Report examines cause of Chevron hydrocarbon release

Washington – The ruptured steel pipe at the center of the 2012 hydrocarbon release and fire at the Chevron U.S.A. Inc. refinery in Richmond, CA, was corroded and should have been replaced, concludes a report (.pdf file) released by the Chemical Safety Board and the California Division of Occupational Safety and Health.

The 8-inch pipe, which was installed in 1976, ruptured due to severe sulfidation corrosion, according to the report. Tests showed the pipe had a low concentration of silicon, which is used to prevent corrosion.

At the time of the rupture, employees were trying to determine the source of a “gas oil” leak in the pipe, which was connected to a crude oil distillation column. Gas oil is a combustible hydrocarbon liquid.

Six workers sustained minor injuries and thousands of nearby residents sought medical treatment after the incident.

Cal/OSHA has cited Chevron for multiple serious and willful violations, including failure to replace the corroded pipe even though Chevron’s metallurgists and inspector had recommended installing a new one since 2002.

The report was prepared by Anamet Inc., a metallurgical laboratory in Hayward, CA. CSB’s investigation to determine the root causes of the incident is ongoing, according to a press release.