Wildland Firefighting Practice Exam

For a propane tank fire, where should water be applied to the tank?

1. All around the base

2. Sides only

3. Vapor (upper) sides

4. Relief valve port

The correct answer is: Vapor (upper) sides

When dealing with a propane tank fire, applying water to the vapor (upper) sides of the tank is crucial for several reasons. Propane is stored as a liquid under pressure, and its vapor space, or the area above the liquid propane, contains flammable gases. By cooling the vapor space, firefighters can help to reduce the pressure inside the tank and minimize the risk of a catastrophic failure or explosion. Cooling the vapor sides also helps to prevent the pressure relief valve from activating prematurely, which could lead to a more dangerous situation if the escaping gas ignites. Targeting this area specifically ensures that the firefighters are addressing the most critical part of the tank in the context of fire control, mitigating the risk from both the fire itself and the potential hazards of the propane. Applying water all around the base or just on the sides of the tank might not effectively address the pressure and vapor concerns related to the fire, while focusing on the relief valve port alone would not adequately cool the areas that are most vulnerable to pressure buildup and fire risk. Thus, focusing on the vapor sides is the most strategic approach during a propane tank fire.