The firefighting foam system is made with three ingredients which include foam concentrate, air and water. When these three ingredients are mixed, it creates a foam solution. It is a stable mass of small bubbles filled with air and has a lower density than water, oil or gasoline. Such a unique combination of foam concentrate solution helps suppress and cool burning fuels, hot surfaces and flammable vapours.
Each type of foam concentrate has specific features, applications and benefits. Let’s find out the features of foam concentrate in a fire protection system.
Various features of the foam system
Class ‘A’ Foam agents :-
Class ‘A’ foam agents are formulated through fluorine-free surfactants to decrease the water surface tension by forming a clinging blanket. The formation of a clinging blanket helps in suppressing the combustible vapour while cooling or bringing down the temperature of the fuel. This foam immediately cools, insulates and wets a fire when applied on the ground or through air. This foam system effectively fights fires in power generation, coal mines, rubber factories, paper warehouses and timber mills.
Class ‘B’ Foam agents
This foaming agent is employed to fire incidents involving petroleum-based products and combustible liquids such as LNG.
Synthetic foams :-
This foam system is a detergent-based high-expansion foam concentrate system applied to large areas like warehouses, aircraft maintenance hangars, and ship cargo holds through air aspirating generators.
Protein foams :-
These foams produce stable mechanical foam with a 3% concentration and good expansion properties apart from having the characteristics of burn back resistance. This system is ideal for ensuring protection from the combustible and flammable liquid.
Fluroprotein foams :-
Fluroprotein foams provide significant extinguishment and control to suppress fire through greater fluidity and superior resistance to fuel combustion. It has been widely used for hydrocarbon vapour suppression. This is also one of the most effective agents for injecting sub-surface into storing hydrocarbon fuel tanks.