Class A & B Foam Flashcards
In which instance would the application of Class B Foam be most appropriate to help with fire suppression?
A fire involving any type of flammable liquid where blanketing and smothering for vapour suppression is of the first importance.
What is the appropriate Foam Educator setting for a deep hydrocarbon spill (+1 inch depth)
3%
What is the appropriate Foam Eductor setting for a Polar Solvent spill?
3%
What is the appropriate Foam Eductor setting for a shallow hydrocarbon spill (-1 inch depth)?
1%
In regards to foam application, what is the definition of the roll on method?
Used when the other methods are not feasible due to the elevation or nature of the fuel container.
An example is an above-ground storage tank fire. Stream is directed above the fire, and foam is allowed to rain down onto the surface of the fuel. The operator sweeps the stream back and forth to ensure the entire surface is covered until the fuel is completely covered.
Class B foam solutions are conductive and are NOT recommended for use on electrical fires or in the vicinity of charged electrical lines.
True
How does foam help to extinguish and/or prevent the ignition of Class B materials?
Separating, cooling, suppressing.
In regards to foam application, what is the definition of the Rain-Down Method?
Used when the other methods are not feasible due to the elevation or nature of the fuel container. An example is an above-ground storage tank fire. Stream is directed above the fire, and foam is allowed to rain down onto the surface of the fuel. The operator sweeps the stream back and forth to ensure the entire surface is covered until the fuel is completely covered.
What is slug flow?
When the firefighter on the nozzle end is not opening the nozzle fully, resulting is less water flow.
When the pump discharge pressure is too low and the water isn’t moving fast enough.
When the foam solution is not rich enough or unevenly mixes with air, inadequate mixing occurs sending pockets or slugs of water and air to the nozzle.
What are the four aspects of the Foam
Tetrahedron?
Water, air, foam concentrate, mechanical agitation
In regards to foam application, what is the definition of the bank down method?
Used when a vertical surface is available near or within the area of ignitable liquid. The foam stream is directed onto the vertical surface allowing the finished foam to run down and spread across the surface of the fuel.
