The concern here appears to be that you're using a threaded
shut off valve, and then thread to copper adaptors? I would
not want to put heat on a fitting that was already teflon
taped, and doped.
You may wish to cut the copper pipe a couple inches from the
valve. Install a copper union. This will allow you to solder
the thread adaptors onto the copper pipe, and then thread it
all together, later.
Hope one of those links work. You may need to cut and paste
the link into your browser.
Christopher A. Young
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