PDA

View Full Version : OT Continuing saga of the propane furnace.



Your Old Dog
10-18-2007, 05:39 AM
I made a new brass orifice sized down for the propane burner from number 40 to number 49. But in removing the back plate to get to the orifice the asbestos type of gasket just fell apart. It feels like cardboard but no part of it is blackened by flame it really looks like asbestos.

Any ideas what I can use for substitute? There are no manufacture names on the unit so going to a dealer is out of the question. This gasket will sit along side (not above) the flame by about 1 1/2 inches away. The material they used looked to be about 1/16" thick and a rectangular picture frame design about 3/4" wide around the plate.

I haven't had much luck with the heating companies as I'm hearing about the insurance liability crap. All I wanted was a new orifice and couldn't find anyone to sell me one, said I had to be a heating contractor?

rwf71
10-18-2007, 06:28 AM
I think I would go to your nearest auto parts store & get a sheet of gasket material for exhaust (header) gaskets. I don't think it's asbestos anymore but takes high heat very well. Seeing how it's going to be 1.5" away from the side of the flame I'm betting it would work fine. Just my .02 , good luck, Rick

Sparky_NY
10-18-2007, 07:25 AM
I'm in the heating and a/c business. Most of the newer furnaces now use the red high temp silicone for sealing various things. Auto exhaust gasket material was a excellent suggestion also.

You mentioned changing jet sizes.... if your switching from natural gas to propane, or the other way, the gas valve also needs to have a conversion kit installed. The pressure regulator in the gas valve won't adjust enough to set it properly without it. Propane runs at roughly double the pressure of natural gas.

Your Old Dog
10-18-2007, 07:46 AM
"It was the best of time, it was the worst of times" !

Thanks for the automotive gasket idea rfw71!

Sparky_NY, if I ever see you again it will be too soon !! LOL. I already have a regulator as used on a 30K propane grill at the tank, are you saying the device at the furnace also needs reworked? I hope not as I can't secure the kits because I'm not a heating contractor. ??

Swarf&Sparks
10-18-2007, 10:52 AM
klingerite

Evan
10-18-2007, 11:23 AM
Use Permatex Copper Silicone Gasket. It's rated higher than the red at 750 degrees F.

As for the regulator buy an outboard regulator designed to regulate 2 psi natural gas to 12" water column. They aren't expensive and install at the inlet to the appliance. I have 2psi natural gas piped with propane style tubing and regulators at each appliance. The regulators have enough range to handle the propane pressure. If the regular suppliers won't sell to you try an RV dealer.

alsinaj
10-18-2007, 01:49 PM
You can get a regulator to step down to 11" of water (6-oz) rated 200,000 BTU/hr from Ace Hardware PN 4206066.

Your Old Dog
10-18-2007, 04:13 PM
Thanks for the help guys.

I have something that looks like this:

http://www.acehardware.com/product/index.jsp?productId=1437936&cp&kw=4206066&origkw=4206066&sr=1

I have one on the end of the line going to the 100 pound tank. This one came from a 30btu grill and a 20lb tank. Are we saying I just have to add another one to the other end of the line at the appliance to do the job like the one in the url above or is one enough? Thanks again.

Evan
10-18-2007, 04:38 PM
This is what I have. It has to be installed close to the appliance since once the pressure is reduced to 12" it isn't high enough to push through a small copper line very far.

http://vts.bc.ca/pics3/regulator.jpg

Your Old Dog
10-18-2007, 05:06 PM
Okay thanks Evan for going thru all the trouble of the pic. This stove was originally Natural Gas and I'm converting it to Propane use. So I'll have the conventional regulator at the tank and one like you picture at the appliance (furnace). Thanks for your help.

dhammer
10-19-2007, 03:10 AM
Hi,

I can't tell from Evan's picture if the regulator shown is an appliance regulator or "maxi trol" A maxi trol regulator is designed to be installed inside the dwelling and I believe in a horizontal position. A propane regulator for a barbeque grill is a single stage regulator designed to regulate tank pressure.. which on a hot day could exceed 100psi.. down to 11" of water column. In addition this type of regulator, if it should fail ,could expel gas through its vent.. not something you would want to happen.

You should be using a 2 stage regulator for LP gas use. You can buy 2 stage regulators that come as one unit or you can buy a hi pressure regulator that is intalled on the LP tank and a low pressure regulator that is installed on the OUTSIDE of your dwelling. It all depends on your line sizing, distance from tank to house and BTU requirements. Regulators designed for the outside of structures can be installed inside if the vent is piped to the outside.

Your Old Dog
10-19-2007, 06:16 AM
Hi,

I can't tell from Evan's picture if the regulator shown is an appliance regulator or "maxi trol" A maxi trol regulator is designed to be installed inside the dwelling and I believe in a horizontal position. A propane regulator for a barbeque grill is a single stage regulator designed to regulate tank pressure.. which on a hot day could exceed 100psi.. down to 11" of water column. In addition this type of regulator, if it should fail ,could expel gas through its vent.. not something you would want to happen.

You should be using a 2 stage regulator for LP gas use. You can buy 2 stage regulators that come as one unit or you can buy a hi pressure regulator that is intalled on the LP tank and a low pressure regulator that is installed on the OUTSIDE of your dwelling. It all depends on your line sizing, distance from tank to house and BTU requirements. Regulators designed for the outside of structures can be installed inside if the vent is piped to the outside.

Thanks a lot, couldn't make it any plainer than that. I'm a little dense these days so it helps!!

I'll do the high pressure regulator at the tank and low pressure at the appliance paying attention to the vent detail. Big thunder storms today so I'll get some shopping done on the project. Right now the line is
only about 12 feet but it will go to 45 feet of 3/8's copper tubing if the furnace proves to heat the shop.

dhammer
10-19-2007, 07:39 AM
Thanks a lot, couldn't make it any plainer than that. I'm a little dense these days so it helps!!

I'll do the high pressure regulator at the tank and low pressure at the appliance paying attention to the vent detail. Big thunder storms today so I'll get some shopping done on the project. Right now the line is
only about 12 feet but it will go to 45 feet of 3/8's copper tubing if the furnace proves to heat the shop.

I am sorry I confused you BUT you should have a hi pressure regulator at the tank and a low pressure regulator mounted on an outside wall.Then run your copper line to your appliance. You don't need a regulator just before the appliance. Some appliances have a built in regulator for safety. There could be a sitation where you would substitute the low pres regulator mounted on your house with a 2lb regulator.. if you needed a lot gas for hi BTU requirments or if you were piping a long distance with small line. In this case you would need an appliance reg just before or close to appliance. the idea is not to run gas at higher pressures through a dwelling.

FYI.. hi pressure regulators, usually red in color, reduce tank pressure down to 10psi. Low pres regs reduce 10psi to about 11". Two pound regulators take incoming 10 # psi and reduce it to 2#(just forget about the 2# regs)It will say on the regulator what the input/output is and in what direction the gas is supposed to flow.

Evan
10-19-2007, 08:50 AM
My setup isn't propane, it's natural gas and is installed according to code. We may use high pressure natural gas at 2 psi with copper tubing from the meter regulator to the appliances where a regulator must be installed just before the appliance.


the idea is not to run gas at higher pressures through a dwelling.
You don't mean 2 psi I hope.