Foam Equipment

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Foam Equipment Systems

• Sugar Land Fire Department
• Driver/Operator-Pumper Academy
• Spring 2003

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Know

• Foam Concentrate
• Foam proportioner
• Foam solution
• Foam
• Foam expansion

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Storing Foam

• Pails
• Barrels
• Apparatus Tanks

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Class A Foam
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Class A Foam

• Application ratessame as the minimum critical
  flow rate for water
• Application of foam types
• Wet foam areas requiring maximum penetration
  foam
• Dry foam vertical surfaces
• Medium foam areas requiring a balance of
  penetration and clinging ability

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Class B Foam

• Used for fires involving flammable and
  combustible liquids
• Proportioning
• Mixed from 1-6
• Follow the manufacturers instructions
• Factors that affect degree of expansion
• Type of foam concentrate used
• Accurate proportioning of the foam concentrate in
  the solution
• Quality of the foam concentrate
• Method of aspiration

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Class B Foam

• Foam expansion types/ratios
• Low expansion 20 parts finished foam for every
  part of foam solution
• Medium expansion 201 through 2001
• High expansion 2001 through 20001
• Application rates
• Type of foam concentrate used
• Whether or not the fuel is on fire
• Type of fuel involved
• Whether the fuel is spilled or in a tank

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• Regular protein foam
• Derived from naturally occurring sources of
  protein such as hoof, horn, or feather meal
• Rarely used in the fire service today
• Fluoroprotein foam
• Combination protein based and synthetic based
  foam
• Very high degree of heat resistance and water
  retention

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• Film forming fluoroprotein foam (FFFP)
• Based on fluoroprotein foam technology with
  aqueous film forming foam
• Aqueous film forming foam (AFFF)
• Completely synthetic
• Consists of fluorochemical and hydrocarbon
  surfactants combined with high boiling point
  solvents and water.

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• 3 by 63 on hydrocarbon fuels and 6 on polar
  solvent fuels
• 3 by 33 on hydrocarbon and 3 on polar solvent
  fuels
• 1 by 31 on hydrocarbon and 3 on polar solvent
  fuels

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Low-Energy Foam

• Pressure of the water stream flowing through an
  orifice creates a venturi action that inducts
  (drafts) 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.

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In-Line Foam Eductors

• Use the Venturi Principle to draft foam
  concentrate into the water stream
• Both nozzle and eductor must have the same rating
  in gpm
• Six rules
• The eductor must control the flow through the
  system
• Pressure at the outlet of the eductor must not
  exceed 65 to 70 percent of the eductor inlet
  pressure
• Foam solution concentrate is only correct at the
  rated inlet pressure, usually 150 to 200 psi
• Eductors must be properly maintained and flushed
  after each use
• Metering valves must be set to match the foam
  concentrate percentage and the burning fuel.

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Foam Nozzle Eductors

• Operate on the same principle as the in-line
  eductor
• Are built into the nozzle rather than the hoseline

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Self-Educting Master Stream Foam Nozzles

• Used where flows in excess of 350 gpm are
  required
• Use a rich, overproportioned solution that is
  diluted at the nozzle deflector plates
• Are available with flow capabilities up to 14,000
  gpm
• May use a jet ratio controller

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Variable-flow Variable-rate Injection Systems

• Operate off power supplied by the apparatus
  electrical system
• Control foam concentrate injection by monitoring
  water flow and controlling the speed of a
  positive displacement foam concentrate pump, thus
  injecting concentrate at the desired ratio.
• Can be used with all Class A foam concentrates
  and many Class B concentrates

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Variable Flow/Rate Direct Injection Systems

• Advantages
• Possess the ability to proportion at any flow
  rate or pressure within the design limits of the
  system
• Automatically adjust to changes in water flow
  when nozzles are either opened or closed
• May position nozzles either above or below the
  pump without affecting the foam proportioning
• May be used with high-energy foam systems

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Variable Flow/Rate Direct Injection Systems

• Disadvantage
• Foam injection point must be within the piping
  before any manifolds or distribution to multiply
  fire pump discharge

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Variable Flow, Demand-Type, Balanced Pressure
Proportioners

• The foam concentrate flow and pressure match
  system demand
• There is no re-circulation back to the foam
  concentrate tank.
• Water and/or foam solution can be discharged
  simultaneously from any combination of outlets up
  to rated capacity.

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High Energy Foam System

• (CAFS) Compressed Air Foam Systems
• Introduction of compressed air into the foam
  solution prior to discharge into the hoseline

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Advantages/Disadvantages

• Advantages
• The reach of the fire stream is considerably
  longer than streams from low-energy systems
• A CAFS produces uniformly sized, small air
  bubbles that are very durable.
• CAFS-produced foam adheres to the fuel surface
  and resists heat longer than low-energy foam
• Hoselines containing high-energy foam solution
  are lighter than hoselines containing low-energy
  foam solution or plain water.
• A CAFS provides a safer fire suppression action
  that allows effective attack on the fire from a
  greater distance.
• Most systems also designed to flow plain water.

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Advantages/Disadvantages

• Disadvantages
• A CAFS adds expense to a vehicle and adds to the
  maintenance functions that must be performed on
  the vehicle
• Hose reaction can be erratic with a CAFS if foam
  solution is not supplied to the hoseline in
  sufficient quantities
• The compressed air accentuates the hose reaction
  in the event the hose ruptures.
• Additional training is required for personnel who
  are expected to make a fire attack using a CAFS
  or who will operate CAFS equipment

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