Where should water be applied on a compressed gas tank that is in danger of rupturing?

Applying water to the upper portions of a compressed gas tank that is in danger of rupturing is crucial for several reasons. The primary goal is to cool the tank and reduce the pressure inside. Compressed gas tanks can become extremely pressurized due to the heat of a fire, and excessive heat increases the risk of rupture or explosion.

By directing water to the upper portions of the tank, you are effectively cooling the most critical areas that are potentially under the most stress from heat. This cooling helps prevent the tank from reaching its critical failure point. It is also important to note that cooling the upper sections can help manage the vapor space in the tank, which is where flammable gases may be present.

Other options could lead to ineffective cooling or create additional hazards. For instance, applying water to the lower portions of the tank may not reach the areas most affected by heat, while direct application onto a fire can be dangerous and may not be effective in mitigating the risk associated with a compressed gas tank. Therefore, focusing on the upper portions of the tank is an effective strategy in such emergency scenarios.