About Fire Extinguishers

by Chuck (westyman71 at yahoo.com)

Not only am I a long-time VW owner (29 years), I have been a career firefighter for the last 23 years. Here's some information on these.

Most fire extinguishers out there are the "dry chemical" type. They have a powder (usually monoammonium phosphate) that interferes with the chemical chain reaction to put out the fire. All extinguishers are rated by their ability to put out different types of fires.

"A" is ordinary combustibles (wood, paper)
"B" is flammable liquids (gasoline)
"C" is safe to use on energized electrical equipment
"D" is flammable metals (sodium, magnesium, etc.)

The typical 10 pound dry chemical extinguisher out there is rated 4A, 60B, C. This means that when used by Joe Citizen, it will put out 4 square feet of ordinary combustibles, 60 square feet of flammable liquids, and can be used on energized electrical equipment. It also means that when tested by Underwriters Laboratories (UL), Factory Mutual (FM) or other testing organizations, the expert is able to put out 4 times the coverage area it is rated for.

A couple of things: 1) Flowing, burning flammable liquids won't be put out. So kill the fuel pump (ignition) so the fuel flow stops. It can reflash without warning, so be alert. 2) The powder gets everywhere!!! If the powder gets into sensitive electronic stuff (computers), it is usually toast anyway.

Recommendations:

Buy a nice sized one with a metal body and head. The previously described 10 pound model works pretty well.
Firmly mount or secure the extinguisher, as these things are not too cool if you have an accident -- they make nice missiles.
They should be pressure tested every 6 years by a certified shop.
Every once in a while, take it and turn it upside down to "unsettle" the powder.
If the pressure has leaked off out of the green, get it serviced. As long as it is still sealed and the pressure is up, they stay good for a long, long time.
If you use it, get it recharged.
If getting a recharge, call around, as prices can vary a lot. Sometimes it is just cheaper to buy a new one.
Mount the extinguisher within reach if possible. You don't want to be climbing around the back of a Bus, looking for an extinguisher, when the Bus is on fire.

Hope this helps,
Chuck