Bulletin Reminds of Liquid Pipelines' Corrosion Risks
A new advisory bulletin from DOT's Pipeline and Hazardous Materials Safety Administration reminds operators of hazardous liquid pipelines of the steps they must take to mitigate potential internal corrosion of the lines. The operators' responsibilities are spelled out by 49 CFR 195.579(a) and 49 CFR 195.589(c).
"Although the base commodity may not be corrosive, all hazardous liquids regulated under part 195 could be corrosive during some phase of the production and/or manufacturing process when contaminants could be introduced," the Nov. 24 notice states. "Often, the only barrier separating untreated product or corrosive materials from a pipeline transporting processed/refined products is the processing plant or refinery. These plants occasionally undergo upset conditions where all or a portion of the untreated product may bypass the treatment process and enter the downstream piping. During those upset conditions, corrosive materials might be introduced into the pipeline and could create a corrosive condition."
An operator's integrity management program must examine and record corrosion data; demonstrate an understanding of the risk of internal corrosion; identify the locations of greatest risk; conduct integrity assessments that will effectively discover pipeline defects caused by internal corrosion; promptly repair or remediate discovered defects; identify the root cause of discovered internal corrosion defects; and identify the need for additional or different preventive and mitigative measures, such as online pigging for removal of the corrosive materials and injection of corrosion inhibitors inline the product stream.
PHMSA said it will conduct a workshop on internal corrosion on hazardous liquid pipelines in the first quarter of 2009; information on the workshop will be posted at the agency's homepage.