Date: Sat, 25 Aug 2007 13:28:07 -0700
Reply-To: neil N <musomuso@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: neil N <musomuso@GMAIL.COM>
Subject: Re: Dometic high altitude lighting tips
In-Reply-To: <vanagon%2007082511254964@GERRY.VANAGON.COM>
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Thanks Roger.
That makes sense. I may try adjusting reg when I get home.
Neil.
On 8/25/07, Roger Sisler <rogersisler2000@yahoo.com> wrote:
>
> I think at high altitudes the LP comes through the low altitude orifice
> jet at a higher velocity than is useable. Higher than at low altitude.
> Less air pressure up there to hold it back. What may be happening, is like
> in that John Wayne movie " Hell fighters". The flame gets blown right off
> the LP stream, and the fire goes out. In Hellfighters, they actually used
> explosives to blow the flame off the gas well head. That put it out. I
> think that this method of extinguishing well fires is actually used in
> Texas,too.
>
> In the Dometic, maybe the LP is coming out so fast that the flame head
> gets blown right off. A smaller jet may reduce this back to normal LP
> velocity. OEm jet is a number 22 and high altitude is #24. #24 is smaller.
>
> I think this lower high altitude velicity can be duplicated by reducing
> the regulator pressure from 11 inches. Dont know how much changing is
> needed though. Maybe 10 inches will keep the flame agoing. Actual window
> of useable LP pressure is about 11.5 , down to 9 inches, and still get the
> same end results.The stove should still work ok with this lower
> pressure.LP supply will last longer.
>
> People with Vanagon Westfalia with a regulator that seems to work ok at
> high altitude, may have never had it adjusted during its entire lifetime.
> Driving over rough roads for 20 years may cause the adjusting disk to back
> off, and actually lower the LP pressure.This would make operation at high
> altitude ok and still cool at sea level. My theory. The regulator in my 85
> was a half inch of WC too low, when first tested.
>
> There is no lock nut like device to keep the adjusting disk at the
> setting, measured. The adjusting disk is only a plastic disk about 1/8
> inch thick and the diametrer of a quarter. It has a opening for a hex
> screw driver bit in the center ( like a donut hole- Mmmm donuts) for
> adjustment.The disk is threaded on the outside rim, and screws into the
> hole. Fine threads. It pushes against a spring, which inturns pushes on a
> bellows.This bellows is contained in the wide circular area on the
> regulator. There is always simple mechanical pressure on the disk
> to "loosen up, or unscrew.This will reduce the pressure of the LP gas.It
> only takes about a 1/2 turn to change the LP pressure an inch of water
> column. Perhaps driving over bumpy roads for 20 years may be enough to do
> this loosening. Especially roads at high altitiudes, as the roads in
> Colorado which I have seen( at high alitutde) are gravel and dirt, and
> Westys like to go camping frequently. I think this is what is happening
> with westy owners that say their Dometics cool ok with the low altitude
> jet. If they adjusted their regulators to 11 inches of WC, the Dometic
> would poop out and get replaced with a NORCOLD.
>
> www.rverscorner.com for instructions for use and building a $2 manometer
> for checking your regulator. It is as easy to do as is the $2 for buying
> the materials.
>
--
Neil Nicholson. 1981 Air Cooled Westfalia -
"Jaco" (Bustorius)
http://web.mac.com/tubaneil
Please send me your Vanagon/Westfalia links!
http://vanagonlinks.googlepages.com/home
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