When wrapping pipe threads with teflon tape (thread seal tape), what is the direction and recommended number of times to wrap the tape around the threads? Any other recommendations or tip/tricks when applying teflon tape?
Wrap clockwise - i.e. in the same direction as the tightening action of the nut. This means that you are also tightening the tape around the thread.
If you wrap anti-clockwise I find that the tape bunches up and comes away.
As for the number of layers - I usually wrap the tape around at least twice, maybe even three or four times.
For the correct number of times to wrap the tape, check the instructions on the tape package (that tiny little printing in white plastic you can barely read). It should tell you. Different manufacturers will have different specs on this (depending on the thickness of the tape).
I highly recommend the higher-density pink teflon tape. It is a tiny bit more expensive, but I have found that it stays put on the threads much better and seals better.
The pink tape I use (CFPC) says:
- 3 full wraps for pipes up to 1"
- 4 wraps for pipes 1" - 1.5"
- not to exceed pipes > 1.5"
Using too much tape is bad, too little is bad.
Oh, and ditto what ChrisF said about wrapping the tape in the proper direction!
Personally I would recommend avoiding teflon tape altogether and use TFE paste instead. It can be a bit messy, but aside from that it's pretty hard to do it wrong - just goop the stuff on there and screw it together.