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43 Cards in this Set
- Front
- Back
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What does a separating foam do? |
Creates a barrier between the fuel and the fire (967) |
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What does cooling foam do? |
Lowers the temperature of the fuel and adjacent exposures (967) |
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What does smothering foam do? |
Prevents air from reaching the fuel and mixing with vapors, reduces possibility or re ignition (967) |
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What does penetrating foam do? |
Lowers surface tension of water, allows to penetrate class A materials (967) |
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What is a foam concentrate? |
pure foam (968) |
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What is foam proportioner? |
Device that introduces foam concentrate into a water stream (968) |
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What is added in the process of aeration? |
Air (968) |
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Why is aeration needed? |
To produce an adequate amount of foam bubbles to form an effective foam blanket (968) |
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What is foam expansion? |
An increase in volume of a foam solution when it is aerated (968) |
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What does foam expansion depend on? |
Type of foam used, accurate proportioning, quality of the foam concentrate, method of aeration (968) |
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What are the three classifications of expansion |
Low, medium, and high expansion (969) |
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What is air/ solution on a low, medium and high expansion foam? |
20-1, 20-1 to 200-1, and 200-1 to 1000-1 (969) |
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What are low expansion foams effective at dealing with? |
They are effective at controlling and extinguishing most class B fires (969) |
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What are medium expansion foams used for? |
They are used to suppress vapours from hazmat spills (at between 30-1 to 55-1) (969) |
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Where are high expansion foams used? |
In confined spaces (969) |
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Class A foam is used when? |
On solid combustibles, it is very effective. (971) |
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Can Class A foam be used with fog nozzles? |
Yes (971) |
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When is Class B foams used? |
To extinguish flammable liquids. (971) |
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What is used to put out Hydrocarbon fuels, such as oil and gasoline? |
Class B foam (971) |
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What is used to put out Polar Solvents, such as alcohol, Acetone, Acids and Esters? |
Class B foam (972) |
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What two bases are Class B foams made of? |
Protein, or synthetic base (972) |
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What factors affect the minimum amount of foam that should be applied? |
Type of foam concentrate, whether the fuel is on fire, type of fuel, whether the fuel is spilled or contained, whether the foam is applied via fixed or portable equipment (972) |
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Once application of foam has began, do you stop? |
No, doing so may cause fire to to consume whatever blanket foam there is. (973) |
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Most firefighting foams are used at what percentage? |
94-99.9% Water (974) |
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Most Class A foams are mixed to what? |
1% or less (974) |
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Class B foams are mixed to what percent? |
1-6% (974) |
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What are new Multipurpose foams used at? |
3% (974) |
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The selection of a proportioner depends on? |
Foam solution available, water pressure, cost of the foam, intended use of the foam, foam agent to be used (974) |
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What are the four basic ways foam may be proportioned? |
Eduction, Injection, Batch mixing, premixing (975) |
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What is Eduction? |
Draws foam through a hose connected to the foam. Uses drafting principles. (975) |
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What is injection? |
Using an external pump or head pressure. (975) |
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What is Batch Mixing? |
Simplest method. Common with class A foams. |
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Disadvantages to Batch Mixing? |
Not effective at large incidents, must be mixed for a certain amount of time before use (977) |
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What is premixing? |
Commonly used, premeasured water and foam are mixed together. (977) |
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What are the three foam proportioning systems currently used? |
Portable, apparatus mounted, or compressed air foam systems (978) |
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What is an in line eductor? |
Most common foam proportioner used in the fire service. Designed to be directly attached to the pump panel. Uses drafting principle. Foam inlet should not be above 6 feet, or the foam will be lean (979) |
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What is a foam nozzle Eductor? |
Eductor built on same principle at in line eductor, however the eductor is built into the nozzle. (979) |
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Advantages of using Compressed Air Foam Supplies (CAFS) |
Stream reach is longer, lighter, foam is durable (981) |
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Disadvantages to CAFS? |
Expensive, creates a high nozzle reaction, additional training (981) |
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Does Smooth bore handline provide an effective fire stream? |
Yes, it provides a good reach. Often used with CAFS (981) |
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What do Fog nozzles do when spraying foam? |
Produce low expansion, short lasting foam. Work well with AFF. (981) |
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What is the most effective appliance for low expansion foam? |
Air Aspirating foam nozzle (982) |
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Do foam concentates pose a risk to firefighters? |
A minimal risk, mildly irritating to eyes and skin. (985) |
