Air acetylene is the hot ticket, or mapp or propane with a Turbo tip.
Do not waste time to disassemble the valve.
Clean valve with wire brush. And Copper with emery cloth. Cleaning is the
most important step.
Use Self cleaning flux. It is stronger and cleans better.
Sweat them the same day that you clean them.
Heat the valve at the fitting only, not the pipe. Sweat other end
immediately.
Heat only enough to get solder to flow. Heat opposite sides of the joint or
on larger tubing heat around the perimeter keep torch moving do not Dwell in
one spot. You can actually get it hot enough to burn the flux. And the joint
will never sweat properly unless you take it apart and re clean it.
Get in and out quickly. That is where the air acetylene comes in. The turbo
torch with propane is acceptable up to about 3/4 Diameter.
Start counting in your head as soon as you apply the heat. after doing a
couple you will get the feel for it and you can do them pretty fast. If you
burn the seal you got it waaaay too hot.
If you have to wipe the joint you used too much solder. It should have a
small fillet.
Good luck.
RR


"Proctologically Violated©®" wrote in message
...
Awl--

Hopefully my last plumbing Q! Man, am I buried here!

I have previously screwed up sweating ball valves, and frankly don't see
how the teflon seals withstand the heat, even with "good technique", which
mine most likely is not, given the rare plumbing that I do.

So what I do is buy threaded ball valves, and separately sweat a suitable
length of copper pipe to copper adapters, screw those in to the threaded
valves, and continue sweating some safe "thermal distance" from sed ball
valve.
Sometimes I'll even use a union, depending...

Am I bein a wus?? Is there a more reliable way to sweat ball valves?
I know there is some precedence for this, as I have seen sweat valves w/
removable flange-type ends, presumably for just this problem--but of
course they cost big(ger) $$.

In general, I sort of mix threaded w/ copper, like for caps: Instead of
sweating a cap to a tee, I'll first sweat an adapter, and then screw on a
threaded cap--makes subsequent connections easier, I think. I always
found sweating previously-wet copper "in line" a real pita.

Also, along the lines of ball valves, I noticed diff. 1/2 threaded valves
have diff IDs!
Gas ball valves have the smallest, but a nice thumb-handle. Can I use
these for water, as well?
Water ball valves have the longer handle, but even these have diff. IDs,
which I find surprising. Any idears on why? Just diff. mfrs?

A'ight, thanks! I hope this it, fer plumbing!!

----------------------
Mr. P.V.'d
formerly Droll Troll