Oh, I disagree. If you double wrap the safety wire so that it forms a complete circle around the line which tightens when you twist it, it certainly does increase the pressure between the tubing ang the nipple which will help prevent leaks. It works just like a cable clamp...

In addition, in a lot of installations, there are air lines with tee's or fittings, that wind up near the turbine or tailpipe and these can easily leak when the tubing gets warm and loosens its grip on the nipple - even if it doesn't actually come off the nipple. Safety wiring these will also greatly reduce the occurence of leaks.

Bob