"Dave Fawthrop" wrote in message
...
On Sun, 03 Dec 2006 23:45:34 +0000, John Rumm
wrote:

|Aidan Karley wrote:
|
| the bottle valve (poor boy didn't know about left hand threads).
|
|That's a good point, why do gas cylinders / fittings etc use left
handed
|threads?

They *don't*, only *English* ones have left hand threads for
Flammable
gasses, which indicates the contents. Camping gas which originates
in
France has a right hand thread. I **HATE** the left hand threads
on my
Propane bottles, and after all these years I have to work it out
every time
I touch one :-(
--
Dave Fawthrop dave hyphenologist co uk Google Groups is IME the
*worst*

It's a perfectly sensible safety precaution to avoid connecting a fuel
gas to an oxygen or other non fuel gas regulator, which could have
literally explosive results. It is particulary vital with acetylene
which will detonate if too high a pressure is set when the gas is a
vapour rather than disolved in the kapok & acetone of it's cylinder.

The left hand threaded components are clearly marked with a groove
turned into the hex spanner flats.

AWEM