FOAM Flashcards
∙ There are two main categories of foam in use in the Department - low expansion foam and high expansion foam (Hi-Ex).
- Low expansion foams are extremely useful on fires and spills involving flammable and combustible liquids. They provide extinguishment and vapor control when properly selected and applied.
- High expansion foams are intended to fight fires of class “A” combustible materials in areas that are inaccessible to firefighters, such as cellars and ship holds. High expansion foam is not suitable for use on outdoor flammable liquids fires.
Advantages of Foam
∙ Foam extinguishes progressively. Firefighters can begin extinguishing a fire at
the edge of the fuel that is nearest them and continue to apply more agent,
projecting the boundary of the foam blanket further away with each movement.
. An important point to be considered is that the fire must be completely
extinguished or it will begin to burn back across the surface as soon as the
particular extinguishing agent begins to break down. All the concentrate that was
used will have been wasted.
∙ Foam can prevent ignition.
Foam Concentrate
∙ The Department presently uses the following Low Expansion Foams: Fluoroprotein, Alcohol Resistant Fluoroprotein (Fluoropolydol) and Aqueous Film Forming Foam (AFFF).= Can
∙ Different types of foam concentrates are not compatible and should never be mixed for storage, i.e. in the tanks of Foam Carriers, Tender etc.
∙ Hi-Ex foam is not to be used in conjunction with Low Expansion foam.
Synthetic= AFFF and Hi-Ex foam
Shelf life= 20 years
Protein Based= Fluoroprotein and Alcohol Resistant Fluoroprotein
(Shelf life= 10 years)
Foam Solution= the mixture that results when foam concentrate is proportioned at a
predetermined rate with water.
∙ When a “Foam Can” is going to be used, a precautionary foam line should be made ready.
∙ Educt the concentrate into a moving stream of water using a foam eductor.
∙ Foam solution can be produced by injecting a supply of concentrate at the proper
proportion into a pumper that is also receiving a source of water. The foam and water mix in the pump and are discharged as solution. This is accomplished by means of the Foam Injection Metering Module (FIMM) built into the Satellite pumpers. Satellite Units also carry a portable FIMM, which can be used if the built-in FIMM is out-of-service or the back-up Satellite Unit with a conventional pumper will operate.
Finished Firefighting Foam= is what is applied to the fire or spill and accomplishes the
extinguishment.
FOAM:
- Smothering
- Suppressing
- Separates
- Cools
There are times when we may be operating in or near a non-aerated foam blanket:
Example 1. An oil burner fire where the AFFF foam can with its straight stream nozzle
has been used to knock the fire down.
Example 2. A fire or emergency at one of the airports where the Port Authority crash trucks have applied AFFF to a spill. It is important to recognize the fast draining nature
of the AFFF foam under these circumstances and avoid entering the area until a stable
Fluoroprotein or Alcohol Resistant Fluoroprotein Foam blanket has been established
throughout the area to control the vapors.
Fluoroprotein Foam
- Slow Draining
- Sticks to metal
- Good blanket for rescue
- Good for gasoline
- NOT good for Polar Solvents or Alcohol
- Works with Dry-Chem
- Pour point 10◦ F
- Can use Salt Water
Alcohol Resistant Fluoroprotein Foam (Fluoropolydol)
- Good for Gosoline, Hydrocarbons, and Polar Solvents(Alcohol,Keytones)
- 3% for Hydrocarbons
- 6% for Polar Solvents
- Preferred for entering foam blanket
- Slow Drain
- Very corrosive to metals
- Store in plastic or Stainless steel containers
- Pour Point 5◦F
- Has excellent resistance to disruption by wind and water spray.
- Good sealing against hot metal surfaces such as tank sides.
Aqueous Film Forming Foam (AFFF)= AFFF is limited to the 2½ gallon pressurized water extinguisher, which uses a straight bore nozzle.
- Quick knockdown with less product
- Can be used through a standard fog nozzle
- Quick Drainage (BAD)
- Good for Fuel Oil, Kerosne, and Jet Fuel
- NOT good for Polar Solvents or Gasohol
- Doesn’t work well with wind and water spray
- Bad for sealing against hot metal surfaces such as tank sides.
Alcohol Resistant Aqueous Film Forming Foam (ARAFFF) or (ATC)= common in the oil
industry
- Good for Polar Solvents, Alcohol, and Gasoline
- Bad for sealing against hot metal surfaces such as tank sides.
- Pour Point 45◦F= Bad for cold weather ops
- Fluoroprotein= BROWN
- Alcohol= GREEN
- Hi-Expansion= YELLOW
- AFFF= BLACK
.
∙ Mixing of different concentrates must be avoided at all costs, particularly in storage tanks such as the booster tanks of Foam Carriers or the Foam Tender.
∙ Even two different brands of the same type concentrate mix, can have a very destructive effect on the foam.
∙ At times, the Department will intentionally apply two different types of Finished Firefighting Foam at an incident. This is routinely done at aircraft incidents. The Port Authority crash trucks are mandated by the Federal Aviation Administration to use AFFF, due to its fast knockdown capability on jet fuels.
After the evacuation has occurred, FDNY units will arrive and may be faced with the task of overhauling the scene. This could involve entering a foam blanket that is floating on jet fuel. Prior to and throughout the entry to this area, a blanket of aerated Fluoroprotein or Alcohol Resistant Fluoroprotein foam should be applied to provide maximum security to our members.
∙ Dry chemical must be used to extinguish a three dimensional fire when the burning fuel is dropping down.
This can be accomplished by discharging the dry chemical into the foam stream. The foam stream will carry the dry chemical to where it is needed.
