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
___ systems Are extremely versatile and accurate means to deliver foam.
Balanced pressure
___ systems are the most common foam type of system used today
Injection
CFAS hoselines are filled with approx __% compressed air
30%
Slug flow- If this charge in an erratic manner
__ mixing Process of pouring Foam concentrate directly into the fire apparatus water tank there by mixing a large amount of foam at one time
Batch mixing
___ nozzles Are the nozzle of choice when using CAFS
Smooth bore
Protein concentrate has a shelf life of __
Synthetic concentrates and high expansion of concentrates have a shelflife of __
7 to 10 years
20 to 25 years
Device mixes the foam concentrate into the foam stream in the proper percentage
Foam proportioner
