Flashcards in Chapter 14 - Foam Equipment and Systems Deck (128)
____________ foams are the most common foams in use. These products must be ___________ (mixed with water) and _______ (mixed with air) before use.
Mechanical / proportioned / aerated
- Foam produced by a physical agitation of a mixture of foam concentrates, water, and air.
- Mixing of water with an appropriate amount of foam concentrate in order to form a foam solution.
- Introduction of air into a foam solution to create bubbles that result in finished foam.
To produce fire fighting foam, foam concentrate, water, and air must be _________ or injected in the correct ratios.
- Process used to mix foam concentrate with water in a nozzle or proportioner; concentrate is drawn into the water stream by the Venturi method.
- Raw foam liquid in its storage container before being combined with water and air.
- Device that injects the correct amount of foam concentrate into the water stream to make foam solution.
- Mixture of foam concentrate and water before the introduction of air.
- Completed product after air is introduced into the foam solution.
Also known as finished foam
Class B fuels are divided into two categories; _______________ and ________ __________.
hydrocarbons and polar solvents
Fuels such as crude oil, fuel oil, gasoline, benzene, and kerosene are what type of class B fuels?
Hydrocarbon fuels such as crude oil, fuel oil, gasoline, benzene, and kerosene, are _____________ based and have a specific gravity ?
less than one (water being considered equal to one) and will float on water
Class B foam is effective in extinguishing hydrocarbon fuel fires and suppressing vapors because it ?
floats on the surface of hydrocarbon fuels
Fuels such as alcohol, acetone, ketones, and esters are what type of class B fuels ?
Polar solvent fuels, such as alcohol, acetone, ketones, and esters, are know as _________ liquids because they mix with water.
Many modern fuels, including gasoline, are blended with up to 15 percent ________ additives. Treat these products as ________ _________ during emergency operations.
solvent / polar solvents
What foams are designed solely for use on hydrocarbon fuels and are not effective on polar solvent products regardless of the concentration that is applied ?
Class B foams
- A petroleum based organic compound that contains only hydrogen and carbon.
- Liquid having a molecule where the positive and negative charges are permanently separated, resulting in their ability to ionize in solution and create electrical conductivity. Water, alcohol and sulfuric acid are examples.
- Materials that are capable of being mixed in all proportions.
How foam works:
Foam extinguishes and/or suppresses vapors by the following methods
* ____________ - Creates a barrier between the fuel and the fire
* _________ - Lowers the temperature of the fuel and adjacent surfaces
* ____________ or ___________ - Prevents the release of flammable vapors, reducing the possibility of ignition or reignition.
* Suppressing or smothering
______________ is the act of mixing water with foam concentrate to form a solution.
Most fire fighting foam concentrates are formulated to mix with ______ to _____ percent water.
94 to 99.9
Class A foams are formulated to be proportioned within certain limits established by the manufacturer to achieve specific objectives. These percentages may range from as little as ____ percent to ___ percent.
0.1 to 1 percent
Foam is proportioned using one of four basic methods:
* _______ ________
* Batch Mixing
The ___________ method of proportioning foam uses the pressure of a water stream to induct (draft) foam concentrate into the fire stream.
This is achieved by passing the stream of water through a Venturi device called an __________.
A _________ ______ connected to the eductor is inserted into the foam concentrate container.