Date:         Wed, 26 Jul 2006 14:26:39 -0800
Reply-To:     Jack Cook <john.cook58@VERIZON.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Jack Cook <john.cook58@VERIZON.NET>
Subject:      Re: Propane fired airconditioning
In-Reply-To:  <44C75681.8020104@charter.net>
Content-type: text/plain; charset=US-ASCII

Seems, if my memory is correct, that propane fumes are heavier than
air and gasoline lighter.  If true this can make a difference in how each
either dissipates or mixes with air to create explosive mixtures.  The fact
that propane tends to pool or flow at ground level has always made me
nervous.

Hadn't seen this mentioned - seems important.  Or am I all wet?

//jack
'85 Vanagon

On 26 Jul 2006 at 6:48, John Rodgers wrote:

> I worked with an engineering firm who was employed by lawyers to provide
> the data to back up law suits over fires due to exploding hot water
> heaters. They build a cement block house with a hot water tank closet.
> The closet door had the usual 1-1/2 inch cut-off bottom for ventilation
> for the gas hot water heater. This construct is found inn many homes. A
> Camera was set up to record the room and a 3 pound coffee can with a
> small amount of gasoline  was placed in the middle of the room.
> Eventually, with evaporation. there would  be enough gasoline fumes in
> the room that it would begin to seep under the door to the hot water
> heater flame, and then BOOM! The fumes would ignitt, blowing the door
> off the closet and sometimes off the building. And of course there was
> the flash flame as well. All this was caught on tape and presented to
> the jury. Pretty conclusive in all cases, and the legal firm
> consistently won their case for the client.
>
> Fuel fumes, particularly gasoline fumes are not to be taken lightly.
>
> Regards,
>
> John Rodgers
> 88 GL Driver
>
> John Bange wrote:
> >> Propane has a much higher risk factor than gasoline due to it being a
> >> vapor
> >> at ambient temps and its extremely wide flammability range. That is why
> >> propane is restricted on almost all tunnels and some bridges.
> >
> >
> > FWIW, gasoline is generally identically restricted WRT tunnels and
> > bridges.
> > For example the Chesepeake Bay bridge-tunnel limits their transport to
> > 120gal for gasoline, 120lbs (141gal) for LPG. Not trying to downplay the
> > danger of propane; on the contrary I think people need to understand how
> > dangerous gasoline can be. Propane builds up to hazardous concentrations
> > faster, but consequently it also dissipates faster. Gasoline is
> > unlikely to
> > achieve an explosive mixture at normal temperatures, but consequently it
> > sits around as a fire hazard of comparable danger until cleaned up. When
> > either vents/spills onto a hot engine, BOTH will be in gaseous form-- and
> > gasoline the more volatile with an autoignition temperature of 536degF to
> > propane's 874degF.
> >
> > --
> > John Bange
> > '90 Vanagon - "Geldsauger"
> >
> >
>
>
> --
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