Date: Mon, 11 Jun 2001 05:32:29 -0400
Reply-To: Stephen Steele <steeles@HORIZONVIEW.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Stephen Steele <steeles@HORIZONVIEW.NET>
Subject: Re: Engine Fires: A Professional POV
Content-type: text/plain; charset="US-ASCII"
Phaedra asked:
> Please address the question of propane explosions
> in vehicle engine fires!
> I carry two 1-gallon tanks under the jumpseat in my
> van; they are not hooked up.
> Inn case of engine fire, would it be wise for me to quickly
> unload these propane tanks--propane is HIGHLY explosive!
Propane is explosive and presents some potential problems in our vans.
Any leaks or problems after the pressure regulator are of a less potentially
harmful nature. Leaks in the system before the regulator are SERIOUS.
First of all, if the tanks (all tanks fixed or portable) are properly
plumbed , they will have a pressure relief valve. On a properly mounted
tank, when heated, the valve will open and the LPG becomes a potential 'blow
torch'. That is the flow of gas can be lit by surrounding flames or sparks
and the resultant fire will burn intensely until it runs out of fuel. Short
of experienced help, the best scenario here would be to stay away. If you
HAVE TO do something, use a (water) hose line to cool the top of the tank to
prevent an explosion. My caveat about personal safety applies ten-fold here.
Portable tanks when improperly stored and heated can explode.
Secondly, in storing portable tanks, it is imperative that you secure them
so that they do not become loose and cause other problems.
A loose tank, if knocked about causing the neck to break, can become a
rocket propelled missile; OR, even if depressurized, the liquid fuel could
pour out and add to the fire load. If, in a non-fire scenario, a tank starts
to leak or the pressure relief valve opens, the best action would be to shut
off the van and leave the door open as you quickly exit to a safe distance.
Smaller tanks such as your 1 gal. (ten pound....?) will dissipate harmlessly
if no sparks are present.
Always mount the tank in the orientation of its use... if it is used upright
(as most are), mount it upright. This allows the tank to vent properly with
the fuel exiting the tank as a gas and not as a liquid. When mounted in the
wrong orientation and heat is applied, the liquid fuel inside can block the
gas from escaping and the gas expands until it goes BOOM. Portable tanks
when improperly stored and heated can explode.
To answer your question about removing the tanks in an emergency...it all
depends on the situation. In an engine fire, I personally would grab the
extinguisher, exit and go to the engine compartment. Quick action may avert
a total loss. AND if you are out of the van and the fire spreads forward,
the bulk of the van is between you and the tanks as you run away. In a
kitchen fire, it might be prudent to quickly remove the mounting strap and
get the tanks out of there. Remember...heat and flames rise. Aim your
extinguisher at the base of the flames/source of the fire...then look to the
secondary fires (things that were caught on fire by the initial flames).
Our mounted tanks are well sited for safety in their lower-than-the-floor
position. LPG is heavier than air and will flow downward if leaking. Even if
ignited the exterior sheet metal should shield enough of the flames to allow
for a timely exit.
> Has anyone *successfully* improvised holding brackets
> (perhaps of velcro straps) that improves on plastic straps
> provided with extinguishers?
> Something secure, but quickly released in emergency.
I use the thinnest slotted wire ties that will securely hold the bottles in
place. They are cheap, available at any hardware/FLAPS, and in an emergency
tear away quite nicely.
Again ...HTH.
--
Stephen
Chillicothe OH
