IFSTA ARFF 6th: Ch. 7 Flashcards
Extinguishing Agents
High expansion foam has an air/solution ratio of what?
A range 200:1 to 1000:1
Low expansion foam has an air/solution ratio of what?
20:1
What are the situations where complementary agents can be used as the primary agent on a fire?
Wheel Wells
Engine Nacelles
Interior Walls
Compartments
How often does the FAA recommend foam systems to be tested?
at least twice a year
What two types of gas do extinguishers use?
Nitrogen or CO2
How much foam does a Barrel (drum) hold?
55 gal
What is the most commonly used extinguishing agent in the fire service?
Water
What is the most common type of foam proportioner?
In line foam eductor
Stored pressure extinguishers contain a constant pressure of what?
200psi
What will happen if the nozzle has a flow rating lower than the eductor?
Eductor will not flow enough water to pick up foam concentrate
Explain how Foam puts out fire by penetration?
Lower the surface temp of water and allows it to penetrate fires in Class A materials
What is the concentration rate of foam used on polar solvent fires?
3 to 6 percent
What does hydrophobic mean?
Incapable of mixing with water
AFFF stored in temp controlled environments, in original container have a shelf life of _______
20 years
Why aren’t complementary agents not as effective as primary agents?
They are prone to Flashback
What are two devices used to test finished foam?
Refractometer and Conductivity meter
What are the two ways to fill ARFF trucks with foam?
Topside Fill and Side Connection
Common elements from the halogen series are?
Cholrine
Flourine
Bromine
Iodine
When are self educting master stream nozzle used?
When GPM requirements exceed 350 gpm
What are two limitations to Protein Foam that led it being replaced by AFFF as the primary extinguishing agent?
Corrosiveness and inability to heal
Water converts to steam at an expansion rate of :
1700:1
What are (4) disruptions that should affect a good foam blanket?
Wind
Thermal updraft
Flame
Hydrocarbon attack
What can dry chemicals do to a protein foam blanket?
Degrade it
Dry chemical handlines are required to have ____ feet of hose, and a range of ___ feet
100 / 25
How does multipurpose dry chemical agents work?
It leaves a sticky residue on burning materials, creating a seal between the material and oxygen
What does CAV stand for?
Combined Agent Vehicle
Aircraft longer than ___ feet, have a TCA that that is 100 feet + the fuselage’s width.
65
What is the concentration rate of foam used on hydrocarbon fires?
1 to 3 percent
Plastic pails of foam should not be stacked more than how high?
3 pails high
Class D fires are put out with MET-L-X extinguishers, G-1 Dry powder or what?
Copious amounts of water
What is the most serious problem ARFF personnel will face when using foam?
They must quickly apply large quantities of foam to form a blanket on the fire
What is the PCA?
2/3rds of the TCA
How much foam does a pail hold?
5 gal
Where are CAFSs most commonly found?
Structural and Wildland fire apparatus
What two things must occur for foam to be used?
It must be proportioned and aerated
Discharge rate of dry chemical through an extendable turret is?
12- 22lbs per sec
How much foam does an Intermediate bulk container (IBC tote) hold?
250 to 450 gals
Medium expansion foam has an air/solution ratio of what?
A range of 20:1 to 200:1
What is a CAFS?
Compressed Air Foam System
Why shouldn’t polar solvent foams be used in ARFF trucks?
the foam concentrate is too viscous
What are two basic designs for handheld and wheeled dry chemical extinguishers?
Stored-pressure and cartridge-operated
Dry chemical hand lines must have _____ times the system working pressure
3
Rate of application of foam depends on what (4) variables?
Type of foam
Whether or not the fuel is on fire
Type of fuel
Whether fuel is spilled or in a tank
Hydrocarbons fuels are petroleum based and ________
Hydrophobic
Synthetic foam are made from what kind of products?
Petroleum
Aircraft shorter than ___ feet, have a TCA that that is ___ feet + the fuselage’s width.
65 / 40
What is the simplest means of proportioning foam?
Batch mixing (dump in method)
Class B fuels have two categories:
Hydrocarbons and Polar Solvents
Two of the most common halongenated compounds used for extinguishment are?
Halon 1211 and Halon 1301
What are two types of foam injection systems?
Direct Injection and Balance pressure proportioners
Dry chemical turrets must have a no wind range of ____ feet
100
What is the TCA?
A region along the length of fuselage in which ARFF personnel can control a fire long enough to rescue victims
ARFF personnel can mix foam concentrate with water, _________ or ________
brackish water / saltwater
How many more times effective is Purple K than Sodium Bicarb based dry chemicals?
2 times
Modern automotive fuel blends include gasoline with ___ percent or more solvent additives
10
