The U.S. Chemical Safety Board this week released a 65-page report on the Feb. 16, 2007 fire at Valero’s McKee Refinery in Sunray, Texas, and outlined a number of causes and remedies so a similar incident can be avoided in the future.

Valero, on the other hand, said it implemented safety measures throughout its refining system on its own and in advance of the report from CSB.

The refinery fire erupted that day when a propane deasphalting unit sprung a leak. It was determined that ice had formed in a remaining pipe from a system that was no longer in use.

Valero said its own findings were consistent with CSB’s. “The ice caused a rupture in the pipe, which led to a propane leak that ignited and caused the fire at the refinery’s Propane Deasphalting Unit,” Valero said. “The CSB recommended removal of those unused pipelines – a process that Valero has already initiated as part of its internal safety measures.”

Three workers suffered serious burns from the incident, and the refinery was shut down for some time.

“Well before the CSB issued its report on the fire and recommendations for changes, Valero had begun its own investigation and developed new safety initiatives throughout its system,” Mike Mayo, Valero’s director of corporate safety, said in a press release. “These steps include the creation of a corporate Process Safety Management and Reliability Department to develop and oversee safety and related process reliability measures at all our refineries.”

Valero said it also replaced the refinery’s damaged Propane Deasphalting Unit with a new, redesigned unit that offers upgraded control systems – including remotely operable shut-off valves – designed to reduce the risks of such incidents.

Also as a result of lessons learned from the McKee fire, Valero said it is re-evaluating the fireproofing of structures such as pipe racks at its refineries, and by year-end will have completed switching from using chlorine to a safer bleach solution in order to treat cooling water.

Valero said it has an employee injury rate well below the industry average.

“Safety is our top priority and an ongoing effort for Valero,” Mayo said. “Our goal is to eliminate incidents like the fire at McKee altogether, which is why we continually take steps to guard against and mitigate the risks associated with our processes.”

CSB listed the fire’s root causes:

  • The McKee Refinery had no formal written program in place to identify, review, and freeze-protect dead-legs or infrequently used piping and equipment, such as the propane mix control station.
  • The McKee Refinery did not apply Valero’s mandatory Emergency Isolation Valve procedure when evaluating risks in the PDA unit to ensure that the large quantities of flammable materials in the unit could be rapidly isolated in an emergency.
  • API guidance and Valero’s corporate Fire Proofing Specifications standard do not specify sufficiently protective distances for fireproofing pipe rack support steel for processes handling high-pressure flammables, such as the LPG in the PDA unit.
  • Other contributing causes: (1) API-recommended practices on locating and operating LPG firewater deluge valves do not address potential hazards from nearby processes, and (2), Valero–McKee Refinery’s hazard assessment process did not recognize the risk of using chlorine in close proximity to equipment handling flammable hydrocarbons.

    The full report can be viewed at www.chemsafety.gov

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