General Principle of Firefighting Foam
OperationÂ
Firefighting foam is made up of three components: a foam concentrate, water, and air. The concentrate is mixed with water at its specified proportion, creating a foaming solution (also called "premix"). Once aerated, this solution forms a stable foam composed of air-filled bubbles.
It acts on fires through:
Cooling: Lowers the temperature.
Separation: Prevents contact between fuel and oxygen.
Isolation: Forms a barrier to stop reignition.
Â
Depending on the type of foam concentrate, the proportion varies between 1% and 6% (e.g., a 3% foam = 3 liters of concentrate mixed with 97 liters of water).
Â
AdvantagesÂ
Thanks to its physical and chemical properties, firefighting foam provides several essential advantages for safe and effective extinguishment in high-risk environments:
Highly effective on liquid fires (Class B): Oil, gasoline, liquefied gas, etc.
Suitable for high industrial hazard scenarios
Low density: Floats on the surface of flammable liquids, limiting fire spread.
Tailored solutions: Ai Group helps you choose the most efficient, certified foam concentrate while minimizing environmental impact.
Expansion Ratio (Foam Expansion)
The expansion ratio is the ratio between the volume of foam produced and the volume of foaming solution used to generate it. The expansion depends heavily on the type of concentrate and the foam generator.
There are 3 types of expansion:
Low expansion: Ideal for surface (2D) fires such as storage tanks or bunds. This dense foam spreads rapidly and forms a tight sealing blanket. It can be projected over long distances using monitors or nozzles.
Â
Medium expansion: Used in smaller or enclosed spaces (solvent rooms, basements). Depending on its expansion ratio (20 to 200), it can protect plastic materials, tires, flammable liquids, pits, or wells.
Â
High expansion: With an expansion ratio above 200, it is designed to quickly fill large volumes such as warehouses or hangars. Produced by specialized generators, it efficiently floods large areas in minimal time.
Â
