Foam Flashcards
What is firefighting foam primarily used for?
Suppressing fires by forming a barrier between the fuel and the air.
Name two common types of firefighting foam.
Aqueous Film Forming Foam (AFFF) and Alcohol-Resistant Aqueous Film Forming Foam (AR-AFFF).
What class of fires is Class A foam designed for?
Fires involving ordinary combustibles like wood, paper, and cloth.
What class of fires is Class B foam designed for?
Fires involving flammable liquids like gasoline and oil.
What does AFFF stand for?
Aqueous Film Forming Foam.
What is the primary function of firefighting foam?
To cool the fire and coat the fuel, preventing its contact with oxygen.
What is the typical concentration percentage for AFFF when mixed with water?
3% or 6%.
What does AR-AFFF stand for?
Alcohol-Resistant Aqueous Film Forming Foam.
Why is AR-AFFF used on polar solvent fires?
It resists breakdown when in contact with water-miscible fuels like alcohols.
What is the expansion ratio in firefighting foam?
The ratio of the volume of foam produced to the volume of the original foam solution.
What is a low-expansion foam?
Foam with an expansion ratio less than 20:1.
What is a high-expansion foam?
Foam with an expansion ratio greater than 200:1.
What is the roll-on method of foam application?
Applying foam by rolling it onto the surface of the burning liquid.
What is the bank-down method of foam application?
Applying foam by banking it off a vertical surface to gently flow onto the fire.
What is the rain-down method of foam application?
Applying foam by spraying it into the air, allowing it to fall gently onto the fire.
What does the term ‘foam blanket’ refer to?
The layer of foam that covers and suppresses a fire.
Why is it important to avoid plunging the foam stream directly into the fuel?
It can cause the fuel to splash and spread the fire.
What is the purpose of a foam proportioner?
To mix the correct amount of foam concentrate with water.
What is a foam eductor?
A device that uses the Venturi principle to introduce foam concentrate into a water stream.
What is the typical shelf life of most firefighting foam concentrates?
10 to 25 years, depending on the type and storage conditions.
What is fluorine-free foam (F3)?
Foam that does not contain fluorinated surfactants, designed to be more environmentally friendly.
What is the function of surfactants in firefighting foam?
To reduce surface tension, allowing the foam to spread over the fuel surface.
What is the significance of foam stability?
It determines how long the foam blanket will last before breaking down.
How does foam application rate affect fire suppression?
Insufficient application rates may fail to extinguish the fire, while excessive rates can waste resources.