I need to buy ~25' of copper pipe to fix our badly kinked stove line. It looks similar to (but worse than) this pic:

enter image description here

I won't be able to measure the pipe for a couple days and the guy at Lowes wasn't able to help me determine what kind of pipe I need.

The pipe I'm using looks like the pipe in this image and is the only pipe I have seen connected to stoves before. I don't know the exact diameter, but it is approx the size of my pinkey (say, around 1/2"). The guy from the gas company who recommended replacing the pipe said that I could get the same thing, or a newer version with a yellow coating that would be slightly better (I read that as more durable).

I thought this was a pretty standard kind of thing though, no? Does anyone have a good guess of what I need to ask for at the hardware store?

  • You need to not only get the correct size, but the correct type for use with LP gas. You can read about copper tubing types in The Copper Development Association's Copper Tube Handbook. That said, I prefer the rigidity of black iron for gas, especially over that long a span. – Air Aug 27 '14 at 18:15

I'm not sure exactly where this pipe is, or how far back the pipe runs. Though most codes now call for a shutoff valve be installed for each appliance, in the same room and within 6' of the appliance. I'm going to assume that the piece of pipe you're looking to replace, runs from the shutoff valve to the appliance (this might be a terrible assumption, but you didn't supply much detail about your situation). If this is the case, you could use a piece of flexible copper pipe exactly the same size as the one you're replacing. Or you could use a corrugated stainless steel tubing (CSST).

As you've seen, flexible copper is prone to kinking, especially if you're moving the stove often. The CSST is more resilient to movement, and is typically easier for DIYers and homeowners to work with. If you do switch to CSST, you might find that you need an adapter to connect it to the valve. You should be able to find CSST fittings in various lengths, at your local hardware store.

If you choose to replace the pipe with flexible copper, you should shut off the gas and take the pipe with you to the store. With the pipe in hand, it should be no problem finding replacement pipe. You might also find that the end(s) of your copper pipe are flared. If they are, you'll also need to flare the ends of the new pipe. Some stores can do this for you. If they can't, you'll need a special tool to do it.

Without actually seeing the installation, it's difficult to provide any more specific information.

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    Also note that if you do replace the copper tubbing with copper tubing: while they sell compression fittings that will fit the copper tubing, typically compression fittings are not allowed on gas. You should confirm with your local code, but it will most likely require flared or solder connections. – pdd Aug 27 '14 at 23:36

It's very common to use either hard-drawn or soft-drawn copper for gas, whether natural gas or propane. Using it for long runs is not generally the greatest of ideas, but I don't think there are any laws against it - the issue with soft-drawn for long runs is the risk that some idjit will hang something really heavy from it & kink it or outright break it. Black iron pipe is a bit sturdier.

What you'll need to ask for is either simply "soft-drawn copper" or "refrigeration tubing" (who'd have thought that one?). It'll come in rolls of 10', 25', and 50' length. Be prepared for a little sticker shock; it's not terribly cheap. Much better, since you have to flare two ends anyway, to cut the pipe on both sides of that kink and install a coupling (or a pair of couplings with a short stub of new pipe between them) there instead and keep 98% of the original copper.

While you're at the hardware store, pick up a tubing bender - the type built like a longish (about 12" long) spring. You slip it over the tubing, and it helps prevent kinks like those as you bend the tubing inside the "spring". Please remember to take it back off the tubing before you flare the end... (BTDT). Also please please remember to put a flare nut onto the tubing before you flare the end.

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  • Refrigerator tubing, heh worked with that down on the dairy for hooking up the milk holding tank. The reefer unit was kind of undersized, so we'd be running a mist system on the condenser coils on a hot day like today. 103° F. – Fiasco Labs Aug 28 '14 at 4:15

In the end I had to buy 50' of 1/2" (interior diameter) copper tubing. I appreciate the suggestion from @TDHofstetter about reusing existing tubing, however I was not able to find this diameter tubing in lengths less than 50' : (

The diameter was a sticky point because it is measured from both the interior & exterior. We needed 1/2" interior. I cannot say if this is 'standard' for gas ranges or not, but (anecdotally) it looks right to me. One useful comment I got at Home Depot is that it is better to err on the larger side since smaller tubing can 'starve' (eg damage) an appliance.

Here are some references that may clear up the opinions stated in other answers:

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  • When talking pipe and tube the simple thing to remember is PIPE is measured INSIDE dia. and TUBE is measured OUTSIDE dia. – user60332 Sep 20 '16 at 21:03

Type K has thickest wall. Example Only; 1/2 inch nominal size has a 5/8 outside diameter and a little over a half inch inside diameter 0.527-in. Type K wall is .049, Type L wall is .040 and Type M wall is .028. Thinner wall is of course easier to bend, but may not be as puncture resistant as thicker wall tubing. Copper tubing should only be used for propane (LPG) gas, and NOT natural gas. FLARE or solder fittings only, NO compression (ferrule) fittings. Local codes take precedence.

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  • Hello, and welcome to Home Improvement. Thanks for the answer; keep 'em coming. And, you should probably take our tour so you'll know how best to contribute here. – Daniel Griscom Oct 16 '19 at 1:17
  • Note that there are codes and localities that permit the use of copper tubing for natural gas service (NFGC/IFGC logic conditions it on the gas having a low enough H2S content to not be deleterious to the copper) – ThreePhaseEel Oct 16 '19 at 2:38

I had a hot water tank and a gas grill piped with copper tubing, and I was told it was against code to use copper pipe for gas. It had to be removed and replaced. From what I understand, there is a special metal gas pipe (it's black coated and sold at Lowe's in the plumbing dept). I live in Kansas, and perhaps the copper is illegal only in Kansas, but it must have been determined to be unsafe over long-term use. If in doubt, call your county building inspection office and ask about the safety of copper tubing with gas.

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  • I would be very surprised if copper was not approved for gas. There are issues with the type of fittings used when using copper for gas installations, such as compression fittings are typically not allowed (must use solder or flared). – pdd Aug 27 '14 at 23:30
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    Except for with internal appliance connections, copper pipe and tubing for gas service is not normally "refrigeration tubing", at least not in my neck of the woods; it is type-L (or Type-M, thinner wall) hard copper pipe or coiled "soft copper", same as used for water. It is sized by O.D. but named by nominal I.D., in other words you would hypothetically ask for 1/2" Type-L copper, which is 5/8" O.D., whereas refrigeration tubing is named by O.D.; 1/2" is 1/2" O.D., compression fittings not allowed for supply lines but OK to use for internal appliance connections. – Jimmy Fix-it Aug 28 '14 at 3:43
  • On second thought, as suggested by TDHoffstetter, it may be flared 1/2" refrigeration tubing from the shut-off cock to the appliance. it was probably too long of a run for a manufactured flex line and they didn't want the trouble of extending the hard supply line. – Jimmy Fix-it Aug 28 '14 at 3:51
  • As per International Fuel Gas Code "Copper and brass pipe shall not be used if the gas contains more than an average of 0.3 grains of hydrogen sulfide per 100 standard cubic feet of gas (0.7 milligrams per 100 liters).". Not sure how common that would be. – Tester101 Aug 28 '14 at 10:11

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