On Mon, 11 May 2009 10:28:22 -0700, Pilgrim
wrote:

What do I need to know and what precautions do i need to take to sweat
solder a 1/4 turn ball valve in 3/4" Cu pipe? The ball turns in a
plastic seat that looks like teflon.

Thanks in advance.

Chuck P.
I just had to do this several times a few months ago. I cleaned the
valve and pipe well with a wire brush made for the job, used plenty of
flux, and heated the joint quickly. I use an air/acetylene torch for
plumbing work because it's so fast. Make sure the torch you use is big
enough for the job. Heating the joint fast and getting the solder in
quickly gives the heat less time to travel to the rest of the valve.
The brass that the valve is made of transmits heat much slower than
pure copper so this is why fast heating is best.
ERS