Distance to solder?

[waynrayn]

Hi There:

I'm new to this forum, first posting...

A DIY question: I am installing a new hot water heater. It's ready to go, and I am dry-fitting the copper (3/4") piping above.

The nipples on top of the heater specify that no heat should be directly applied, as they have plastic inside. Soldering the pipe separately to a fitting, then screwing it onto the nipple with plumbing tape is not a problem.

However, I will have to solder the pipe past that at some point. I am wondering how close I can solder without getting the nipples too hot and damaging the plastic inside. For example, I need to make a 90-degree turn no more than 10" away from the first connection to the nipple.

Given how hot the copper pipe gets, this still seems awfully close. Questions going through my mind are how to keep the pipe cool? Should I use MAPP gas instead of propane, because it's faster (I now have a cheap propane torch)?

Any advice as to proper minimum distance to solder from the nipples, and how to keep the pipe cool, and whether MAPP should definitely be used, would be appreciated.

Thanks & regards,

Wayne

 

[Matt30]

Map gas burns hotter. If you are not very experienced in soldering, propane will be your better option.

The correct way would be to do like you said and solder a piece of pipe into the female adapter, then screw it on. At 10", you will be fine to solder the rest. Wrap a wet rag around the nipple.

Soldering is a bit of an art form in itself, as you get more comfortable with your torch control you can solder without heating the fitting up so much. I have successfully soldered the top of a Marathon hot water tank 2" away from the dip tube without damage, but that definitely wasn't my first kick at the can

 

[waynrayn]

Thanks, that's a clear answer for a novice.

Amazing that you could successfully solder that close to a water heater nipple!

Impressed...

Cheers,

~W~

 

[Matt30]

Good luck with your project. Come back and post pictures of the finished product!

 

[frodo]

wrap a wet rag around the fitting you do not want to get hot.

 

[Mr_David]

you can use di-electric unions or use a copper wtr htr flexs supply union screws onto nipples and sweat the other end to pipe.

 

[waynrayn]

Hi All:

I completed my first attempt, but am finding that the fittings on the water heater nipples are dripping slightly (although I taped them). This sounds like a novice mistake- not tightening the fittings enough- but there was a reason for this.

I had originally really cranked them on tight, then aligned the piping above to fit, then removed everything and soldered it together, leaving only a connection or two far away. This was to avoid being too close to the nipple. However, after soldering I found that although everything came together, when I put them back on the bottom fittings seemed to be not as tight on the nipples. Don't know why.

Anyway, I'll need to make a second try. I've included some pictures below.

The first shot is my completed attempt. I would be very happy with it if the bottom fittings were not leaking around the plumbing tape.

As you can see, both vertical portions are quite close to the top of the heater- only 5-6 inches above.

The last picture with the ruler is most important. I can again solder vertical pipe into the bottom fitting separately from the heater, then put it tight on the nipple. But the next joint up, the bottom of the T-junction, is still very close- just a little over 3 inches above- and I have to solder this one where it is this time.

So my question is, if I thoroughly wrap a wet towel around the nipple and lower pipe, will I be able to solder the bottom of the T-junction safely, without damaging the plastic in the nipple? I know Matt30 said he did it once only 2 inches away. Do I have a fighting chance?

Regards,

Wayne

 

[frodo]

you said it was dripping. you turned the water on? dos the line have water in it?

you need to get rid of any water, you can not solider with a wet pipe.

i would suggest, that you open the drain valve on the bottom of the heater.

why the vacuum breaker? why is installed on the cold line?

 

[waynrayn]

Hi Frodo:

I turned the water on to test what I had done. The solder was fine, just the nipple fittings are giving me grief. Live and learn.

I'll be removing most of what you see in the pictures. Round two. Almost all the piping will be new, except toward the back. I'll basically repeat what I've done.

The heater, which is new, is almost empty. I didn't put much in it.

The vacuum breaker is code in Canada. It has to go on the incoming pipe in case of reverse siphoning. Expansion tanks are on their way to becoming code here too- they already are on gas heaters- but none of my friends or relatives has one yet, so I didn't bother.

~W~

 

[frodo]

your solider job looks good, i am concerned that you may have over tightened the fittings, you said you """I had originally really cranked them on tight, then aligned the piping above to fit, then removed everything and soldered it together, """"

copper is soft, the nipple is hard, you may have stretched/distorted the fitting, throw away the teflon tape. use a pipe dope
like recto seal yellow #5


to remove the pipe instead of cutting it

here is a tip, heat the 90, pull the pipe loose. while the pipe is hot, using your gloved hand, wipe the molten solider off of the pipe
and, using a fitting brush, remove molton solider from inside the 90.

by removing the solider, you will be able to put them together again with out a lot of trouble

 

[Matt30]

I'm actually quite impressed with the soldering job. I was expecting to see runs all down the vertical pipe. Good job!

 

[Caduceus]

Most of those water heater nipples have about eleven threads and there appear to be maybe seven visible in your picture. When tightening, use some PTFE tape with a little pipe dope for lubrication to be sure you're threads are going deep enough into the female adapter. As for the thermal expansion tank, you appear to have some soldering skills, so why not put one in now during the project. It's not a matter of code, but more about protection of your fixtures and appliances. If you have a pressure regulator and/or backflow preventer on your water service then you will have thermal expansion. If you go that route, tips for proper installation are available here on the forum.

 

[Mr_David]

Hi All:


So my question is, if I thoroughly wrap a wet towel around the nipple and lower pipe, will I be able to solder the bottom of the T-junction safely, without damaging the plastic in the nipple? I know Matt30 said he did it once only 2 inches away. Do I have a fighting chance?

Nice soldering.

You should be fine with wrapping the copper fitting on the nipple.

You don't have to crank them down super tight.
I agree with Cad, Teflon tape with a little paste for lubricant. If the water heater is already full of water and the nipple is holding water you won't even need to wrap it. But if your valve to the heater is closed, you won't have enough air space in the line to prevent pressure inside the line from blowing out your solder joint as you weld it. If the valve is open and the main water is off you might be okay, otherwise you may have to drain the tank some.