Describe the signs and effects of boiling liquid expanding vapor explosion (BLEVE).

Description should include the signs of an impending explosion, such as

• discoloration of the metal container
• the pinging sound associated with heated and expanding metal
• a bulge or bubble in the metal container
• increase in size and intensity of the relief-valve flame.

When a BLEVE explosion occurs, pressure from liquids turning into gas have forced the expansion of the metal container to its breaking point, causing a rupture and producing a fire ball that shoots fragments from the container in all directions.

Process/Skill Questions:

• What is the purpose of a relief-valve flame, and why does it increase in size when experiencing BLEVE?
• What is the best method for preventing BLEVE?
• What causes the pinging sound associated with BLEVE?
• What are the effects of heat on pressurized flammable gases?
• How does a firefighter decide when to retreat when dealing with pressurized flammable gases?