> The LPG cylinder has laws covering it's use, inspection, certification,
> maintenance and filling. For some info, see this website;
>
> http://www.coxontool.com/index.php/Airstream/Propane

There is a lot of very good info on that web site--but there is
(at least) one failure or omission.  There are two kinds of
propane tanks--DOT and ASME.  Vertical are DOT.  When it states
> the vertical (upright) standard cylinder and the horizontal
>cylinder that comes with a special mounting bracket and which
>can be installed either vertically or horizontally. Both cylinders
>are manufactured in accordance with U.S. Department of
>Transportation (DOT) specifications.
I start to wonder.  As I understand things, vertical=DOT and
horizontal=ASME.

Another good site is
http://home.comcast.net/~damouth/Tips/OPD.htm
When you read it, remember that all Vanagon tanks, unless
replaced, are newer than 1 October 1998--see the section
"Recent Exclusion of horizontal...."

Meanwhile, back to that Airstream site.  Lots of good information,
including about the regulator (2-stage), properties of LP gas,
etc, etc.  Some of those are on a web page I put up a year ago:
http://jones.colorado.edu/jones/PropaneFacts.html

With the propane tank, better safe than sorry.  If you have a
situation where you don't know or are worrying, then go to an
RV repair place--they will know, and they don't worry....

Richard
Boulder