What is Foam?

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FOAM APPLICATION
TECHNIQUES
HOSTED BY THE
Jefferson County Fire and
Rescue Training Academy
TACTICS
• DO NOT START A FOAM OPERATION IF
YOU DO NOT HAVE ENOUGH FOAM. (The
fire will not go out and you will just waist foam)
• *INSTEAD, ATTEMPT TO PROTECT
EXPOSURES OR EVACUATE
• IF YOU HAVE AN ETHANOL FIRE, USE ARFOAM
• IF AT A FIXED FACILITY, ASK THE PEOPLE
THAT WORK THERE FOR HELP. (They are
the experts with the product on fire.)
OBJECTIVES
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TERMS
HOW FOAM WORKS
FOAM GENERATION
TYPES OF FOAM
APPLICATION RATES
FOAM EQUIPMENT
PRACTICAL EVOLUTION
What is Foam?
• NFPA- 11 describes Foam as an aggregate of air
filled bubbles and is lower in density than
flammable liquids.
• Must be able to–
–
–
–
–
Flow Freely
Have a high resistance to heat
Fuel tolerance
Form a tough, cohesive blanket
Must hold water
Foam’s Extinguishing Characteristics
Smothering: prevents release
of vapors
Separating: creates a barrier
between the fuel and fire
Cooling: lowers temperature of
the fuel
Limitations of Foam
• Foam solution is 94%-97% water
– Cannot be used on:
• Electrical fires
• Three Dimensional Fires
• Pressurized Gases
• Combustible Metals
Kinds of Foam
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Protein
Fluroprotein
Film Forming Protein (FFFP)
Aqueous Film Forming Foam (AFFF)
Alcohol Resistant AFFF (ARFFF)
Aqueous Film Forming Foam (AFFF)
• Good penetrating characteristics
• Can be used with non-aerating nozzles
• Spreads a vapor-sealing film over fuels
• Can be pre-mixed
• Can be mixed with antifreeze
• Good low temperature viscosity
May be applied directly on fuel
surface, applied indirectly, or used
with subsurface injection
Foam Delivery Systems
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•
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In-Line Eductors
Around the Pump Eductor
Compressed Air Foam System
By-Pass Line Eductor
In-line Foam Eductors
Most commonly used
Attached to pump or at some
point in the hose lay
The foam concentrate inlet to the inductor
must be no more than six feet above the
surface of the liquid foam concentrate
Venturi Principle in Eductors
As water at a high pressure
passes over a reduced opening, it
creates a low pressure near the
outlet side of the eductor
The low pressure
creates a suction
which draws the
foam concentrate
into the water stream.
REMEMBER
• MATCH NOZZLE TO EDUCTOR
• MAINTAIN 200 PSI INLET
PRESSURE
HYDRAULICS
Back Pressure should not exceed
70% of inlet pressure
• Back Pressure=NP+FLH+FLE
250’ of 1.75” and 0’ elevation
– FLH= 100 + 30psi + 0= 130 psi
– FLE= 70 psi
• 130psi + 70 psi= 200 psi
Foam Production
• Foam must be proportioned with
water and aerated with air to be
used effectively
• Most fire fighting foams are
designed to be mixed at 3% to
6% concentrate in water
Foam & Foam Streams
To be effective, foam
concentrates must be
matched to the fuel to
which they are applied
DETERMINE TYPE OF LIQUID
• POLAR SOLVENTS- .16 GPM SQ. FT.
• HYDROCARBONS - .10 GPM SQ. FT.
HOW MUCH FOAM - NFPA 11
1. DETERMINE SQUARE FOOTAGE
10 FT. X 1OO FT.= 1000 SQ. FT.
2. DETERMINE TYPE OF LIQUID
POLAR SOLVENT- .16 GPM/SQ. FT.
HYDROCARBONS- .10 GPM/SQ.FT.
APPLICATION RATES
hydrocarbon fuels
3.
4.
DETERMINE AMOUNT OF FOAM
CONCENTRATE.
100 GPM X .O3 = 3 Gal. Foam/Min.
AMOUNT REQUIRED FOR 15 MIN.
3 GPM X 15 MIN. = 45. Gal of Foam will
be required.
APPLICATION RATES
hydrocarbon fuels
5. Determine amount of water needed
100 GPM X .97 = 97 GPM
97 X 15 = 1455 Gallons of Water
Foam Application Methods
• Roll – On Method
• Bank Down Technique
• Rain – Down Method
FOAM APPLICATION
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•
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SCBA
SWEEPING MOTION
DO NOT PLUNGE FOAM
DO NOT WALK IN LIQUID
DO NOT TURN YOUR BACK TO
FLAMMABLE
• DO PRESERVE THE FOAM BLANKET
Causes of Poor Foam Generation
• Eductor and Nozzle Mismatch
• Too Much Hose between Eductor &
Nozzle
• Nozzle Elevation
• Partially closed Nozzle Shut Off
• Kinked Discharge Line
• Fuel Mixture comprised of 85% ethanol and 15
% gasoline
• Fires should be treated differently than
traditional gasoline fires– These mixtures are polar/water-miscible flammable
liquids ( ie- they mix readily with water)
– Degrade effectiveness of fire-fighting foam which is
not alcohol- resistant
• Refer to Guide 127 ( Flammable Liquids
Polar/Water Miscible) of 2004 ERG
PRACTICAL
• HOOK-UP EDUCTOR
• MAKE SURE NOZZLE MATCHES
EDUCTOR
• SET METERING DEVICE
• SET FLOWING PRESSURE
• INSERT PICK-UP TUBE INTO FOAM
QUESTIONS?
DETERMINE AMOUNT OF
FOAM CONCENTRATE
600 GPM X .03 =
18 GAL. FOAM MIN.
Fluoroprotein Foam
 Good water-retention capabilities

Excellent heat resistance
 Not affected by freezing &
thawing

Can be mixed with antifreeze

Good fluidity on fuel surface
Protein
Foam
Excellent water-retention capabilities

 High heat resistance and re-ignition
resistance
 Performance can be affected by
freezing and thawing
 Can be mixed with antifreeze
 Can be made resistant to alcohol
Do not allow foam to plunge into
burning liquids.
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