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 AR-FOAM

• IF AT A FIXED FACILITY, ASK THE PEOPLE THAT WORK THERE FOR HELP. (They are the experts with the product on fire.)

OBJECTIVES

• 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

Smothering: prevents release of vapors

Foam’s Extinguishing Characteristics

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

• 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

• In-Line Eductors

• Around the Pump Eductor

• Compressed Air Foam System

• By-Pass Line Eductor

Most commonly used

Attached to pump or at some point in the hose lay

In-line Foam Eductors

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+FLE250’ 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 StreamsFoam & 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 LIQUIDPOLAR SOLVENT- .16 GPM/SQ. FT.

HYDROCARBONS- .10 GPM/SQ.FT.

APPLICATION RATEShydrocarbon fuels

3. DETERMINE AMOUNT OF FOAM CONCENTRATE.

100 GPM X .O3 = 3 Gal. Foam/Min.

4. AMOUNT REQUIRED FOR 15 MIN.

3 GPM X 15 MIN. = 45. Gal of Foam will be required.

APPLICATION RATEShydrocarbon fuels

5. Determine amount of water needed100 GPM X .97 = 97 GPM

97 X 15 = 1455 Gallons of Water

• Roll – On Method

• Bank Down Technique

• Rain – Down Method

Foam Application Methods

FOAM APPLICATION

• 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

PRACTICALPRACTICAL

• 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 FoamFluoroprotein Foam

Good water-retention capabilities

Excellent heat resistance

Not affected by freezing & thawing

Can be mixed with antifreeze

Good fluidity on fuel surface

Good water-retention capabilities

Excellent heat resistance

Not affected by freezing & thawing

Can be mixed with antifreeze

Good fluidity on fuel surface

Excellent water-retention capabilitiesHigh heat resistance and re-ignition resistancePerformance can be affected by freezing

and thawingCan be mixed with antifreeze Can be made resistant to alcohol

Excellent water-retention capabilitiesHigh heat resistance and re-ignition resistancePerformance can be affected by freezing

and thawingCan be mixed with antifreeze Can be made resistant to alcohol

Protein FoamProtein Foam

Do not allow foam to plunge into burning liquids.

Do not allow foam to plunge into burning liquids.