Soldering cop. pipe in a “closed system”
akjim
| Posted in Construction Techniques on
Scenario: 1 inch copper LB leaked (hot water heat). Closed the nearest valves, cut LB with sawzall, drained, etc..
Problem: how to solder this LB. Valves on each side make it a “closed” system. No way for steam/pressure from torch to escape.
Advice?
Replies
Cut the pipe a few inches away from where your ell is and install a union. DanT
Drill hole in copper pipe about 1/8th inch diameter somewhere in the vacinity where you're sweating. Sweat as required. Put flux on/in hole and on a BRASS screw that will screw into hole. With screw screwed into hole, hit it with torch and solder. Voila. Have done this many times, still no leakers.
a pair of compression fittings would work, one on either side of the new ell
the system should have provisions for draining the water, which would allow you to repair using typical sweat couplings
You can also get a regular copper coupler with a weep valve (if you hunt around long enough). Install with valve open, then close valve. If you can't find the coupler, do the same thing with any sort of valve with a weep valve on it.
If there is enough air volume in the piping, the pressure may not be significant.
Or you can "preheat" the length of the pipe so that the air inside expands, then solder as it cools. You have to be careful, though, that the cooling air doesn't suck all the solder inside, leaving none in the joint.