The key to having a set screw fitting not fail is as Tom said, not setting the screw, backing it out, shift it a little, set it again, etc. And bury that screw. Spinning it until it meets the pipe is not enough, you need to bury the screw head into the shoulder. Think of it as a one time shot, position it, bury it.
I have always preferred set screw fitting because I have found so many loose compression fittings. I figured it was the result of expanding and contracting over the years. Inherant flaw in design and the fact that rather than having the tightness determined by something measurable (screw buried into shoulder) one must work from "ahh, at oughta do 'er".
[This message has been edited by Jps1006 (edited 11-28-2005).]
