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...


      b. Primary manual application technique used on above ground storage tank fires

      c. Method directs stream into air above fire or spill and allows foam to float gently down onto

          surface of fuel

      d. On small fires, sweep stream back and forth over entire surface of fuel until fuel is completely

          covered and fire is extinguished

      e. On large fires, it may be more effective to direct stream at one location to allow foam to take

         effect there and then work its way out from that point

B. Proportioning

  1. In-line eductors work on venturi principle with water at high pressure (approximately 200 psi)

      being forced into a reducing oriface where it mixes with foam concentrate

  2. Six percent concentrates are mixed with water at a ratio of 94 parts water to 6 parts concentrate

  3. Three percent concentrates are mixed with water at a ratio of 97 parts water to 3 parts concentrate

  4. Once mixed with water, the resulting foam solutions of a 3% foam or a 6% foam are virtually the

       same with regard to performance characteristics

  5. By switching from a 6% foam to a 3% foam, you can either double your firefighting capacity by

      carrying the same number of gallons of concentrate, or cut your foam supply in half without

      compromising suppression capacity

  6. As a emergency measure, 15 gallons of foam concentrate poured into a 500-gallon booster tank

      will produce an adequate 3% foam solution with the pump serving as the eductor

C. Shortfalls

  1. Foam concentrates require large quantities of water to produce foam solution

  2. The nozzles and eductors must be matched in terms of flow rates

  3. Partially closed nozzle controls can result in a higher nozzle pressure

  4. Too long a hose layout on the discharge side of the eductor can result in poor quality foam

  5. Kinks in hose can result in back pressure and affect ability to produce foam solution or reduce the

      foam quality

  6. Nozzle too far above eductor can affect foam discharge

  7. Different types of foam concentrates should not be mixed because the mixture may be too viscious

  8. A regular combination nozzle can be used to discharge foam solution; however, since it has no way

     for air to be introduced, the expansion rate will be low. Aeration can be greatly enhanced by the

     addition of a clip-on foam tube to the nozzle

  9. You need to have an adequate supply of foam concentrate and water in place to meet the

      application rate requirements along with the equipment to apply the foam at the required rate

      before starting the foam operation. If you begin your operation without all the required supplies and

      equipment in place and the fire is not extinguished, you may have to start over at the beginning.

 

REVIEW:

FOAM OPERATIONS FOR FIREFIGHTERS

   • Foam and Foam Equipment

   • Foam Operations

   • Foam Application

REMOTIVATION: Foam and foam-making equipment are among those items of firefighting equipment that are carried on most engines but seldom used. When the need arises where foam must be used, it must be applied quickly and efficiently. Regular practice with the foam and foam-making equipment is important to maintaining knowledge and skills. The emergency scene is not the time to become reintroduced to the foam and foam equipment.