Teflon tape is also called “Plumber’s Tape” and “Threading Tape.” It’s a thin white tape that’s very stretchy. Teflon tape is commonly used on the male threaded ends of pipes before they are attached to female ends. It helps make joining the pipes together easier. It also helps prevent leaks from occurring at the joints. However, just like other plumbing products, if Teflon tape isn’t used properly, it won’t work effectively.
Wipe the end of the pipe clean with a rag. Make sure it's free from oil, dirt, grease and other debris.
Take hold of the end of the Teflon tape. Place it on the end of the pipe in the same direction the threads run. Hold the end in place with your finger. Continue to wrap a loop of the tape around the diameter of the pipe; let go of the end once the tape is attached.
Wrap a second loop around the pipe, overlapping the first loop by a half. Don't overlap it completely or you can apply too much tape. That can result in too much thickness which can interfere with the tape sealing properly. If it gets into the end of the pipe, the water pressure can also be reduced.
Proceed wrapping in the direction of the threads on the pipe end towards the length of the pipe. If you wrap it the other way, the tape won't stay in place. Wrap all the threads with the Teflon tape. As you wrap, keep a constant tension on the tape so that it is kept straight and taut. When you're finished using the tape, cut it from the roll with a pair of scissors. Press the cut end into the threads of the pipe to secure it.
Remove used Teflon tape by finding the loose end. Unwrap it from around the male end of the pipe in the opposite direction it was wrapped. Teflon tape can't be reused. It must be replaced with a fresh section of tape.