If your business manufactures, stores, or transports flammable liquids, a foam fire suppression system may be the appropriate fire suppression system to fit your needs. Foam systems are also used in the protection of power generation (coal bunkers), tire and rubber factories, lumber mills, paper warehouses, and have been recognized as very effective fire suppression agents for subsurface injection into hydrocarbon fuel storage tanks.
Firefighting foam is made of three ingredients - a foam concentrate, water, and air. The concentrate is mixed with water (proportioning), creating a foam solution. That solution is mixed with air (aspirated) to produce the foam, which is very fluid, readily flowing over liquid surfaces. The foam itself is a stable mass of small, air-filled bubbles with a lower density that oil, gasoline, or water.
Balanced pressure proportioning is the most common method used for foam system applications. The foam concentrate pressure is balanced with the water pressure at the proportioner inlet allowing the proper amount of foam concentrate to be metered into the water stream.
With an aspirating discharge device, foam solution passes through an orifice, past air inlets, and into an expansion area to produce expanded foam. In non-aspirating devices, the foam solution doesn't mix with air until it first passes through the orifice and discharge outlet.
Firefighting foam agents suppress fire by separating the liquid fuel from the air (oxygen) it needs to burn. Depending on the type of foam agent, this is done in one of several ways;
the foam blankets the fuel surface, smothering the fire and separating the flames from the fuel surface
the foam cools the fuel and adjacent heat and ignition surfaces
the foam suppresses the release of flammable vapors that can mix with air.
Benefits of foam fire suppression agents are; minimal water damage to structure or contents
hazardous run-off is reduced compared to sprinkler systems requiring large volumes of water