Sweating a zone valve.


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Old 10-10-10, 04:32 AM
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Sweating a zone valve.

The sweat joint on one of my zones valves sprung a leak so I need to re-sweat it. Do I need to take it all apart before doing so? All tips would be appreciated.
 
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Old 10-10-10, 06:52 AM
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What do you mean by "take it all apart" ? You mean the valve itself? Take the guts out?

If you are thinking that you will be able to leave the sweat joints together and simply reheat the joint and have it seal up, I'm afraid that you will not succeed with that approach.

If a sweated joint leaks, it means that the joint was never properly done from the beginning, probably because the parts were not properly cleaned from the start. The points inside the joint where the water was leaking past are now 'corroded' to the point that the solder will not flow across them.

What you will need to do is take the joint apart, clean and re-flux, and re-sweat.

Any water left in the pipe will complicate the process. Chances are that you will need to use much more heat to get the joint apart than was used to put it together the first time. This extra heat will likely damage the ball and seals on the valve.

If you are able to get enough heat onto the valve to melt the joint, if there is any water left in the pipe it may cause the solder to shoot out in tiny little hot balls of solder. You don't want these getting in your eyes... WEAR SAFETY GLASSES!

Honestly, the easiest approach for you might be to purchase a new valve, cut the pipe, and replace the valve using 'repair couplings' (the ones without the pipe stop in the middle). I know it will cost a few bucks more but the chance of success is greatly improved.
 
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Old 10-10-10, 07:22 AM
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This valve is a year old and I have black pipe. Will taking the valve apart to protect it be a problem?
 
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Old 10-10-10, 07:25 AM
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Can I ask why to use couplings without the pipe stop in the middle?

I thought they were the best
 
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Old 10-10-10, 07:27 AM
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This allows you to slide the coupling all the way up to fit the new piece of pipe back in. Then you slide it down to solder.
 
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Old 10-10-10, 09:27 AM
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Originally Posted by drooplug View Post
This allows you to slide the coupling all the way up to fit the new piece of pipe back in. Then you slide it down to solder.

Sorry, I donít want to sound stubborn but I just donít see the reason for sliding this coupling all the way up to fit the new piece of pipe back in and then slide it down to solder.

And how you make sure that you have enough pipe inside the coupling when you slide it down to solder?

Isnít this action prone to mistakes?
 
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Old 10-10-10, 10:00 AM
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The reason is for repairs. You remove a section of pipe. Now you have to get a new section back in using two fittings. If you can't slide either side of the existing pipe to the side enough to fit the new piece and the couplings, then you need the couplings to slide out of the way. You can mark the pipe before you solder as to where the coupling need to be.

Let's say the couplings require a 1/2" of pipe to be inside them. Let's say you remove a 12" section of pipe. When you put a coupling on boths sides, you now reduce that space between the coupling to 11", but you need to insert a 12" pipe. Coupling without the pipe stop allow you to slide them out of the way to create that 12" gap to instead the new piece of pipe.
 
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Old 10-10-10, 12:52 PM
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Now I got it LOL, thanks for taking the time to let me know
 
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Old 10-10-10, 04:38 PM
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Droops, you could try it... what have you got to lose? If the valve is only a year old, you might just get by re-using the O-rings, etc... they should still be in good shape. But, it might not be a bad idea to order up a seal kit to have on hand, just in case.

Still, you're gonna hafta get the pipe out of the valve to clean the parts, so you are probably going to have to cut a pipe somewhere?

Yeah, you've got black pipe... so what did you do? Transition to copper for the valves, then back to black? Probly woulda made more sense to use NPT valves rather than sweat?
 
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Old 10-10-10, 06:30 PM
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Originally Posted by NJ Trooper View Post
Yeah, you've got black pipe... so what did you do? Transition to copper for the valves, then back to black? Probly woulda made more sense to use NPT valves rather than sweat?
I didn't do it, the plumber I hired did. He put a copper fitting that is sweat on one side and NPT on the other.
 
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Old 10-11-10, 02:47 PM
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So the valves are NPT on both ends, and there is black threaded into the valve on one side, and an NPT copper adapter on the other end that goes to the heating zone?

In that case, cut the pipe, unthread the copper adapter with the piece of cut pipe, measure and cut a new piece of pipe, buy a new adapter, sweat it together on the bench, use a repair coupling and thread the new piece back into the valve and sweat up the coupling. Wrap a wet rag around the valve if you are worried about the heat...

Why not take a pic so we can see wth you are working with there?
 
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Old 10-11-10, 04:10 PM
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I already completed the project. Not sure if the valve is ok, but I haven't done a full investigation yet. It is holding water though.

The valves are sweat valves. The copper adapter turns the sweat into NPT where my system pipe comes in. You will have to zoom in on this pic to see: http://flickr.com/gp/drooplug/31nH93
 
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Old 10-11-10, 05:13 PM
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Yeah, I see it now... the installer musta had a 'contractor pack' of those on his truck... and was cheaper for him to convert them to NPT with those adapters. Really, he shoulda taken the time to order NPT valves... but what do I know? I'm just the...
 
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Old 10-11-10, 05:40 PM
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Well I guess I overcooked something in the valve. The pipe for that zone gets warn when the DHW runs and the other zone stays cold.
 
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Old 10-11-10, 06:28 PM
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Probly melted it's balls...

Live and learn, eh?
 
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Old 10-11-10, 06:49 PM
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Old 10-11-10, 06:56 PM
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Yeah. Is this the seal kit? Maybe I can pick it up locally.
 
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Old 10-11-10, 07:03 PM
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Yep, I think it's the one for your valves, but check it out to be sure. You'll probly pay about $30 for it locally. PexSupply has it a teensy bit cheaper than Patriot. You can drive over to Plainview and pick it up too... save the shipping, but burn the gas.

You can see from the website that it's got the ball and O-ring... plus a few other goodies in it.
 
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Old 10-16-10, 12:25 PM
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I broke apart the valve and looked inside. Nothing was wrong. The ball looked fine and the seat was clean. Hopefully I'll remember where I put this seal kit for when I need it in 20 years.
 
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Old 10-16-10, 01:13 PM
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I also wasn't sure how you would get the old ball off either. Looks like the pin it is on is smashed over the sleeve to hold it in place.
 
 

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