot magnetic flux leakage in-line inspection tools; and following industry best practices when conducting in-line inspection data analysis.

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