Author Topic: Propane connections  (Read 1722 times)

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Offline dmgood

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Propane connections
« on: September 03, 2013, 10:26:09 AM »
I purchased an old Comstock Castle P018 propane pizza oven.  I thought it would be no big deal to hook it up but after reading the company's installation manual I have doubts and fears of risking life and limb.

The oven has a 3/4 inch National Pipe Thread (NPT) connector and is rated for 10" Water Column (WC) which is roughly 1/2 psi.  The installation manual recommends using a 3/4" rigid pipe to provide enough gas for the burners. I had tried a 3/8" hose and was 'starving the flame'.  I found a flexible hose kit from Dormont for restaurant/commercial use that is 3/4".

I bought a low pressure regulator with an Acme nut to fit the tank with a 3/8" outlet. I bought a brass pipe fitting to go from 3/8" immediately up to the 3/4" hose. The low pressure regulator puts out 11" WC but with 4 feet of 3/4" hose, two elbows at the oven and possibly an elbow at the regulator I've probably lost some pressure (not sure if I've lost an inch WC). I will test all connections with a rich soapy water and check for bubbles.

The oven only needs 25,000 BTU and a 20 lb tank should be able to provide that. I have a 20 lb LP tank to start. I may go to 40 lb if can't get the pressure from the 20 lb tank. The oven will be on my enclosed patio. The tank will be outside.

Does anyone see any problems with this as a hookup? Is anything I'm proposing putting me at risk?

Offline Jet_deck

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Re: Propane connections
« Reply #1 on: September 03, 2013, 03:53:46 PM »
You said you were starving the flame.  How many shutoff valvles between the tank and the grill.  One on the tank, and one adjustable valve on the oven?  If so, you have got to make sure that the one on the oven is completely off, before opening the tank.  Otherwise the OPD will limit the amount of propane leaving the tank...
Her mind is Tiffany-twisted, she got the Mercedes bends

Offline barryvabeach

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Re: Propane connections
« Reply #2 on: September 03, 2013, 06:02:19 PM »
I am not sure I understood exactly what you are doing but wanted to make a few points.  I looked through the manual and saw they want you to keep it at least 6 inches away from any combustible surfaces, make sure you heed that warning - it is not designed to be used in homes, so you can't put it up against anything that will burn.  Second,  25,000 btu is not a lot for a propane system,  many outdoor grills go 75,000 btu or higher when you add in all the burners, and they commonly run off a 10 foot flex hose with a disconnect, so I don't think a few 3/4 inch elbows will cause that much of a problem.  I saw the description of how the supply must be run in the manual, but the manual seems to cover all their models, including the F3 series ovens - which I assume means the F3218 ( according to the catalog that is 242,000 btu ) . F330  ( 174,000 btu ) all the way up to F3226 ( 300,000 btu)  The product catalog says they use a 3/4 inch supply,  so probably to make things consistent, that is what they use for all their products, even the pizza oven that only uses 25,000 btu -  so if it were me, personally, I would not think that a few elbows are a problem.  The manual does tell you to measure the pressure at the appliance.  If you think it is starved, and you ruled out the issue Jet raises with the OPD on the propane tank,  I would call a small appliance repair company, or a gas certified installer to come check the pressure at the oven to see if it is okay and check the flame to make sure you are getting enough air and gas.