By BEN LEFEBVRE
Chevron said Tuesday a corroded pipe segment that is the focus of an investigation into the August fire at the company's refinery in Richmond, Calif., had not been included in a prior inspection and may have been unusually susceptible to corrosion.
Chevron and government officials are still investigating the cause of the fire at the 245,000 bpd refinery that sent black smoke billowing over the San Francisco Bay and area residents to hospital emergency rooms.
The Chemical Safety and Hazard Investigation Board had said earlier that the walls of a pipe leading from the refinery's crude distillation unit had corroded by 80%, making it at some segments as thin as a penny and likely to leak flammable material.
Chevron said Tuesday the pipe had an unusually-low silicon content, making it vulnerable to corrosion in high temperatures because of a process called sulfadation.
The company didn't check a 5-foot segment of the pipe during a routine inspection in November despite having removed a nearby pipe that showed signs of corrosion.
Unfortunately, we did not inspect the individual component that failed, said Nigel Hearne, general manager of the refinery. We are now inspecting every individual component in carbon steel systems exposed to sulfadation corrosion conditions.
Chevron said Monday that the UW Environmental Protection Agency was conducting a separate, criminal investigation into whether the Richmond refinery was illegally routing gas away from emissions monitoring equipment before flaring it into the air.
The Richmond refinery is the largest in the San Francisco Bay Area and accounts for nearly 10% of the refining capacity in the US West Coast. It produces gasoline, diesel fuel and assorted petrochemicals. The production outage following the August fire caused California gasoline prices to rise 30 cents.
Dow Jones Newswires
Cover photo courtesy of Alex Tafla via Flickr