Richard,

thanks for this. I was coming to same conclusion that "old europe"  
was using different gas mix after looking at info on propane gas  
industry of canada website:

"Propane Properties

A portable source of clean energy!

Propane is often called a liquefied petroleum gas (LP Gas or LPG).  
The term �liquefied gas� may be confusing but is this unique  
characteristic of LP Gas that makes it such a useful fuel. At normal  
temperature and pressure, propane is a gas. It changes to a liquid  
when cooled and moderately pressurized � about twice the pressure in  
a normal truck tire.

It is stored and transported in its compressed liquid form, but by  
opening a valve to release propane from a pressurized storage  
container, it is vaporized into a gas for use. Simply stated, propane  
is always a liquid until it is used. Even at -40C propane still  
vapourizes; that is why propane can even be used at extreme freezing  
temperatures.

LP Gas is liquefied to make storage and transportation easy and  
efficient. One unit of propane in a liquid form has the same energy  
content as 270 units of propane in a gaseous form. If left as a gas,  
the container to hold the fuel would be 270 times larger than what is  
required as a liquid.

Here are some other interesting facts:

Propane is a three-carbon alkane � its molecular formula is C3H8.
Propane is an odourless gas to which an odourant has been added to  
detect leaks.
Liquid propane boils (from liquid to vapour) at -44F (-42.2C).
At one and a half times the weight of air, propane will settle in low  
areas.
In a liquid form, propane is half the weight of water.
About 23.5 cubic feet of air is required to burn one cubic foot of  
propane. "

So I am good to go, up here in the  primitive cold north.

(disclaimer - I live in the warmest part of Canada)

alistair

On 8-Nov-10, at 6:52 PM, Richard A Jones wrote:

> One thing I worry about with
> propane heater tapped to westy tank, is freezing of external gas
> lines, just downstream of reg.

Two things:

European gas specs always talk about butane/propane and have
some temperature cutoff to deal with this.  We just have
propane here.

We have two stage regulators to deal with cold temps.  That's
what the 2nd stage is for--to prevent freezing, or regulate
in freezing temps.

The propane we have is fine to way too cold to camp.

I've camped in temps down to the low 20s and used my
heater--a Carver P4, now replaced with a Propex.

Disclaimer:  here, we, etc, refer to the US of A.  I can't
speak of primitive northern areas....

Richard