Ptfe tape uses
First, use the soft bristled brush to thoroughly clean the male and female threads to remove all previously applied antiseize compound or tape. Use 1/4 inch wide tape on 1/8 inch, 1/4 inch, and 3/8 inch male tapered pipe threads. Use 1/2 inch wide tape on 1/2 inch and larger male tapered pipe threads.
Wrap the tape in the direction of the thread spiral of the male pipe thread beginning with the first thread. Tape should never extend beyond or overhang the first thread. If it overhangs, the tape could shred and get into the fluid system.
ptfe tape While keeping the edge of the tape parallel to the face of the fitting, wrap two to three revolutions of tape. The number of revolutions depends on the thickness of the PTFE tape you are using. Swagelok PTFE tape is thicker than the average hardware store PTFE tape, so two to three revolutions is enough. If you are using thinner tape, you will need to apply more tape. Draw the free end around the threads tautly so that it conforms to the threads.
When you have wrapped enough tape, cut or tear off the excess tape. If the tape does not lie flat, firmly press the tape into the threads. Now tighten the male end connection into the mating female end connection until finger-tight. Then tighten the male end connection until wrench-tight.
Once the connection is tight, do not loosen it. Doing so could mean leakage at the pipe thread. That’s all there is to it.