Date:         Wed, 05 Jun 1996 17:24:15 -0600
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         ldjones@concentric.net (Leonard Jones)
Subject:      Propane Filling

morris:

I have done this myself on occasion.  And- as a matter of fact, some propane
dealers use the gravity method to fill tanks.  Shouldn't be a problem as
long as you are very careful.  

1)  No open flames - campfires, cigars, cigarettes, etc. anywhere around the
area where you are doing the propane transfer.  Also - make sure that there
is good ventilation - no unvented areas where gas could build up and push
out oxygen - or where explosive propane/air mixtures could develop.

2)  No hot exhaust parts near the area where the transfer is going on.  

3)  Ignition switched OFF - no accessories or anything else on.  All pilot
lites out!

4)  Make sure that your camper's propane distribution system is disconnected
or positively valved off from the tank(s) so that there is absolutely no
chance liquid propane could enter the tubing of the distribution system.  If
this happened, you could easily have a serious fire or explosion.

5)  The piping or tubing between the donor tank and the receipient tank
should be as short and as direct as possible - leaving no room for "vapor
locks" between the two tanks..

6)  If it is even remotely possible that the receipient tank could be
completely filled by the donor tank, the "80% vent" on the side of the
receipient tank shutoff valve should be opened while filling.  (Hard to
describe exactly - there are many variations)  If  liquid propane starts
coming out the "80%" vent, the receipient tank valve should be shut -  the
"80% vent" should be allowed to bleed until only vapor is coming out - then
it should be shut.  (Propane tanks are only filled ~ 80% full so there is
some headspace in the tank to allow room for adjustments of
pressure/temperature/volume - evaporation/condensation when the ambient
temperature changes.  If you fill a propane tank completely full when it is
cold and the ambient temperature later increases, it is possible that the
vapor pressure could increase enough to rupture the tank!)

There are some special fittings available from propane dealers that can be
plumbed into your system so you can use a small lantern-sized flask of
propane as an emergency supply until you can get your main tank refilled.
Using one of these would be better than refilling your own bottles in the field.

Another option is to plumb in a tubing tee and valve somewhere into your
distribution system so that you can use an auxilliary tank, regulator, and
hose sitting along side your camper.  A normal choice would be the ~5 gal
home barbeque size propane tank.  If you set the regulator on the auxilliary
just a trifle higher than the main camper tank, the aux. tank will empty
first.  Then you can take it off to a supplier for re-fill without moving
the camper.  This works really well if you want to camp in one place for
longer than a few days.       

Let me know if you have any questions.

leonard jones
wannabus