running gas line for furnace

Now that everybody has given you the answers to code problems and other such stuff, there's one problem with using the natural gas with your foundry furnace. After the gas goes through the meter it comes out at about, IIRC, at 7psi or something like that. Not enough pressure and volume to run a foundry furnace.

Bernd

Reply to
Bernd
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Reply to
Tim Killian

Tim,

I know it will run a furnace since I have natural gas. What I meant is that I don't believe there is enough pressure and flow to properly run a "foundry furnace" since you'll need about 30psi to get a flame. That's my experience with propane for a 5 gallon style furnace and a Ron Reil burner. So I would think you would need approximately the same amount of pressure to run on natural gas. The foundry furnace I'm talking about is al Gingery style. Now the 1/2 psi and a good volume with a blower motor might work.

Bernd

Reply to
Bernd

If you connect it, it will work. But the pipe will be whistling at very high flow rates, and pressure drop becomes a bigger problem.

If you can get the local gas company to do it, they can deliver the gas from their regulator and gas meter at 5 or 10 PSI instead of 7" WC / ~1/2 PSI, and then you use a second pressure regulator near the appliance to knock it down to 7" WC. That allows you to flow a lot more gas for the pipe size and distance involved.

But this is usually used for commercial and industrial applications, getting a medium-pressure feed done at a residence - even if only for the line back to the garage workshop - may be a huge problem.

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Reply to
Bruce L. Bergman

Oh, that's what you meant... ;-) Yes, they use the gas delivery pressure to get forced air induction, the gas drags the air along and into the burner. You can do the same thing with an electric powered forced draft blower on the burner to get the air moving, then the low gas pressure will mix into the combustion air flow.

This is how they build new hot-air furnaces and commercial water heater & boiler burners for Low NoX, the forced air and gas runs in "inshot" burners and gives a nice intense flamefront.

You can also use a draft blower in suction on the flue side of a sealed combustion chamber, but they are more trouble - the blower wheel is running in the flue gases and corrosion is a big problem.

Note: If this is going to be running unattended for more than a few seconds, be sure to add a diaphragm pressure switch on the blower output, and some sort of 'flame out sensor' linked to the gas valve control circuit. So if the forced draft blower quits for any reason the gas is shut off automatically.

(A simple low-tech KISS way to shut off the gas is the old standby Penn-BASO B-60 valve and a millivolt thermopile pilot light [used in millions of floor and wall furnaces] with the diaphragm switch in series, or you can get fancy...) ;-)

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Reply to
Bruce L. Bergman

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