Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
96 Cards in this Set
- Front
- Back
|
Prior to the second half of the twentieth century, foam fire fighting equipment and systems were primarily limited to where?
|
Shipboard, industrial, and airport fire protection.
|
|
|
What are the major reasons for the increased use of foam and durable agents in municipal and wildland firefighting in recent years?
|
-Magnitude and frequency of hazardous materials incidents
-New advances in foam concentrate technologies that have provided products which are more easily used. -Technological improvements in foam proportioning equipment and systems. |
|
|
What are the majority of foams used today?
|
Mechanical foams
|
|
|
What two things must be done to mechanical foams before they can be used?
|
proportioned and aerated
|
|
|
The raw foam liquid in its storage container before being combined with air and water.
|
Foam Concentrate
|
|
|
The device that introduces foam concentrate into the water stream to make a foam solution.
|
Foam Proportioner
|
|
|
The mixture of foam concentrate and water before the introduction of air.
|
Foam Solution
|
|
|
The complete product after air is introduced into the foam solution.
|
Foam(also known as finished foam)
|
|
|
Class B fuels are divided into what two categories?
|
-hydrocarbons
-polar solvents |
|
|
Modern fuel blends that include gasoline and 10%or more solvent additives should be handled as what in emergency operations?
|
polar solvents
|
|
|
Class B foams designed solely for hydrocarbon fires will not extinguish what type of fires, no matter what the concentration of the foam?
|
Polar solvent fires
|
|
|
What are the three methods by which foam extinguishes and/or prevents fire?
|
- Separating
- Cooling - Suppressing |
|
|
What does the selection of foam proportioning depend on?
|
- Foam solution flow requirements
- Available water pressure - Cost - Intended use - The agent to be used |
|
|
What are the four basic methods for proportioning foam?
|
- Induction
- Injection - Batch mixing - Premixing |
|
|
Method of proportioning foam that uses the pressure energy in the stream of water passed through a venturi device that drafts foam concentrate into a fire stream.
|
Induction
|
|
|
Method of proportioning foam that uses an external pump or head pressure to force foam concentrate into the fire stream at the correct ratio in comparison to the flow.
|
Injection
|
|
|
Simplest method of mixing an appropriate amount of foam concentrate by pouring it directly into a tank of water.
|
Batch mixing
|
|
|
Method where premeasured portions of water and foam concentrate are mixed in a container.
|
premixing
|
|
|
Foam pails contain how much concentrate?
|
5 gallons
|
|
|
Most common size containers of foam concentrate used by municipal fire departments.
|
Pails (5 gallons)
|
|
|
How many gallons does barrels or drums of foam concentrate contain?
|
55 gallons
|
|
|
How many gallons of foam concentrate do totes contain?
|
275 gallons
|
|
|
Foam concentrate tanks on municipal pumpers range from __-___gallons.
|
20-200 gallons
|
|
|
Foam pumpers and tenders may carry ____gallons or more concentrate.
|
8000 gallons
|
|
|
The bulk of mechanical foam concentrates are divided into what two general categories?
|
-Those intended for class A fuels
- Those intended for class B fuels |
|
|
Class A foam has been used since when?
|
1940's
|
|
|
What reduces the surface-tension of the water in the foam solution?
|
Hydrocarbon surfactants
|
|
|
Class A foam may be used with what types of nozzles?
|
- fog nozzles
- aerating foam nozzles - medium- and high-expansion devices - Compressed air systems |
|
|
What is the shelf life of class A foam?
|
As much as 20 years
|
|
|
Class A foam concentrates are mixed in what proportions?
|
0.1-1.0%
|
|
|
Foam concentrate percentage for fire attack and overhaul with standard fog nozzle?
|
0.2-1.0%
|
|
|
Foam concentrate percentage for exposure protection with standard fog nozzle?
|
0.5-1.0%
|
|
|
Foam concentrate percentage for any application with air aspirating foam nozzles?
|
0.3-0.7%
|
|
|
Foam concentrate percentage for any application with compressed air foam system (CAFS)?
|
0.2-0.5%
|
|
|
The minimum amount of foam solution that must be applied to a fire per minute, per square foot of fire.
|
Application rate
|
|
|
Foam that is very fluid and is desirable for areas requiring maximum penetration.
|
Wet foam
|
|
|
Foam that is a rigid coat that adheres well. Its slow drainage rate allows it to cling to these surfaces for extended periods.
|
Dry Foam
|
|
|
Foam that has the ability to blanket and wet the fuel equally well.
|
Medium Foam
|
|
|
Class B foams are manufactured from what two bases?
|
- Synthetic
- Protein |
|
|
Protein based class B foams are derived from what type of proteins?
|
Animal
|
|
|
Synthetic class B foams are made from a mixture of what?
|
Fluoro-surfactants
|
|
|
Protein-based foams have a shelf life of how long?
|
About 10 years
|
|
|
Synthetic based foams have a shelf life of generally how long?
|
20-25 years
|
|
|
In general, different manufacturer's foams should not be mixed together except for what kind?
|
Mil-specs
|
|
|
Generally what type of foams are safer for the environment?
|
Protein based foams
|
|
|
Today's class B foams are mixed in proportions from _%-_%
|
1%-6%
|
|
|
Class B foam concentrates are normally used at a _-_% concentration hydrocarbons and _-_% on polar solvents.
|
1-3% ; 3-6%
|
|
|
Older polar solvent mechanical foam concentrates were designed to be used at concentrates were designed to be used at what concentrations?
|
6% or greater
|
|
|
Medium-expansion foams are typically used at either _%, _%, or _% concentrations.
|
1 1/2%, 2%, or 3%
|
|
|
The increase in volume of a foam solution when it is aerated.
|
Foam Expansion
|
|
|
The method of aerating a foam solution results in varying degrees of expansion depends on what factors?
|
- Type of foam
- Accurate proportioning of the foam concentrate solution. - Quality of foam. - Method of aspiration |
|
|
Standard for low-, medium-, and high-expansion foam.
|
NFPA 11
|
|
|
NFPA 11 states that low-expansion foam has an air solution ratio of what?
|
20:1
|
|
|
NFPA 11 states that medium-expansion foam has an air solution ratio of what?
|
20:1-200:1
|
|
|
NFPA 11 states that high-expansion foam has an air solution ratio of what?
|
200:1-1000:1
|
|
|
Once foam application has started, it should be continued uninterrupted until when?
|
extinguishment is complete
|
|
|
Alcohol-resistant fluoroprotein foam maintains its alcohol resistive properties for how long?
|
15 minutes
|
|
|
What is the most commonly used foam today?
|
AFFF
|
|
|
What does AFFF stand for?
|
Aqueous Film Forming Foam
|
|
|
High expansion foams are special-purpose foams that have what kind of base?
|
A detergent base
|
|
|
High expansion foams have what three basic applications?
|
- In concealed spaces
- In fixed extinguishing systems - In class A fire applications |
|
|
Foam proportioning devices operate by one of what two basic principles?
|
- The pressure of the water stream flowing through a restricted orifice creates a venturi action that inducts foam concentrate into the water stream.
- Pressurized proportioning devices inject foam concentrate into the water stream at a desired ratio and at a higher pressure than that of the water. |
|
|
The three common types of portable foam proportioners are what?
|
- In-line foam eductors
- Foam nozzle eductors - Self-educting master stream nozzles |
|
|
In order for the nozzle and eductor to operate properly, both must have the same what?
|
GPM rating
|
|
|
Self-educting master stream foam nozzle is used in excess of ___gpm.
|
350 gpm
|
|
|
The jet ratio controller is a type of in-line eductor that allows the foam concentrate supply to be as far away as ____ft from the self-educting master stream foam nozzle.
|
3000 ft
|
|
|
The Jet ratio controller allows an elevation change of up to __ft.
|
50 ft
|
|
|
The flow of water to the jet ratio controller represents what percent of the total flow in the system?
|
2.5%
|
|
|
What percentage solution does the jet ratio controller supply to the self-educting master stream nozzle?
|
66%
|
|
|
What are the most commonly used eductors to proportion class B foams?
|
in-line eductors
|
|
|
One of the most common types of built in proportioners installed in mobile fire apparatus today.
|
Around-the-pump proportioners
|
|
|
What are the disadvantages of around-the-pump proportioners?
|
- On older proportioners if the inlet water supply is greater than 10psi the concentrate will not enter the pump.
- Does not allow plain water and foam to be discharged from the pump at the same time. - When lines are shut down water can still circulate through the eductor adding more concentrate than needed. |
|
|
What are the advantages to Variable-flow Variable-rate Direct Injection Systems?
|
-Ability to proportion at any flow rate or pressure within design limits.
- System automatically adjusts to changes in water flow. - Nozzles may be either above or below the pump without affecting the proportioning. - System may be used with high-energy foam systems. |
|
|
In this system, a variable-speed mechanism, which is either hydraulically or electrically controlled, drives a foam concentrate pump. The foam concentrate pump supplies a venturi-type proportioning device built into a water line. When activated, the foam concentrate pump output is automatically monitored so that the flow is commensurate with the flow of water to produce an effective foam solution.
|
Variable-flow Demand-type Balanced Pressure Proportioners
|
|
|
Class A foam solutions do not retain their foam properties if mixed in the water for more than how long?
|
24 hours
|
|
|
These systems introduce compressed air into the foam solution prior to discharge into the hoseline. The turbulence of the foam solution and compressed air going through the piping and/or hoseline creates finished foam.
|
High-energy Foam Generating Systems
|
|
|
In general when using CAFS, 2cfm of airflow per gallon per minute of foam solution flow produces a very dry foam at flows of up to ___gpm of foam solution.
|
100 gpm
|
|
|
Foam expansion ratios for fog nozzles are what?
|
2:1 - 4:1
|
|
|
What are the techniques for applying foam to a liquid fuel fire?
|
- Direct application
- Roll-on method - Bank-down method - Rain-down method |
|
|
Durable Agents can also be called what?
|
- Gelling Agents
- Fire Blocking Gels - Aqueous Fire Fighting Gels |
|
|
One of the most common types of built in proportioners installed in mobile fire apparatus today.
|
Around-the-pump proportioners
|
|
|
What are the disadvantages of around-the-pump proportioners?
|
- On older proportioners if the inlet water supply is greater than 10psi the concentrate will not enter the pump.
- Des not allow plain water and foam to be discharged from the pump at the same time. - When lines are shut down water can still circulate through the eductor adding more concentrate than needed. |
|
|
What are the advantages to Variable-flow Variable-rate Direct Injection Systems?
|
-Ability to proportion at any flow rate or pressure within design limits.
- System automatically adjusts to changes in water flow. - Nozzles may be either above or below the pump without affecting the proportioning. - System may be used with high-energy foam systems. |
|
|
In this system, a variable-speed mechanism, which is either hydraulically or electrically controlled, drives a foam concentrate pump. The foam concentrate pump supplies a venturi-type proportioning device built into a water line. When activated, the foam concentrate pump output is automatically monitored so that the flow is commensurate with the flow of water to produce an effective foam solution.
|
Variable-flow Demand-type Balanced Pressure Proportioners
|
|
|
Class A foam solutions do not retain their foam properties if mixed in the water for more than how long?
|
24 hours
|
|
|
These systems introduce compressed air into the foam solution prior to discharge into the hoseline. The turbulence of the foam solution and compressed air going through the piping and/or hoseline creates finished foam.
|
High-energy Foam Generating Systems
|
|
|
In general when using CAFS, 2cfm of airflow per gallon per minute of foam solution flow produces a very dry foam at flows of up to ___gpm of foam solution.
|
100 gpm
|
|
|
Foam expansion ratios for fog nozzles are what?
|
2:1 - 4:1
|
|
|
What are the techniques for applying foam to a liquid fuel fire?
|
- Direct application
- Roll-on method - Bank-down method - Rain-down method |
|
|
Durable Agents can also be called what?
|
- Gelling Agents
- Fire Blocking Gels - Aqueous Fire Fighting Gels |
|
|
Chemically, what are Durable Agents?
|
Water-absorbant Polymers
|
|
|
What is the major differences between durable agents and class A foams?
|
- Considerably more expensive
- Make surfaces they are applied to very slippery - If applied to a structure they can be rehydrated with a fine mist to extend their protection for several days. |
|
|
Durable agents are applied at what percentage solution?
|
1%
|
|
|
Durable agents are applied at what percentage for line construction?
|
1.5-2%
|
|
|
Durable agents are applied at what percentage for construction protection?
|
2-3%
|
|
|
Durable agents will adhere vertical surfaces for as much as how long?
|
24 hours
|
