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Confusing Copper pipe outside diameter

branimal

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I have to relocate some domestic water copper pipe get access to another pipe. I put a couple turns on the pipe with my pipe cutter and looked over and noticed the pipe itself has threads on it. I've never seen copper pipe with threads. It's not a sweat on male adapter.

I took out my calipers and found the pipe's OD is .839ish. Copper pipe (Types M,L, or K) is 0.875 OD.

I've been in this situation a while back before with brass pipe (domestic water). I needed to buy a dressing coupling from brass to copper. See pic. Turns out the brass pipe in that situation was also .840 OD. (I recently took that apart so I had it on hand to measure).

But I'm looking at the copper pipe I need to move and it's definitely not brass. Looks like copper to me.

I'm going to clean up the pipe in question with sandpaper to get a better look.

Can anyone offer some pointers? Also anyone know if that dressing coupling is re-usable?
 

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branimal

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Did some more googling.... I think the pipe in question is brass. See OD chart below. The "dressing coupling" I referred to in my original post is a 1/2" IPS (3/4" CTS) Brass Compression Coupling.
 

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LiketoFix

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Did some more googling.... I think the pipe in question is brass. See OD chart below. The "dressing coupling" I referred to in my original post is a 1/2" IPS (3/4" CTS) Brass Compression Coupling.
I was getting ready to suggest that you check it for Brass pipe. Very common back in the day. Especially on commercial/industrial applications.

LTF
 

KenC

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.840 is 1/2" pipe size not tubing size. You may be able to find brass pipe fittings to what you need. Depending on the wall thickness of your pipe it may be possible to thread the cut piece with a standard die.

Not recommending it but galvanized iron pipe can be used for water, was back in the day a lot. I don't see brass pipe fittings locally larger that 3/8 pipe, finding 1/2 may be a challenge.

edit: McMaster-Carr has brass pipe and fittings if you strike out locally.
 
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branimal

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.840 is 1/2" pipe size not tubing size. You may be able to find brass pipe fittings to what you need. Depending on the wall thickness of your pipe it may be possible to thread the cut piece with a standard die.

Not recommending it but galvanized iron pipe can be used for water, was back in the day a lot. I don't see brass pipe fittings locally larger that 3/8 pipe, finding 1/2 may be a challenge.

edit: McMaster-Carr has brass pipe and fittings if you strike out locally.
There's not enough space right now to thread it. I can't even cut the pipe with my close quarters pipe cutters in there. I'm going to cut some of the copper pipe downstream of the brass pipe to get some play on the pipe. Then I might be able to get a wrench onto the pipe I actually need to repair and leave the brass pipe alone.

Regarding brass fittings I've noticed the same thing at home depot. Nothing above 3/8". Check out supplyhouse. I've been buying all my plumbing and some HVAC stuff from them.
 

mike93lx

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Regarding brass fittings I've noticed the same thing at home depot. Nothing above 3/8". Check out supplyhouse. I've been buying all my plumbing and some HVAC stuff from them.
I bought some 3/4 stuff at home depot to redo my water heater drain a couple weekends ago. Multiple *******, a 45, valve, not to ght adapter. They had tons of stuff in a range of sizes up to at least 1"
 
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KenC

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Yeah, there is a bunch of it. Been the same at every HD I've bought plumbing stuff at
That's odd, nothing over 3/8 at HD or Lowes here (OK).
Edit: now that I think about it, brass and copper where almost universally used in heating system before the plastics arrived on the scene. And there are almost no water circulating heat systems in OK, so it would make sense they wouldn't stock those things
 
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75gmck25

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In my HD the brass fittings and pipes are not located in the main plumbing area. They are in a back aisle where they sell water heater pans and flexible lines, flexible plastic tubing, washing machine hoses, home-owner grade P-traps and fittings, etc.
 

LiketoFix

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Real copper and brass pipe was the only thing used before the 60s legally in NYC. Just a warning, brass pipe has a tendency to break off at the threads once it is old. I had brass pipe in my 1901 house, every time I had to wrench it, it was scary. You were lucky if it did not break at the threads.
The old timers would put Vasalene/Petroleum Jelly on the threads as it stayed greasy, and kinda pliable for years down the road eliminating trouble with thee pipes breaking and snapping off at the threads. You are right though as this was a common problem. The pipe dope would get hard and crusty and wasn't good over a long time. Tapered plumbing pipe threads pretty much seal them selves without pipe dope but the Vaseline/Petroleum Jelly helped to seal also. ;)
LTF
 

southalabama

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Not to be a smart *** but it’s a Dresser coupling not dressing coupling. Dresser was the inventor and his were the original dresser couplings. Every other brand are compression couplings. Like calling all copies Xerox’s or tissue paper Kleenex. I learned to call them compression couplings after getting blank stares in the various hardware stores who didn’t know what a Dresser coupling was.


 

rlitman

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Not sure if this is a good or a terrible idea, but it just occurred to me that MegaPress makes stainless fittings for water with galvanized pipe, and since your brass is IPS OD sized, it might just work.
 
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