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.
- 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.
- Solid or flexible tube used to transfer foam concentrate from a storage container to the inline eductor or proportioner.
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.
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 is commonly used with Class ___ foam.
____________ is a common method of proportioning in which pre-measured portions of water and foam concentrate are mixed in a container.
Five-gallon plastic ______ are commonly used containers in many municipal fire departments.
Foam concentrate is also available in ____-gallon plastic or plastic-lined barrels.
When bulk storage of foam concentrate is required, some fire departments or industrial facilities may specify _____ gallon containers, called ______.
275 gallons / totes
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
Regardless of the type of tank, foam storage must be ________.
The majority of foam concentrate are divided for use on either Class A (__________ ____________) or Class B (___________ ________) fuels.
ordinary combustibles / flammable liquids
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
- 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.
Proportioning - Class A foam
________ time increases in proportion with increases in the percentage of the solution.
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
Most foam nozzles will produce more stable foam at ____ percent concentrate than at ____ percent concentrate.
1.0 / 0.5
The ___________ ______ refers to the minimum amount of foam solution that must be applied to a fire, per minute, per square foot of fire.
The application rate for Class A foam is the same as the minimum required flow rate for ?
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.
* dry / drain
* cling and penetrate / medium
The _______ time for foam also plays a major role in the effectiveness of the product.
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
Class B foam concentrates consist of a _________ or ________ base.
synthetic or protein base
While synthetic foam is made of a mixture of _______________, protein based foam is derived from __________ protein.
fluorosurfactants / animal
Class B foam concentrates should be stored in cool areas to maximize shelf life: approximately ____ years for protein based foams and _____ to _____ years for synthetic foam.
10 years / 20 to 25 years
Foam concentrates of the same type, which are manufactured to ____ __________ specifications, may be mixed at any time with no adverse effects.
Class B foams are mixed in proportions from _____ to _____ percent.
one to six
The concentration for hydrocarbon fuels is normally _____ to ______ percent, while _______ or ______ percent is used for polar solvents, based on the manufacturers recommendations.
one to three / three to six
_______ ___________ is the increase in volume of foam solution once it has been aerated.
Foam expansion is generally described as being ?
low, medium, or high
NFPA ____ states that low expansion foam contains an air/solution ratio of up to ____ parts finished foam for every part of foam solution, a _____ ratio.
11 / 20 / 20:1
Medium expansion foam is commonly used at a rate of _____ up to _______ through hydraulically operated nozzle type delivery devices. When high expansion foam is used the expansion rate is from _______ to _______.
20:1 up to 200:1 / 200:1 up to 1000:1
The minimum foam solution application rates for ignited fuels are specified in NFPA _____.
In order to calculate the application rate available from a specific nozzle, divide the ______ ______ by the ______ of the fire.
flow rate / area
ex. 250 gpm nozzle on a 1000 square foot fire equals a rate of 0.25 gpm/ft^2
__________ spills do not require the same application rate due to the absence of radiant heat, open flame, and thermal drafts.
Once you begin application, it should continue without interruption from an __________ and ________ position until extinguishment is complete.
uphill and upwind
Protein foams are derived from animal protein sources such as ________, _______, or ________ meal.
hooves, horns, or feather meal
Regular protein foams
These sources are __________ in the presence of lime and converted to a protein hydrolysate that is neutralized.
Regular protein foam generally has a good heat stability and ___________ resistance.
- To cause or undergo a chemical process of decomposition involving the splitting of a bond and the addition of the element of water.
- Ability of a foam blanket to resist direct flame impingement such as would be evident in a partially extinguished petroleum fire.
______________ foam, a combination of protein-based foam and synthetic foam, contains protein concentrate to which fluorochemical surfactants are added.
What concentrate is based on the technology of fluoroprotein foam for long lasting heat resistance and capabilities of aqueous film forming foam (AFFF) for quick knockdown ?
Film forming fluoroprotein foam (FFFP)
What foam commonly called A triple F, is currently the most commonly used synthetic foam concentrate ?
Aqueous film forming foam
- Synthetic foam concentrate that when combined with water can form a complete vapor barrier over fuel spills and fires and is a highly effective extinguishing and blanketing agent on hydrocarbon fuels.
Aqueous Film Forming Foam (AFFF)
__________ ___________ AFFF concentrate is commonly available for use on polar solvents.
When AR-AFFF foam is applied to polar solvent fuels, a ___________ is created over the fuel. This _________ separates the water in the foam blanket from effects of the solvent.
membrane / membrane
______-____________ foam contains a detergent base and low water content. The low water content provides less _________ and minimizes water _________.
High-expansion / runoff / damage
In general, foam proportioning devices operate by one of two basic principals:
* A __________ effect created by the presence of a water stream flowing through a restricted orifice inducts (drafts) foam concentrate into the water system.
* A _____________ _____________ device injects foam concentrate into a water stream at a set ratio and at a higher pressure than the water flow.
Venturi / pressurized proportioning
What are the three common types of portable foam proportioners ?
in-line foam eductor / foam nozzle eductors / self enducting master stream nozzles
- Type of foam delivery device that is located in the water supply line near the nozzle. The foam concentrate is drawn into the water line using the Venturi method.
In-Line Foam Eductor
In-line foam eductors
* The pressure at the discharge side of the eductor must not exceed _____ percent of the eductor inlet pressure. This ______ __________ is determined by adding the nozzle pressure, friction loss in the hose between the eductor and the nozzle and elevation pressure.
70 / back pressure
- Pressure loss or gain created by changes in elevation between the nozzle and pump.
In-line foam eductors:
* The foam concentrate inlet to the eductor should be no more than _____ feet above the liquid surface of the foam concentrate.
In-line foam eductors
* Viscosity, or the thickness and ability of a liquid to flow freely, is affected by ____________. Foam concentrates become more viscous in ______ temperatures and less viscous when ________.
temperature / cold / heated
In-line foam eductors:
The nozzle and eductor must have the same _____ rating in order to operate successfully.
A _____ _________ eductor operates under the same principle as an in-line eductor. The eductor is built into the _____-_________ nozzle rather than attached to the hoseline.
foam nozzle / self-enducting nozzle
- Large capacity nozzle with built-in foam eductor.
Self-Educting Master Stream Foam Nozzle
A ______ ________ controller is a type of in-line eductor that may be used to supply foam concentrate to a self enducting master stream. It allows the foam concentrate supply to be located as far as _______ feet away from a self-educting master stream nozzle.
jet ratio / 3000 feet
- Type of foam eductor that is used to supply self-enducting master stream nozzles; may be located at distances up to 3000 feet from the nozzle.
Jet Ratio Controller (JRC)
What is the only difference in installed in-line eductors and portable in-line eductors ?
The fixed mounting position of an installed in line eductor
Installed in-line eductor systems
In some installations a _________ proportioner is installed to reduce the friction loss across the eductor when no foam is desired.
Installed in-line eductors are most commonly used to proportion Class ____ foam. Installed in-line foam eductors are generally not effective for proportioning the very low concentrations used in Class ____ foam operations.
Class B / Class A
_________-____-______ proportioners are one of the most common types of installed proportioners used in modern fire apparatus.
Around the pump
- Apparatus mounted foam proportioner in which a small quantity of water is diverted from the apparatus pump through an inline proportioner; there it picks up the foam concentrate and carries it to the intake side of the pump. It is the most common apparatus mounted foam proportioner in service.
Around the pump proportioner
Around the pump proportioners
An inline eductor is installed in this line with a valve controlling the flow of water passing through it. In the open position the valve allows approximately ____ to ____ gpm to flow through the piping.
10 to 40 gpm
The _______ - _____ __________ ___________ proportioner, used on large mobile apparatus installations, such as ARFF vehicles, is one of the most accurate methods of foam proportioning.
bypass-type balanced pressure proportioner
- Foam concentrate proportioner that operates in tandem with a fire water pump to ensure proper foam concentrate-to-water mixture.
Bypass-Type Balanced Pressure Proportioner
In addition the bypass type balanced proportioner has the ability to allow ______ to discharge from some outlets and plain _______ from others simultaneously.
foam / water
- Apparatus mounted foam system that injects the correct amount of foam into the pump piping, thereby supply all discharges with foam. The system automatically monitors the operation of the hoselines and maintains a consistent quantity of foam solution.
Variable-Flow Variable-Rate Direct Injection System
Variable flow variable rate direct injection systems proportion foam concentrate at rates from ____ to _____ percent.
0.1 to 3 percent
Variable flow variable rate direct injection systems may be employed with all Class ___ and many Class ___ foam concentrates. However, this type of system is not useable with _________ __________ foam concentrates due to the viscous (thick) nature of the product.
Class A / Class B / alcohol resistant
- Foam proportioning system that is used in both fixed and mobile applications; a variable speed mechanism drives the foam pump and automatically monitors the flow to produce an effective foam solution.
Variable-Flow Demand-Type Balanced-Pressure Proportioner
________ ________ or the ______ ____ method is the simplest method of proportioning foam.
Batch mixing or dump in
Generally batch mixing is only used with Class ___ foam concentrates and regular AFFF concentrates (not alcohol resistant).
Class A foam solutions do not retain their foaming properties when mixed in water for more than ____ hours, making pre-mixing virtually impossible.
______ _________ systems differ from other methods in that they introduce compressed air into the foam solution prior to discharge into a hoseline.
In addition to forming the foam, the compressed air allows the stream to be discharged to ________ _________ than an ordinary foam or water fire stream.
* Foam produced by a CAFS adheres to a fuel surface and resists heat longer than ?
low energy foam
* Hoselines containing high energy foam solution _______ less than those containing plain water, or low energy foam solution.
Due to the low eduction rates, a variable flow rate sensing proportioner is required to supply the fire stream at the rate of ____ to _____ percent.
0.1 to 1.0 percent
Generally, ____ cubic feet per minute of airflow per gallon per minute of foam solution produces a dry foam up to _____ gpm of foam solution.
2 / 100
Most structural and wildland suppression operations conducted with CAFS use an airflow rate of ____ to ____ cubic foot per minute of foam solution.
0.5 to 1.0
- Any nozzle that can be safely handled by one to three firefighters and flow less than 350 gpm.
The use of ________ ______ nozzles is limited to the application of Class A foam from a CAFS.
Firefighters may operate _______ flow, _________ flow, or __________ fog nozzles when applying low expansion, short duration foam blanket.
fixed / selective / automatic
Expansion ratios for most fog nozzles are ____ up to ____ range.
2:1 up to 4:1
Their most effective usage is during the application of regular ______ and Class ___ foam.
AFFF and Class A
Air-aspirating foam nozzles can be used with Class ____ foam in wildland fire fighting applications, and are the only nozzles that should be used with _________ and ____________ concentrates.
Class A / protein and fluoroprotein
Large scale flammable and combustible liquid fires often require the delivery of an amount of foam that is beyond the capability of the ____________. Like handline nozzles, fixed flow or automatic fog _______ ________ appliances may be used to deliver foam.
handlines / master stream
There are two basic types of medium- and high-expansion foam generators: ?
water aspirating and mechanical blower
The air content of medium expansion foam ranges from _____ to ______. For high expansion foam, the ratio ranges from ______ to _______.
20:1 to 200:1 / 200:1 to 1000:1
- High expansion foam generator that uses a fan to inject the air into the foam solution as it passes through the unit.
The _______ ___________ method of fire attack with Class A foam consists of applying finished foam directly onto the burning material.
A method for Class B foam application, the ____-____ _________ involves directing a foam fire stream on the ground near the front edge of a burning liquid spill.
Another method employed with Class B foam when a vertical surface is near or within a pool of ignitable liquid is the ?
bank down method
This is the most common method of foam application for above ground storage tank fires ?
No foam concentrates, solutions, or finished foam should be discharged into any ?
body of water