Long Term (1970 to 2015) Trending of the Nine Prescriptive Pipeline Threats

Since the 1970s, the United States Department of Transportation (USDOT) Pipeline and Hazardous Materials Safety Administration (PHMSA) has collected and published pipeline failure incident data. Operators are required to report pipeline incidents and provide the apparent cause of failures. PHMSA and ASME (B31.8S for gas and B31.4 for liquids) identify and group these failures into nine broad categories and sub-classify them into three clusters by their time-based behavior. Technical advancements in pipe manufacturing, fabrication, construction, operation, inspection, monitoring, maintenance, rehabilitation and regulation have resulted in a decrease in incidents for many of these failure causes. This paper presents a statistical trending analysis of the failure incidents for each of the nine threats. The multi-year trending of these incident metrics over the last 40+ years will be demonstrated.