Chapter 14 - Foam Equipment and Systems Flashcards
____________ foams are the most common foams in use. These products must be ___________ (mixed with water) and _______ (mixed with air) before use.
Mechanical / proportioned / aerated
p 480
- Foam produced by a physical agitation of a mixture of foam concentrates, water, and air.
Mechanical Foam
p 480
- Mixing of water with an appropriate amount of foam concentrate in order to form a foam solution.
Proportioning
p 480
- Introduction of air into a foam solution to create bubbles that result in finished foam.
Aeration
p 480
To produce fire fighting foam, foam concentrate, water, and air must be _________ or injected in the correct ratios.
educted
p 480
- Process used to mix foam concentrate with water in a nozzle or proportioner; concentrate is drawn into the water stream by the Venturi method.
Eduction
p 480
- Raw foam liquid in its storage container before being combined with water and air.
Foam concentrate
p 480
- Device that injects the correct amount of foam concentrate into the water stream to make foam solution.
Foam proportioner
p 480
- Mixture of foam concentrate and water before the introduction of air.
Foam solution
p 480
- Completed product after air is introduced into the foam solution.
Foam
Also known as finished foam
p 480
Class B fuels are divided into two categories; _______________ and ________ __________.
hydrocarbons and polar solvents
p 480
Fuels such as crude oil, fuel oil, gasoline, benzene, and kerosene are what type of class B fuels?
Hydrocarbons
p 480
Hydrocarbon fuels such as crude oil, fuel oil, gasoline, benzene, and kerosene, are _____________ based and have a specific gravity ?
petroleum based
less than one (water being considered equal to one) and will float on water
p 480
Class B foam is effective in extinguishing hydrocarbon fuel fires and suppressing vapors because it ?
floats on the surface of hydrocarbon fuels
p 480
Fuels such as alcohol, acetone, ketones, and esters are what type of class B fuels ?
Polar solvents
p 480
Polar solvent fuels, such as alcohol, acetone, ketones, and esters, are know as _________ liquids because they mix with water.
miscible
p 480
Many modern fuels, including gasoline, are blended with up to 15 percent ________ additives. Treat these products as ________ _________ during emergency operations.
solvent / polar solvents
p 480
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
p 481
- A petroleum based organic compound that contains only hydrogen and carbon.
Hydrocarbon Fuel
p 481
- 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.
Polar Solvents
p 481
- Materials that are capable of being mixed in all proportions.
Miscible
p 481
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.
- Separating
- Cooling
- Suppressing or smothering
p 481
______________ is the act of mixing water with foam concentrate to form a solution.
Proportioning
p 482
Most fire fighting foam concentrates are formulated to mix with ______ to _____ percent water.
94 to 99.9
p 482
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
p 482
Foam is proportioned using one of four basic methods:
- __________
- _________
- _______ ________
- ___________
- Induction
- Injection
- Batch Mixing
- Premixing
p 482-483
The ___________ method of proportioning foam uses the pressure of a water stream to induct (draft) foam concentrate into the fire stream.
induction method
p 483
Induction
This is achieved by passing the stream of water through a Venturi device called an __________.
eductor
p 483
Induction
A _________ ______ connected to the eductor is inserted into the foam concentrate container.
pickup tube
p 483
- Portable proportioning device that injects a liquid, such as foam concentrate, into the water flowing through a hoseline or pipe. (2) Venturi device that uses water pressure to draw foam concentrate into a water stream for mixing; also enables a pump to draw water from an auxiliary source.
Eductor
p 483
- Solid or flexible tube used to transfer foam concentrate from a storage container to the inline eductor or proportioner.
Pickup Tube
p 483
The ________ method of proportioning foam uses an external pump to force foam concentrate into the fire stream at the proper ratio in comparison to the flow.
injection
p 483
A simple but potentially inaccurate method of mixing foam concentrate and water, _______ _________ occurs when an appropriate amount of foam concentrate is poured directly into a tank of water.
batch mixing
p 483
Batch mixing is commonly used with Class ___ foam.
Class A
p 483
____________ is a common method of proportioning in which pre-measured portions of water and foam concentrate are mixed in a container.
Premixing
p 484
Five-gallon plastic ______ are commonly used containers in many municipal fire departments.
pails
p 485
Foam concentrate is also available in ____-gallon plastic or plastic-lined barrels.
55 gallon
p 485
When bulk storage of foam concentrate is required, some fire departments or industrial facilities may specify _____ gallon containers, called ______.
275 gallons / totes
p 485
Foam concentrate tanks on municipal fire apparatus generally range from ____ to _____ gallons while foam pumper or tenders may carry ________ gallons or more of concentrate.
20 to 200 / 8000
p 485
Regardless of the type of tank, foam storage must be ________.
airtight
p 486
The majority of foam concentrate are divided for use on either Class A (__________ ____________) or Class B (___________ ________) fuels.
ordinary combustibles / flammable liquids
p 486
The formula of Class A foam includes hydrocarbon ___________ that reduce the surface tension of water in the foam solution. This reduced surface tension allows for better ___________ and increased effectiveness.
surfactants / penetration
p 487
- Chemical that lowers the surface tension of a liquid; allows water to spread more rapidly over the surface of Class A fuels and penetrate organic fuels.
Surfactant
p 487
Proportioning - Class A foam
________ time increases in proportion with increases in the percentage of the solution.
Drain time
p 487
Proportioning - Class A foam
- Fire attack and overhaul with standard fog nozzles - ___ to ___ percent concentrate
- Exposure protection with standard fog nozzles - ____ to ____ percent concentrate
- Any application with air aspirating foam nozzles - ____ to ____ percent concentrate
- Any application with CAFS - ____ to ____ percent concentrate
- 0.2 to 0.5
- 0.5 to 1.0
- 0.3 to 0.7
- 0.2 to 0.5
p 488
Most foam nozzles will produce more stable foam at ____ percent concentrate than at ____ percent concentrate.
1.0 / 0.5
p 487
The ___________ ______ refers to the minimum amount of foam solution that must be applied to a fire, per minute, per square foot of fire.
application rate
p 488
The application rate for Class A foam is the same as the minimum required flow rate for ?
water
p 488
Application of Class A foam:
- Areas that require maximum penetration. ______ foam is very fluid and will easily penetrate Class A fuels
- Vertical surfaces. ______ foam forms a rigid coating that adheres well. It is slow to _______, allowing the foam to cling to a vertical surface for extended periods.
- Surface of a fuel. Foam must have the ability to _______ and ___________ the surface of a fuel. __________ foam is able to penetrate a fuel while maintaining a sufficient blanket of protection.
- wet
- dry / drain
- cling and penetrate / medium
p 488
The _______ time for foam also plays a major role in the effectiveness of the product.
drain
p 488
Class ___ foam is applied to suppress fires involving flammable and combustible liquids. It is also used to suppress _______ from unignited spills involving the liquids.
Class B / vapors
p 488