Systemic manufacturing defects in select vintage pipe pose challenges when assessing the integrity of pipeline systems comprised of such pipe. The common manufacturing technology and quality control practices in place at the time of manufacturing left some vintage line pipe prone to imperfections which could remain even after passing pressure tests in the mill or after construction. The lack of complete and reliable manufacturing records for some vintage line pipe limits granularity and adds integrity assessment uncertainties.
Up until 1984, the United States Department of Transportation (USDOT) Pipeline and Hazardous Materials Safety Administration (PHMSA) required operators to report incidents related to failed pressure tests for all pipelines at the time of installation. Performance with respect to the manufacturer and year of manufacture can therefore be extracted from these reported incidents. These performance records are essential when re-establishing the MAOP (or MOP) and confirming the fitness for service of older pipelines. The pressure test failure performance in the early incident records provides insight into pipeline integrity prioritization and mitigation activities for managing pipeline safety based on pipe manufacturer, production date and seam type.
