Information AboutBleve |
| CATEGORIES ABOUT BLEVE | |
| explosives | |
| firefighting | |
| fire | |
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A BLEVE can occur in a vessel that stores a substance that is usually a Gas at Atmospheric Pressure but is a Liquid when pressurized (for example, Liquefied Petroleum Gas ). The substance will be stored partly in liquid form, with a gaseous vapor above the liquid filling the remainder of the container. If the vessel is ruptured — for example, due to Corrosion , or failure under pressure — the vapor portion may rapidly leak, dropping the pressure inside the container and releasing a wave of Overpressure from the point of rupture. This sudden drop in pressure inside the container causes violent Boiling of the liquid, which rapidly liberates large amounts of vapor in the process. The pressure of this vapor can be extremely high, causing a second, much more significant wave of overpressure (i.e., an explosion) which may completely destroy the storage vessel and project fragments over the surrounding area. BLEVEs can also be caused by an external fire nearby the storage vessel causing heating of the contents and pressure build-up. A BLEVE does not require a Flammable substance to occur, and therefore is not usually considered a type of Chemical Explosion . However, if the substance involved ''is'' flammable, it is likely that the resulting cloud of the substance will ignite after the BLEVE has occurred, forming a fireball and possibly a Fuel-air Explosion , also termed a vapor cloud explosion (VCE). If the materials are toxic, a large area will be contaminated.http://maecourses.ucsd.edu/ceng124/pdfs/safety-notes.pdf accessed 2006-11-04 Significant industrial BLEVEs include accidents at Feyzin in France in 1966 , Kingman, Arizona in 1973 , Texas City, Texas in 1978 , and San Juan Ixhuatepec in Mexico in 1984 . In 1978 , a BLEVE occurred after a road accident with an LPG truck in the Los Alfaques Disaster in Spain . If a gas cylinder is venting, a BLEVE can be avoided by cooling the cylinder involved with water or foam, taking care not to extinguish the flame, until the cylinder is empty, or the leak is plugged. Other fire mitigation measures are listed under Liquefied Petroleum Gas . NOTES http://www.protecht.org/en/index.php?link=glossary http://maecourses.ucsd.edu/ceng124/safety/safety-notes.pdf The term was first used was in Kansas City MO, on August 18 1959 . Cited -- KCFD History http://www.kcfiremuseum.com/history_of_the_kansas_city.htm SEE ALSO EXTERNAL LINK
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