Threading on Valves to 3/4" NPT Male adapters before soldering?


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Old 11-02-19, 02:43 PM
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Threading on Valves to 3/4" NPT Male adapters before soldering?

I have a manifold that I am putting together for my apartment building. It is a 12 port manifold with 3/4" outlet ports. I would like to solder on male 3/4" NPT adapters so that I can use female threaded ball valves. Should I add pipe dope, tighten the fittings then solder them to the manifold so that all the valves are sitting in the correct orientation? I am thinking that If I solder on the adapters first then there is a chance when I tighten the valves onto the adapters they could end up in almost any orientation. My other concern is about getting the pipe dope too hot and breathing in some nasty fumes.
 
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Old 11-02-19, 05:27 PM
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Assuming this is for water and not natural gas, propane or #2 oil, this is what I'd do.

First of all, you never solder a threaded pipe connection. When installing the valves, to get the correct orientation of the valves, use teflon tape on the threads and tighten till they turn to that preferred orientation and stop. If you go past the preferred orientation you'll have to continue turning the valve till the correct orientation comes up again. If you go past and cannot get another full turn, remove the valve and start over with new teflon tape on the threads.

The 3/4" NPT adapters you speak of sound like close nipples. I'd use teflon tape on them too.
 
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Old 11-02-19, 05:42 PM
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CasualJoe,

Thanks for the response. I was not going to solder the threads. You can see a pic here of what I am attempting to do. I was just wondering if it was better to thread the valve on, before I solder on the threaded copper pipe adapters. This way all the valves will line up. Let me know if this makes sense...
 
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Old 11-02-19, 06:57 PM
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Just solder it how you have it with the valves just started on the threads and oriented correctly..

After all is done remove valves tape and dope and screw them on. They should all turn on pretty much the same.
 
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Old 11-02-19, 07:09 PM
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Lawrosa,

Thanks. You have helped me before, so thanks again.
 
 

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