What is the best way to prevent a BLEVE of a horizontal propane tank?

• A. approach from the side of the tank and cool it with water streams
• B. approach from the end of the tank and apply dry chemical powder
• C. spray foam onto the top from a distance
• D. evacuate area and wait for the tank to vent naturally

Answer: (A)

Preventing a BLEVE hinges on removing heat from the propane tank fast enough to keep the metal shell and its fittings from overheating. Water is the most effective cooling agent here because it absorbs a lot of heat as it turns to steam, which slows the rate at which the liquid propane inside boils and the pressure inside rises. Directing large streams of water onto the side of the horizontal tank cools the shell evenly and protects the main body where heat transfer is most critical, helping to prevent the relief devices from being stressed and a catastrophic failure.

Approaching from the side is preferred because it allows you to blanket the tank’s surface with cooling water and maintain a safer stance relative to the valve end and potential ignition sources. Other tactics, like spraying foam on top or applying dry chemical, don’t provide the same rapid, surface-wide cooling needed to avert rupture. Evacuating and waiting for the tank to vent naturally gives heat time to build and can lead to a BLEVE before venting occurs.