The report, prepared by Anamet, Inc., a metallurgical laboratory in Hayward, California, concludes that the 8-inch steel pipe, from a section designated as 4-sidecut which was installed in 1976, ruptured due to severe sulfidation corrosion, and that tested pipe samples showed a very low concentration of corrosion-inhibiting silicon.
CSB Chairperson Rafael Moure-Eraso said, “The report, resulting from a cooperative effort between the CSB, Cal/OSHA, the United Steelworkers (USW), and Chevron provides a solid, technical basis for the firm conclusion that the pipe corroded over time from sulfidation corrosion. We hope this report receives widespread attention throughout the petrochemical industry as a precaution to all refiners to carefully examine potential corrosion mechanisms and use the safest possible materials of construction to avoid failures. Refineries and other plants must incorporate strong mechanical integrity and inherently safer strategies in their process safety management programs.”
Cal/OSHA Chief Ellen Widess added “This reports confirms what Chevron already knew– that the pipe was severely corroded and should have been replaced – but failed to act on before the August fire. This failure to act was included among the multiple Serious and Willful Serious citations issued to Chevron. Chevron’s own metallurgists and pipe inspectors reached the same conclusion and recommended as far back as 2002 that Chevron take action to protect its workers, the community and the environment by replacing the pipe that finally ruptured in 2012.”