The hazard of pressure tanks involved in fires

Tanks devoted to the storage and transportation of liquefied petroleum gases (LPGs) are exposed to serious hazards when involved in a fire. Under particular conditions, the boiling liquid expanding vapor explosion (BLEVE) can occur with catastrophic consequences. In the present paper, a mathematical model developed to evaluate the LPG tank behavior for different fire scenarios is presented. Major hazards have been identified distinguishing, in order of gravity, among jet release, catastrophic loss of containment, i.e., the failure of the tank followed by rapid evaporation of the superheated liquid without the development of blast waves, and BLEVE. The effects of accidental cracks, of the presence of a pressure safety valve, and of an insulating layer have been investigated as well. Eventually, the severity of the fireball, of the blast wave, or of the fragments produced by the BLEVE has been assessed as a function of both the scenario and the thermal condition of the containment at the moment of failure.