Created on March 14, 2016

When discussing about BLEVE in the middle of meeting session, I tried to share the “Lesson Learned” related how it happened and how to minimize its escalation if BLEVE scenario occurred within production facilities.

BLEVE itself stands for “Boiling Liquid Expanding Vapor Explosion”. A BLEVE can occur when a pressure vessel containing a flammable liquid (like propane tank, LPG tank, etc) is exposed to fire so that the metal loses strength and rupture (blast).

If we look up the book of “Lee’s Loss Prevention in the Process Industries”, it provides us the following description of a BLEVE:

When a vessel containing a liquid under pressure is exposed to fire, the liquid heats up and the vapor pressure rises, increasing the pressure in the vessel. When this pressure reaches the set pressure of the pressure relief valve, the valve operates. The liquid level in the vessel falls as the vapor is released to the atmosphere. The liquid is effective in cooling that part of the vessel wall which is in contact with it, but the vapor is not. The proportion of the vessel wall which has the benefit of liquid cooling falls as the liquid vaporizes. After a time, metal which is not cooled by liquid becomes exposed to the fire; the metal becomes hot and then may rupture.

Based on description above, I tried to summarize with a few essential features of a BLEVE scenario. In the simple way, they are:

  • The vessel fails,
  • The failure results in a flash-off of vapor from superheated flammable liquid, and
  • Vapor ignites and results in explosion.


This BLEVE incident has occurred in so many industries around the world, killed many people, and has damaged surrounding area/ environment by its explosion. People competency or miss understanding in responding BLEVE scenario causes escalation of the consequences. For example: people believed that they would be protected from an explosion of they avoided the ends of the tank; people assume that the relief valve (for venting) will prevent over-pressurization, rupture, and explosion of the tank being exposed to fire while containing flammable liquid; etc.

CSB incident investigation report (http://www.csb.gov/) also provides us the following mechanism to respond BLEVE properly:

  • Do not assume that the relief valves will prevent over-pressurization and rupture,
  • Apply large quantities of water to the tank,
  • If a flame is impinging on the tank, water must be applied directly to the impinged area in order to prevent BLEVE,
  • Water should be sprayed by using of an unmanned fire hose system,
  • If a continuous supply of water is not available, withdraw & isolate the area for 1 km in all direction.


So, in BLEVE scenario context, which condition will be more dangerous if the tank is being exposed to fire:

  • A pressurized vessel with half-full flammable liquid inside? or
  • A pressurized vessel with almost full flammable liquid inside?


Kind Regards,

Beny Destiawan
Process Safety Engineer
LebSolution Indonesia


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