[AT] OT - AFFF Fire Foam Unit

[Richard Walker]

There used to be a few firefighters following ATIS, and I'm hoping 
for some help with an equipment question.

I recently bought a skid-mounted fire control unit ridiculously cheap 
at a municipal surplus auction.  It consists of a Halon portion and 
an AFFF (Aqueous Film Forming Foams) portion using CAF (Compressed 
Air Foam) technology.  I am only interested in the AFFF portion, 
since we live in a high fire danger area backed up to the San Gabriel 
Mountains in Southern CA.  If a wildfire heads our way, foaming down 
the house and surrounding vegetation beforehand can increase our 
chances of coming through OK.

The AFFF system is actuated from a large cylinder of high-pressure 
nitrogen.  A fixed regulator reduces this high pressure to a constant 
lower pressure.  I'm thinking about getting away from this dependency 
and converting to compressed air.  The air supply hoses leading to 
the pressurized foam solution tank are 200 PSI working pressure and 
1/2" in size.  So based on this, my wild guess is that the needed 
working pressure might be around 100 PSI and the air volume from 20 
to 50 CFM, assuming the hoses were roughly sized to the air requirements.

Would anyone with experience have a more precise answer as to 
pressure and air volume?

Whatever, that will take one BIG compressor.

Photo of the unit:

http://www.walkerpublications.com/tractors/FireFoam02.jpg

Thanks.


Richard