Mechanical & Materials Engineering

Thermal Hazards Laboratory

BLEVE Research

The boiling liquid expanding vapour explosion (BLEVE) happens when a vessel holding a pressure liquefied gas (PLG) fails catastrophically. The vessel failure may be due to:

  • severe fire exposure
  • severe overpressure Propane BLEVE
  • severe corrosion
  • severe mechanical impact
  • severe manufacturing flaw
  • or a combination of all of the above.

A pressure liquefied gas (PLG) is normally a vapour at ambient pressure and temperature but is stored as a liquid under pressure at ambient temperature. If the containment is suddenly lost then the liquid is sent into a state of superheat, and this can lead to sudden and violent phase change of a large fraction of the liquid. The BLEVE is the explosive release of expanding vapour and flashing liquid. Hazards from a BLEVE include blast overpressure, projectiles, possible toxic release and if flammable a fireball, flash fire or vapour cloud explosion (VCE).

Dr. Birk has been conducting research in the following areas:

  • Fire Effects on Pressure Vessels holding Pressure Liquefied Gases
  • Thermal Protection of Pressure Vessels
  • Computer Modelling of Vessels in Fires
  • Boiling Liquid Expanding Vapour Explosions (BLEVE)
  • Modelling Hazards from BLEVEs (fireball, blast and projectiles)
  • Pressure Relief Valve Testing and modelling
  • Fire Testing of Pressure Vessels
  • Benefit Analysis for Thermal Protection Systems
  • Thermographic Inspection of Thermal Protection Systems

This work has been funded by Transport Canada, Transportation Development Centre, Transport of Dangerous Goods Directorate, NSERC, RCMP Canada Bomb Data Centre, and companies in the propane industry.

Research Activities

Michael Birk

Since the early 1990's Dr. Birk and his team have conducted numerous large scale tests of propane storage and transport tanks subjected to various types of fire impingement. These were specifically designed fire tests to study certain weaknesses in the vessel design or thermal protection system. Some tests were specifically designed to study the boiling liquid expanding vapour explosion or BLEVE as it is commonly known. In all cases the tanks and surroundings were heavily instrumented to measure tank and lading temperature distributions, tank internal pressure, high speed transient pressures during failure, and far field thermal radiation and blast overpressure.

From 1992 to 1996 Dr. Birk directed a major fire test program where over forty 100 gallon ASME code automotive propane fuel tanks were exposed to jetting fires and engulfing pool fires. This work was conducted to study the boiling liquid expanding vapour explosion (BLEVE).(click here to learn more about the BLEVE Tests)

From 2000 to 2004 Dr. Birk conducted a major large scale test program involving twenty 500 gallon ASME code propane storage tanks to study various aspects of vessel design including thermal protection systems. They looked at the effects of pressure relief valve blowdown on tank failure modes. They also measured the effects of wall thickness reductions on tank survivability. Tests were also conducted to study specific thermal protection defects. All of this work provided detailed data to help develop and validate computer models for tanks in fires.(click here to learn more about PRV Field Trials)

Michael BirkOther examples of research conducted by Dr. Birk and his team include:

  • development of thermal models for predicting fire effects on tanks in and near fires (click here to learn more about Tank Thermal Modelling)
  • conducted an analysis of a propane tank located near a burning building for the Province of Quebec and the Government of Canada. The objective of the study was to determine if current codes for locating propane tanks near buildings are safe. This work was funded as a result of a propane tank BLEVE that claimed the lives of some firefighters in Quebec.
  • major PRV (pressure relief valve) test program for Transport Canada. This work resulted in the collection of data showing how PRVs operate under real fire conditions. The results showed that some PRV's have highly variable performance and many do not meet the codes for which they are stamped.
  • developed a thermographic inspection technique for locating thermal insulation deficiencies in rail tank-cars carrying dangerous commodities. This technique has proven to be highly effective in the field and it has already generated some data indicating that deficiencies can be significant (click here to learn more about insulation defects study) . Dr. Birk recently completed a follow-on contract to develop insulation deficiency assessment criteria for field inspectors. This work involved computer modelling of common deficiencies to see how they affect the overall tank response to accidental fire impingement.
  • conducted numerous fire tests of tanks and cylinders including steel, aluminum and fibre wound composite cylinders.

In 2006 and early 2007 Dr. Birk and his team carried out a detailed design for the full scale engulfing fire testing of thermally protected Rail Tank-Cars for the Transport Canada. This testing will involve up to four 33,000 gallon (125,000 litre) tank-cars and is planned for 2008-2009. The work will be a collaborative effort between Canada and the US. The last time tank cars were fire tested in North America was in the early 1970's. These new tests are intended to give much more detailed data on the improved systems used today. Once again, this data will be used to ensure our computer models are accurate and fully validated.

Graduate Students

Dr. Birk has a number of graduate students working with him. The following is a list of projects that are available for interested graduate students.

  • computer modelling of pressure vessels in or near fires
  • computer models of BLEVE hazards (fireballs, blast, projectiles)
  • close in blast effects from BLEVEs
  • effects of BLEVEs in buildings and tunnels
  • modelling of 2-phase releases from punctured and ruptured pressure vessels

If you are a highly qualified and motivated person and are interested in one of the above, or a related project, then send a letter of interest along with a CV to A. M. Birk (birk@ME.QueensU.CA).

Sample Results from Queen's BLEVE Research

The following are examples of figures that are available in Dr. Birk's research publications. If you want more information on this work, you should obtain the full publications as listed for A. M. Birk.

Video Samples

Here are some examples of propane BLEVEs. These vessels were purposely exposed to very severe fires to cause them to suffer total loss of containment and BLEVE.

Other Samples

Here are some samples of pictures and plots from Dr. Birk's research on BLEVEs.

BLEVE pictures


If you are interested in the Transport Canada BLEVE Video (released fall 1995) contact A. M. Birk at:

(birk@ME.QueensU.CA). The video may be previewed and purchased by following the links below.


Revised by A. M. Birk May 2011