How to use Teflon tape on pipe threads

PTFE ("Teflon") tape is great on tapered pipe threads. It's inexpensive, seals and lubricates the pipe threads, and is easy to apply.... oh wait, except for that last part.

Greg shows how to apply the teflon pipe thread so that it DOES go on easy and in the right direction, and doesn't unravel when you insert the pipe into the recptical.

Teflon tape is appropriate for pipe connections where the pipe is tapered. In these types of connections, the pipe threads make the seal. The tape helps lubricate the threads and improves the seal. Threaded joints where the pipe is not tapered (parallel threads) employ a gasket or washer to make the seal (such as on a union joint), in those cases, the tape serves no purpose, as the seal is made with the gasket, not the threads.

To quote
Commonly known as "Teflon tape", "PTFE tape", "tape dope", or "plumber's tape" — is a polytetrafluoroethylene (PTFE) film cut to specified widths for use in sealing pipe threads. The tape is wrapped around the exposed threads of a pipe before it is screwed into place. Since the PTFE is malleable, deformable and impermeable, it acts a little like putty under compression, being forced into small gaps between threads in order to create an air- and watertight seal when threaded into a joint. The tape is commonly used commercially in pressurized water systems, such as central heating systems, as well as in air compression equipment and thread joints with coarse threads.


Time to complete seconds
Materials teflon tape, threaded tapered pipe
Costs usually around a dollar for a roll of tape
Skill level Easy