TORRANCE : Blast at Mobil Refinery Blamed on Gap in Pipe

A fiery explosion at a Torrance refinery last month apparently occurred when a gap in a pipe allowed flammable gases to escape into the air, Torrance fire investigators said Tuesday.

The gases were ignited, probably by a nearby heating unit, leading to the Oct. 19 explosion at the Mobil Oil Corp. refinery that injured 28 workers, according to the report from the Torrance Fire Department. Investigators did not blame any individual or procedure for the accident.

They focused on a 6-inch pipe running about 25 feet above the ground in a pipe rack near the refinery’s alkylation unit. That pipe had been disassembled at a flange fitting, with one open end sealed and one left unsealed, the report said.

On the day of the fire, a Mobil worker who apparently thought the pipe was intact began opening a valve in the pipe, the report said. When he saw a white vapor cloud forming below him, he started to close the valve but the explosion occurred. Gases in the pipe consisted of propane, butylene and butane, fire officials said.

In a statement Tuesday, Mobil said it would use the report in its own investigation, which it said would be finished soon. The accident also is being probed by the California Occupational Safety and Health Administration, the South Coast Air Quality Management District and by an independent consulting firm.