What expansion ratios do air aspirating nozzles produce?

Air aspirating nozzles are designed to mix air with water or foam to create an effective firefighting solution. The correct answer indicates that these nozzles typically produce expansion ratios of 3:1 and 5:1.

An expansion ratio refers to the volume of air that is mixed with a specific volume of liquid, resulting in a greater volume of foam or solution that can effectively cover a surface and combat fire. The ratio of 3:1 means that for every unit of liquid, three units of air are mixed in, while a 5:1 ratio means that for every unit of liquid, five units of air are mixed. This increased foam volume enhances the extinguishing effectiveness by providing better coverage and insulation for hot surfaces.

Understanding these ratios is essential in fire suppression tactics, as they influence the performance and efficiency of the foam generated. The ratios specified in the correct choice align with the common operational parameters established in fire protection standards and practices.