Exterior galvanized to copper union - how? size?


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Old 05-21-20, 02:07 PM
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Exterior galvanized to copper union - how? size?

Hi, I'm going to attempt cut this pipe before it enters the ground, rerun the pipeline to the right (as indicated by my finger pointing) along the exterior of the house, and finish the line with a hose bib/spigot. (I've checked that the pipe is indeed water and not gas) I also understand that in order to run copper piping, a dielectric union will be needed. My questions:

1. Where's the most sensible place to cut the galvanized metal - with minimal dealings with the other joints - to connect to copper pipe? I guess I'm asking where I should put the union without having to do too much alteration to the existing pipe coming from the house? * See below, second image - should I run something as shown in orange, brown....or something else?

2. What size pipe is the pipe am I dealing with. I've measured the outside of the pipe and want to run 3/4" copper pipe.

Thanks in advance for the advice and assistance.


Should I run the copper as shown in the brown route, orange route, or some other route?

 
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Old 05-21-20, 04:11 PM
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I would whack the galvanized 4-6" away from the elbow in the wall. That will leave you a good 4-6" to hold onto and unscrew the galvanized nipple from the elbow. Then you will have the option of transitioning to your copper there on the horizontal or you can then unscrew the cast iron elbow and make the transition a little bit inside the wall and not have the piping make a U turn.

The nice thing about unscrewing the 4-6" of pipe nipple that you just cut is you are in a strong position to unscrew it from the elbow. It's a good idea to hold the elbow with a wrench but the pipe orientation will help hold it for you. If you try to unscrew the elbow you MUST hold the pipe that's in the crawl space.
 
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Old 05-21-20, 05:38 PM
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Thanks, Pilot Dane. I understand your advice. I'll probably run a copper route like the brown path in my bottom image above. I don't want to do mess with too much under the home nor get into an issue over my amateur head. Don't want to have the house water off longer than necessary..

Would you know what size pipe I'm dealing with?
~ 3/4", correct?

Thanks for your reply!
 
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Old 05-21-20, 06:55 PM
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Looks like 1/2" pipe. OD of steel pipe is 0.84".
 
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Old 05-21-20, 07:29 PM
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Looks like 1/2" pipe. OD of steel pipe is 0.84".
Awesome. Thanks for your insight, Zorfdt
 
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Old 05-22-20, 09:06 AM
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What’s the purpose of transitioning to copper for a few feet? Seems like that just makes the job harder. Don’t you just want to tee into the existing water line and run a pipe to the right with a spigot on the end? Don’t see how you can force that elbow away from the wall without destroying the current piping.

I thought the pic shows pipe coming up from the ground, turning right along the outside wall, and then turning into your house though that opening – and you still want that. But I guess I misunderstand.

(OK looking again - that orange line looks like a tee, but now I think that's not the case and you are doing a replacement and not a tee and the current piping isn't necessary - I guess lol)
 
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Old 05-22-20, 03:50 PM
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Hey Zoesdad. I assumed I shouldn't use galvanized again and was considering copper.
I went looking for information regarding plumbers tape and dielectric union and read the unions are worthless. Now I'm considering PEX. It's a bit overwhelming for an amateur and I stress a little about having the house water off for too long and getting in over my head.

I don't want to fiddle too much with the existing galvanized nor do I desire crawling under the house to access the pipe (the trapdoor is in my son's room's closet and under a ton of stuff I have no desire to relocate while he's out of town). So I don't mind a bit of excess copper (or PEX) to reroute to the spigot as described in my original post.

Thanks much for your input and reply. Appreciated.
 
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Old 05-22-20, 07:02 PM
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I went looking for information regarding plumbers tape and dielectric union and read the unions are worthless.
What's worthless about them, I've used dielectric unions a number of times with no problems. For me dielectric unions are standard on any water heater install I do.
 
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Old 05-23-20, 07:10 AM
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I would do copper and dielectric unions in this case. You could alternatively use brass fittings since it's a pretty short span, but they do get pricey.

I would also use a or 6ga copper wire jumper between the two galvanized pipes with ground clamps. Depending on your electrical setup, your water line is likely being used as your ground. By adding dielectric unions, you're breaking that path. To be extra safe, I would add that jumper before cutting the pipe. There's a rare (but possible) chance that there's current through that ground, and by adding the jumper, it ensures you won't become that path.
 
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Old 05-23-20, 08:20 AM
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N3V Ė

You are correct as far as I know; you should replace galvanized steel wherever you can. It rusts from the inside out (Iíve had some unbelievable galvanized steel pipes).

I admit I donít understand what you are doing (I donít mean that sarcastically, I can be thick LOL)

But -

(1) If this new pipe is in fact outdoors, you cannot use PEX outdoors. The UV rays destroy it. It is not rated for outdoors.

(2) If you use copper you will HAVE to solder adapters (that would include unions) onto the copper pipe to connect to the galvanized steel. Copper pipe does not come threaded. Just mentioning that because it sounds like you might not have soldering experience Ė yet!
 
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Old 05-28-20, 11:23 AM
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nevermind. I figured out what is required!
 

Last edited by N3V3R D0N3; 05-28-20 at 12:40 PM.
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Old 05-29-20, 04:09 PM
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N3V-

Glad you got it figured out. I was playing around with the problem and here is my pic while I was brainstorming , but Iím not sure it would have worked.

I think the transition to copper makes it hard, and definitely requires soldering. Also, I donít know whether there is enough room for the unions against the wall. Looks like it though.

Also I think you should be able to replace the pipe between the elbows with a union and nipples as in the pic Ė but Iím not sure. The length of the new union plus the new nipples has to be exactly the same length as between the current elbows. Not sure if that is doable. (Plumbers probably pee their pants laughing at this Ė lol. Moe, Larry, Curly special lol)

https://imgur.com/uG78yUF
 
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Old 05-30-20, 01:17 PM
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Zoesdad - wow, man! Thank you for the diagram! Much appreciated. I missed your post yesterday as I spent the day finally tackling the problem. (I abandoned the line leading into the ground as I didn't want to deal with the run of severely corroded metal pipe .

You guys can laugh or critique my work folks, but me and my sons got 'er done and we now have a water source in the backyard. Again, I didn't want to mess with the length of metal pipe running under the house, nor did I want to have to go in the crawl space and deal with that dusty nightmare. Hence, the u-turn of copper route that I created.

Everything was going smoothly until we went to weld together the elbow and spigot section (bottom right picture). I think we were working too fast and achieved to much heat among the close joints. We kept getting leaks and trying to repair it with moisture in the line as well as not enough cool down time. I eventually just started again, recreating the section with a longer section of pipe between the elbow and hose bib. We finally got it done, but Is still need to complete securing the copper line to the exterior stucco wall. Thanks guys for all the help, input, suggestions, and diagram by Zoesdad!
 
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Old 05-30-20, 02:43 PM
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Well looks good to me! Looking at soldered copper like that just gives you a warm fuzzy that nothing is going to go wrong with that - ever. (I think there is copper piping out there in some places that’s over 80 years old). My house has copper and I plan to keep it that way.

One trick I learned on this forum is to wrap a damp or wet rag around a joint that’s too close to the joint you want to heat. I found that really works.

I know what you mean about getting dampness in a pipe that you are trying to solder. It’s a nightmare. I guess the truth is it really can’t be done. (I had a well tank once from which no way no how could I get out the moisture, even with the tank upside down lol - so I had to give up trying to solder and use a Sharkbite instead). Somehow the moisture has to come out. But looks like you have that problem licked now.

The problem I used to have sometimes was soldering brass valves and things that were very heavy, using a propane torch. I guess because it is much harder to heat the thick connection. But then I heard on this forum that MAPP gas is the way to go. So I got a MAPP torch at Home Depot and was surprised how much easier it is to solder valves and things. It heats so much faster and seems so much easier to get the right amount of heat. It seems so much easier with MAPP.

Looks like you have it made now. Copper looks good against the house in your pics. Good Luck!
 
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