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-   -   Gas line extension - black iron or copper?? (http://www.diychatroom.com/f7/gas-line-extension-black-iron-copper-26430/)

Joshua77 09-07-2008 04:07 PM

Gas line extension - black iron or copper??
 
I need to extend an existing black iron gas line to supply a new gas stove for my kitchen remodel. I'd like to avoid the extra labor of working with black iron and I enjoy working with copper so I'm wondering what disadvantages there may be, if any, to using rigid copper as gas line.

Fortunately, it will be convenient to replace a 90 elbow with a T at the point where I need to extend the existing gas line.

Any suggestions... preferences?

biggles 09-07-2008 04:53 PM

how about a flex line off the tee right into the stove

clasact 09-07-2008 09:19 PM

frist thing I would do is check to see what the code is for your area it may just answer your question for you.Some places only allow the black iron others will allow some copper depending on the use and distance.Where I am I must use iron to the kitchen for stoves and ovens but I can run copper or the expensive yellow gas line to the fireplace so check the code first

Termite 09-07-2008 09:30 PM

Rigid copper is not used for gas. Sweat and compression fittings are not legal or appropriate. Flexible copper tubing (flare fittings) can be used in some areas, but the gas composition can be problematic in many areas. Copper is uncommon for gas pipe these days.

For DIY, your best bet is to use black steel threaded pipe.

Flexible CSST gasline is another option, but is typically not a DIY process. Most of the time, it isn't available on a retail basis, so a plumber must install it. I've heard of it being available to DIYers in some cases, but I strongly recommend against installing CSST yourself.

Nestor_Kelebay 09-07-2008 11:27 PM

Does anyone know why local piping codes might not allow rigid copper to be used for gas piping? Is it just that they don't like the idea of anyone working on a gas line with a propane torch?

Termite 09-07-2008 11:39 PM

Quote:

Originally Posted by Nestor_Kelebay (Post 156069)
Does anyone know why local piping codes might not allow rigid copper to be used for gas piping? Is it just that they don't like the idea of anyone working on a gas line with a propane torch?

Nothing to do with the torch.

Two issues at play.

1) Gas contains hydrogen sulfide, which will eat copper up. Different suppliers have different levels. Copper isn't permitted in applications when the supplier delivers gas with more than .3 grains of hydrogen sulfide per 100 cubic feet of gas. Gotta check with the gas supplier and the codes authority.

2) Copper used for gas must be flared, threaded, or brazed. You can't do the first two to rigid copper. I believe that brazing is resistant to the chemicals in the gas whereas solder is not. Solder melts somewhere around 400 degrees. Brazing must be done in excess of 1000 degrees in order to be legal.

Maintenance 6 09-09-2008 02:04 PM

A fire in the structure would melt the solder on rigid copper lines, allowing gas in the line to contribute to the fire. Pressurized gas lines are not permitted to be soldered. Some are allowed to be brazed, like piped oxygen for example. I'm pretty sure that the plumbing code on this is derived from the NFPA standard on piped gases.

Termite 09-09-2008 08:57 PM

Ahhh, good thinkin!

Maintenance 6 09-10-2008 07:31 AM

Quote:

Originally Posted by thekctermite (Post 156670)
Ahhh, good thinkin!

Actually, I didn't think it. Some fire protection engineer with the NFPA did. :laughing: Kind of funny, I just got an e-mail update to proposed changes in the NFPA 99 piped gas standards this morning.

downunder 09-10-2008 06:39 PM

termite-
Quote:

Gas contains hydrogen sulfide, which will eat copper up.
What would be your guess on a time frame on this? My house is thirty years old, don't know of any problems there yet but this if the first time I have heard of this. Right now, the supply comes from the meter to one stick of black pipe, just enough to go from the meter and through the foundation and inside a little ways, then lines are T'd from the black pipe to everything. HW,stove, furnace.

Termite 09-10-2008 09:24 PM

Quote:

Originally Posted by downunder (Post 156991)
What would be your guess on a time frame on this?

Honestly, I go in 80-100 year old homes all the time that have flexible copper running gas, and it isn't degraded. Our gas supplier in this area is well below the acceptible limit for hydrogen sulfide, as are most major suppliers.

If you have flexible copper gaslines in your house it doesn't mean that you need to take the week off work and start replacing them immediately. They're probably just fine. Codes have changed in more recent years, making installation of copper gaslines a less desirable practice. If your lines are rigid copper and soldered connections, you need to remove them and install something that is appropriate.

downunder 09-12-2008 05:30 PM

Just for the info, all of my lines are flexible copper with flared unions. By flexible, I assume that we are not talking about the corrugated looking stuff that is usually made up in two or three ft lengths.

KEN19 09-21-2011 05:19 PM

I have a related question. I live in a rural are and there is now a problem with cooper thieves. Last week they cut the cooper tubing of my Propane gas tank and where it entered the house. Thank God they turn off the gas first. I want to know what other kind of lines can be used to replace the cooper ones.

ddawg16 09-21-2011 07:43 PM

Quote:

Originally Posted by Termite (Post 156074)
Nothing to do with the torch.

Two issues at play.

1) Gas contains hydrogen sulfide, which will eat copper up. Different suppliers have different levels. Copper isn't permitted in applications when the supplier delivers gas with more than .3 grains of hydrogen sulfide per 100 cubic feet of gas. Gotta check with the gas supplier and the codes authority.

2) Copper used for gas must be flared, threaded, or brazed. You can't do the first two to rigid copper. I believe that brazing is resistant to the chemicals in the gas whereas solder is not. Solder melts somewhere around 400 degrees. Brazing must be done in excess of 1000 degrees in order to be legal.

Natural gas varies a lot....especially BTU's....for the most part you can assume 1000 BTU's/ cu ft......but I've seen it vary quite a bit....I assume the Hyd sulfide could be the same as well...

Quote:

Originally Posted by downunder (Post 157561)
Just for the info, all of my lines are flexible copper with flared unions. By flexible, I assume that we are not talking about the corrugated looking stuff that is usually made up in two or three ft lengths.

Any chance they are coated on the inside? Most of the flexible stuff I have seen is coated.

oh'mike 09-21-2011 08:02 PM

Quote:

Originally Posted by KEN19 (Post 733189)
I have a related question. I live in a rural are and there is now a problem with cooper thieves. Last week they cut the cooper tubing of my Propane gas tank and where it entered the house. Thank God they turn off the gas first. I want to know what other kind of lines can be used to replace the cooper ones.

There is a yellow flexible line used for gas--It used to be that only licensed plumbers and heating guys could us it---things may have changed see what google has to say--

A knowledgeable plumber might see this and help,too.


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