Other burns, unspecified

A crew was changing out a vertically oriented 8-inch check valve on a pipeline. When a flange was opened by loosening bolts, pentane and other flammable hydrocarbon products in the pipe released from the pipeline, creating a vapor cloud and resulting in a massive fire and explosion. The vessel and associated equipment/piping were engulfed in fire for about eight hours. Eight employees were sent to the hospital. Six employees were treated and released. Two employees were admitted for treatment of thermal and chemical burns to the face, neck, and hands.