14. Foam Flashcards
NIST Has determined that foam is __ times more effective than plain water in extinguishing fires
3-5x
Foam comes in two basic types
chemical and mechanical forms
Notes
Foam must have good knock down speed and flow as well as good fuel resistance
Class a and class B are not compatible
Surface tension
Low expansion 20:1
Medium 20:1-200:1
High 200:1-1000:1
Ability to shed hydrocarbons, quality reduces the amount of fuel saturation in the foam and prevents the phone blanket from burning
Oleophobic
Class A foams can extinguish class A fires ___ times faster than water
20 x
A __ agent reduces the surface tension of water and enhances penetration into the fuel that is burning
Wetting
Protein Foams should not be used with non-aspirating structural ___ nozzles
Fog
__ foam has Slower knockdown provides a longer lasting foam blanket after the fires extinguish
Protein foam
__ fuel Requires a low energy source to produce high-quality foam. Is very fluid and quickly flows around obstacles across the fuel service
AFFF
Is one of the most versatile types of foam, it provides good knock down and burn back resistance and has high fuel tolerance on polar solvents and hydrocarbon fuels
AR-AFFF
Class A concentrate
Class B concentrate
.1-1%
1-6%
Two types of proportioners
Educators and injectors
Class A foam concentrate that are batch mix must be used within
24 hrs
Two types of eductors are used in the fire service today
In-line and bypass
Most eductors are calibrated to flow the rated capacity at ___ psi inlet pressure
200 psi
No more than 150 feet for the nozzle and no more than 6 feet above the surface of the foam
