Date:         Mon, 8 Jan 2007 14:30:16 -0800
Reply-To:     Pensioner <al_knoll@PACBELL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Pensioner <al_knoll@PACBELL.NET>
Subject:      Re: Fridge more sensitive to low pressure than cooktop?
In-Reply-To:  <200701082120.l08LKUDi011007@flpvm05.prodigy.net>
Content-Type: text/plain; charset="iso-8859-1"

Have you actually measured the pressure?  Can be done with 8' of clear
plastic tubing and some water.  The "11 inches of water" lpg pressure is
pretty much a standard and the regulator can be adjusted somewhat to attain
this pressure.

At your friendly local RV supply store they can help you assemble a fitting
that will allow you to hook clear plastic tubing of the proper diameter to
the manifold to the fridge feed off the manifold.  Then you can form the
tube into a "U" shape drooping down from the manifold to the ground and then
back up to near the bottom of the window. The side of the "U" not connected
to the tank should be as vertical as possible. Tape the tubing to the van in
such a way that it is visible from the level of the lpg tank to 15" or more
above the level of the tank manifold.

Turn off the gas at the valve and disconnect the fridge feed on the
manifold.  Put the adapter on the fridge feed and turn on the gas
momentarily to purge any spooge or other undesirables that may have taken up
residence in the manifold.  Slide the clear plastic tubing onto the adapter.

Now put sufficient water in the tube to fill the lower portion of the "U"
and about 5" or so up each side of the "U".  Noticing that the water level
in each side of the U is essentially the same, mark the tubing with some
tape at the water level on the open side of the U (not connected to the
tank).  Put another piece of tape 11 inches +/- 1/16" above this mark.  You
now have a 11 in-H20 calibrated tool to use in recalibrating or checking
your lpg system.  Costs under ten bucks usually.

With the tube securely in place and attached to the fridge feed, turn on the
gas.  The miniscus of the water near the tape marks should rise in the tube
to the 11" mark.  Now turn on the stove and light both burners.  The
miniscus should not move more than 1/4" or so.  If it drops more the
regulator is unable to deliver gas at 11 in-H20 in sufficient quantity to
run the stove and the regulator is suspect.

You can adjust the regulator to vary the height of the miniscus somewhat.
Try to get it to 11 inches and redo the test.

Compared to the full-on stove the fridge takes very little propane flow but
does require the 11 in-H20 pressure to work correctly.

Around my patch there are very tiny spiders that seem to prefer making webs
in lpg orifices.  Judicious use of compressed air and blowing out these
orifices can send the critters packing for a while.  A pipe cleaner  can
also be used to roust the buggers out.  The webs block the flow sufficently
to cause poor performance even though the regulator is calibrated spot on.

Ask your local propane experts about this phenomenon, or just google propane
spiders.

Pensioner