A foam inductor is a critical firefighting device used to proportionally mix foam concentrate with water to create a fire-suppressing foam solution.

Operating on the Venturi principle, the inductor is connected to a fire hose line. As pressurized water flows through its tapered internal chamber, it creates a vacuum. This vacuum draws foam concentrate from a separate container or tank through a pickup tube. The foam is then mixed with the water in the correct percentage (typically 1%, 3%, or 6%) downstream of the inductor.

This foam solution is essential for fighting flammable liquid fires (Class B), where it forms a blanket that smothers the fire and prevents re-ignition. In-line foam inductors are valued for their simplicity, reliability, and ability to convert a standard water hose line into a powerful foam capable system.