Foam Operations for Firefighters

TOPIC: FOAM OPERATIONS FOR FIREFIGHTERS TIME REQUIRED: THREE HOURS MATERIALS: FOAM NOZZLES, FOAM EDUCTORS, FOAM SOLUTION, HOSE AND APPARATUS (OPTIONAL) REFERENCES: ESSENTIALS OF FIRE FIGHTING, FOURTH EDITION, IFSTA PUMPING APPARATUS...


      d. Can be used with regular water stream equipment

      e. Can be premixed with water in booster tank

      f. Mildly corrosive

      g. Requires lower percentage of concentration (0.2 to 1.0) than other foams

      h. Outstanding insulating qualities

      i. Good penetrating capabilities

      j. Primary use in extinguishing Class A combustibles only

     k. Can be used with compressed-air foam systems (does not require aeration)

 

II. FOAM OPERATIONS (EO 1-2)

A. Application Rates

  1. Dependent on type of foam concentrate used, whether or not fuel is on fire, type of fuel

      (hydrocarbon/polar solvent) involved, and whether fuel is spilled or in a tank

  2. Hydrocarbon fuel spill fires (non-diked) – protein and fluoroprotein foams: 0.16 gpm/sq. ft. of

      surface area for 15 minutes; AFFF foams: 0.10 gpm/sq. ft. of surface area for 15 minutes

  3. Polar solvent fuel spill fires – range is between 0.10 and 0.20 gpm/sq. ft. or surface area,

     depending on manufacturer’s UL listing

  4. Hydrocarbon fuel fires in fixed roof storage tanks – 0.16 gpm/sq. ft. of surface area. Combustible

      liquids require a 50-minute application time; flammable liquids and crude petroleum require a

      65-minute application time

  5. The application rate for Class A foam is the same as the minimum critical flow for water

  6. Example of application rate for hydrocarbons:

      a. An area of 2,000 square feet of regular gasoline burning and 3%/6% AFFF foam is available

      b. Application rate per square foot times the number of square feet of surface area (0.10 gpm per

          sq. ft. X 2,000 sq. ft.) equal amount of foam solution (200 gpm) required

      c. Proportion percentage times application rate (3% X 200 gpm) equals amount of concentrate (6

          gallons of 3%) required per minute

      d. Concentrate requirements per minute times application period (6 gallons X 15 minutes) equals

          amount of concentrate (90 gallons of 3% AFFF) of required to control, extinguish, and initially

          secure the 2,000 sq. ft. hydrocarbon fire

      e. Application rate also tells what hardware is required for a given size fire

B. Water and Concentrate Requirements

  1. A 5-gallon container of 3% foam concentrate requires 161.7 gallons of water and will produce

     166.7 gallons of foam solution

  2. A 5-gallon container of 6% foam concentrate requires 75.2 gallons of water and will produce 80.2

      gallons of foam solution

  3. In the example above, the 90 gallons of 3% foam concentrate will require 2,917.6 gallons of water

      and will produce 3,000.6 gallons of foam solution

 

III. FOAM APPLICATION (EO 1-3)

A. Methods

  1. Roll-On

      a. Foam stream is directed on ground near front edge of burning liquid pool

      b. Foam then rolls across surface of fuel

      c. Application continues until it spreads across entire surface of fuel and fire is extinguished

      d. May be necessary to more stream to different positions along edge of liquid spill to cover entire

          pool

      e. Method only used on pool of liquid fuel (either ignited or unignited) on open ground

  2. Bank-Down

      a. Employed when elevated object (wall, tank shell, etc.) is near or within area of burning pool of

          liquid or unignited liquid spill

      b. Foam stream is directed off object, allowing foam to run down onto surface of fuel

      c. May be necessary to direct stream to various points around fuel area to achieve total coverage

         and extinguishment of fuel

      d. Method used primarily in dike fires and fires involving spills around damaged or overturned

         transport vehicles

  3. Rain-Down

      a. Used when roll-on and bank-down methods are not feasible because of either size of spill area

          or lack of an object from which to bank foam