BLEVE
Definition
Boiling liquid expanding vapour explosion. Catastrophic failure of a vessel containing a superheated liquid, producing an expanding pressure wave and, if the liquid is flammable, a fireball.
- Full form
- Boiling liquid expanding vapour explosion
- Trigger
- Vessel wall failure under a superheated pressurised liquid
- Hazard if flammable
- Fireball follows the initial pressure wave
- Common source vessels
- LPG tanks, propane cylinders, boilers exposed to external fire
Common questions
What physically happens in the moment of a BLEVE?+
A liquid held above its normal boiling point by container pressure suddenly loses containment, usually from fire weakening the vessel wall. The liquid flashes to vapour almost instantly, and that near-instantaneous phase change drives the expanding pressure wave, independent of whether the substance is flammable.
How is a BLEVE distinguished from a chemical explosion at the scene?+
Investigators look at the vessel itself: BLEVE fragments typically show ductile tearing and thinning from fire-induced weakening rather than the brittle, high-velocity fracture patterns of a detonation. The presence of external fire damage before failure and vessel geometry consistent with pressure-relief failure both point to BLEVE rather than an intentional device.
Related terms
- API 579
- The American Petroleum Institute's Fitness-For-Service standard, which provides assessment methods for determining whether a damaged or corroded pressure vessel or piping component...
- Corrosion Under Insulation (CUI)
- External corrosion of a pipe or vessel surface that occurs beneath thermal insulation, hidden from visual inspection, driven by moisture infiltrating the...
- Deflagration
- A subsonic combustion front propagating through an explosive by thermal conduction. Characteristic of low explosives such as black powder and smokeless powder;...
- Detonation
- A supersonic shock wave coupled to a chemical reaction front, propagating through a high explosive at velocities between approximately 4,500 and 9,100...
- Overpressure
- Pressure above ambient atmospheric pressure produced by an explosion. The peak overpressure and its duration (impulse) together determine structural damage and injury...