If the pressure relief valve changes in intensity on a liquefied gas tank fire, what action is recommended?

• A. Advance two 1-3/4 inch handlines with wide fog nozzles cooling both ends of the tank.
• B. Use one handline from an aerial position cooling the top of the tank.
• C. Withdraw from the area immediately.
• D. Use two handlines with wide fog while advancing to shut the pressure valve.

Answer: (C)

When a pressure relief valve’s discharge changes in intensity on a liquefied gas tank fire, it signals rising internal pressure and increasing danger of a BLEVE. The safest move is to withdraw from the area immediately and establish a defensive stance, keeping people away and isolating the scene. Trying to cool the tank from closer with lines, or attempting to shut the valve while the fire is active, can provoke a violent tank failure and release of gas. So stepping back to a safe distance and awaiting further plans or cooling from a safe location is the recommended approach.