Explosion due to hydrocarbon being drawn into boiler firebox

A leak in a hydrocarbon refrigerant system formed a vapor cloud that was drawn into the inlet of a steam boiler. The increased fuel to the boiler caused rapidly rising pressure within a steam drum. The rapidly rising pressure exceeded the capacity of the boiler’s safety valve and the steam drum ruptured. The boiler rupture was close enough to the gas leak to ignite the vapor cloud and produce an explosion due the confined nature of the gas lea  and an ensuing fireball. The fire took eight hours to extinguish. The explosions and fire destroyed a portion to the LNG plant and caused 27 deaths, and injury to 72 more.