This video demonstrates what can happen to a vessel when the vacuum port is blocked or insufficient. Occurences of tanks failing under vacuum are far more frequent than those failing under overpressure.

 

A video demonstrating a crude oil boilover.

 

This footage show what happens to a vessel when it is subjected to rapid cooling without sufficient vacuum relief. This is exactly what can happen to an atmospheric storage tank which lacks adequate venting, for instance when rapidly cooled by a rain storm on an otherwise hot day.

 

A demonstration of a Boiling Liquid Expanding Vapour Explosion, also known as a BLEVE.

 

An explosion within a storage tank with a frangible roof design. The fire causes a huge build up of pressure which is relieved by the tank roof lifting. An alternative method of relief is through Emergency relief vents (ERV’s).

 

This footage is hugely valuable as a learning resource. A fire is sparked by a lightening strike. This travels from the first tank to the adjacent tank. You can see the tank in the foreground relieving vapour through its pressure relief vent from 0.06. This vapour ignites and visibly shows the pressure within the tank building and falling as it relieves. As the fire on the original tank rages, the tank in the foreground builds up some much pressure that it can no longer be sufficiently relieved by the pressure relief vent. In a correcty configured tank, the increase in relief required would be served by either a frangible roof or an emergeny relief vent. In the absence of these, the pressure builds until the entire tank leaves the ground at 0.44 (tank anchors?), producing an enormous fireball. Interestinly enough, the other tank in the foreground is then consumed by fire and is also subjec to an overpressure – this tank however is protected by a frangible roof which departs the tank at 1:34, sending a smaller fireball vertically upwards and away from the surrounding tanks.

 

A fuel tank explosion filmed from distance – note the shockwave formed.

 

Again, an explosion at a chemical plant, demonstating the frightening power that an incident of this nature can produce.