Marshall brass sells a product called "Extend-A-Stay tee which installs
between the regulator and tank. There are a few versions that allow the on
board tank to feed a BBQ or other appliance and also connect a separate tank
as a source when needed. It is the proper way to connect the tank. It does
not take up much space and the existing lines can be easily cut and
re-flared to make the connections.

Dennis

>From: Paul Chubbuck <paul@TAKINGFLIGHT.NET>
>Reply-To: Paul Chubbuck <paul@TAKINGFLIGHT.NET>
>To: vanagon@GERRY.VANAGON.COM
>Subject: Auxiliary propane tank
>Date: Wed, 25 Jul 2007 11:05:03 -0600
>
>About 6 weeks ago, someone on this list told me I could get a barbecue tank
>(propane) and a hose which would go from that tank to the inflow connection
>of the existing propane tank and thus have an additional "stay longer" fuel
>supply.
>
>When I went to a propane supplier today they said that won't work because
>there is a check valve which will only allow flow under the very high
>pressures provided by the fill systems.  They offered a solution which
>requires a valve and splitter be installed in between the shut-off valve
>and
>the OPD valve, but that is a big job requiring the plumbing be re-done
>because there is insufficient space and the copper plumbing is already
>pinched as it is.
>
>Does anyone have experience with this?  Are they correct in what they're
>telling me about that simpler solution not being workable?
>
>Thanks,
>Paul in Fort Collins