An opening commonly associated with a BLEVE is called

• A. Runaway cracking
• B. Relief vent
• C. Vent opening
• D. Crack propagation

Answer: (A)

When a vessel containing a volatile liquid is heated, pressure inside rises as the liquid turns to vapor. If the wall can’t contain that pressure, cracks form and then spread rapidly through the material. The opening that results from this fast, uncontrolled growth of cracks is what’s being described—runaway cracking. This rapid crack propagation creates a large breach through which superheated vapors and liquid escape, often leading to the explosive release typical of a BLEVE. The idea here is that the opening isn’t a planned vent, but a sudden, accelerating fracture of the vessel wall.