Re: [a/s] Propane Vehicles (was: New member intro.)

[Bilmoran@xxxxxxx]

A lot of very good conversation on the propane/gasoline subject! I hope it 
makes for good sense. ALWAYS BE CAREFUL! They will both get you if you are 
not.
"inflammable"= same as "flammable" but not as widely used anymore.
The vehicle is not flammable, the fuel in the tank is.

Gasoline and Propane are both dangerous if not handled properly. Both 
gasoline and fuel gas is safe in a "closed" container. 

Gasoline tanks must have a vent to allow air in as the gasoline is drawn into 
the engine and must be able to relieve any excess pressure fast enough so as 
not to build up in case the tank and liquid becomes heated as could happen in 
an accident involving fire. If the pressure is not relieved, the excess 
pressure causes the tank to rupture (mechanical failure of the tank due to 
the internal pressure exceeding the strength of the tank) or "BLEVE" which is 
a Boiling Liquid, Expanding Vapor Explosion. 
In a fire which heats the fuel tank, as the gasoline heats, and turns to a 
vapor (boils if you wish) the vapor takes up more space than the liquid and 
vents to outside of the tank. As it leaves, it burns and is of no more 
danger. If it does not burn, it accumulates in low areas and awaits a source 
of ignition (flame, cigarette or spark), then it catches fire all at once 
(explosion). 
In the case of propane, butane or liquefied natural gas (the real bad stuff), 
it is in the closed tank, under pressure (DOT cylinder). What they have done 
is to pack a lot of gas into the tank, so much so that it has become a liquid 
because of the pressure involved. It is the liquid that is transferred when 
you get a fill-up. Anyhow, the liquid will turn to a gas when it is no longer 
under the pressure of the tank. If it gets hot enough, it will turn to a gas 
within the tank (sun hitting the tank). If the amount of liquid and gas 
combined exceeds the capacity of the tank, it is designed to vent relieving 
some of the pressure. If this cannot happen, you have a mechanical failure of 
the tank due to the internal pressure exceeding the strength of the tank. 
Either way, when this happens the propane and butane (liquefied petroleum) 
gas escapes and accumulates in low areas and awaits a source of ignition 
(flame, cigarette or spark), then it catches fire all at once (explosion). 
The liquefied natural gas will go up because it is lighter than air but will 
also explode if it finds an ignition source. Sometimes the source if ignition 
is right there and the gas burn as it leaves the tank. Fire fighters will 
allow the gas to continue to burn until the source can be shut off. That way 
it will not accumulate and explode.
FLASHPOINT= the lowest temperature at which a liquid will give off vapors 
capable of ignition (at atmospheric pressure). 
EVERYTHING has to be changed to a vapor in order to burn it (this includes 
diamonds that burn at around 1400 degrees F). 
If you take a cup of flammable liquid and cool it, at some point it will be 
too cold to give off vapors capable of being ignited. In the case of Diesel 
fuel, you can wave a match over the surface if it is under 100 degrees F. 
(give or take a little) Put it in the sun and allow it to heat up and you 
better not try it. (The flashpoint of diesel is right around 100 degrees F.)
With a gas, there is no flash point because it always gives off vapors 
because it is already a gas.
Yes, the codes are different because they are dealing with entirely different 
materials. The National Fire Protection Association which has a web site:  <A 
HREF="http://www.nfpa.org/">National Fire Protection Association Home Page</A>
 writes standards for all sorts of things. Their standards are adopted into 
law by governing agencies. NFPA 30 is the standard that regulates Flammable 
and Combustible Liquids and NFPA 58 deals with LP.
Fire people don't like LP in tunnels nor buildings because it is in a 
confined space. If it should escape or leak out of the tank it will look for 
a source of ignition. When it finds it, it will ignite all at once and 
increase in volume (deflagaration). If it is contained and cannot expand it 
will increase in pressure (explosion).
I know that was windy, but I hope it clears it up.  Bill