Teflon® tape is a specialized type of tape used in plumbing to seal connections throughly, ensuring that pipes will not leak. This tape is also referred to as poly(tetrafluoroethylene) (PTFE) tape, with “Teflon®” being a trademark of the DuPont company. It is available at most hardware and home supply stores, usually in the plumbing section, and it is a standard part of the toolkit of people who do any sort of plumbing work.
PTFE is a very interesting substance. From a plumbing point of view, it's important to note that it is very flexible and that it has immense tensile strength. When Teflon® tape is used to wrap the threads of a pipe, the tape acts almost like putty, filling the space and preventing leakage. While it is possible to use plumbing putty for tasks like this, Teflon® tape is quicker and easier, and often much neater, as well.
Typically, PTFE tape is white, because this is the natural color of the substance. Some companies make color coded PTFE tape, with different colors being designed for different types of plumbing. The Teflon® tape used for gas plumbing, for example, is thicker to prevent gas leaks, and it may be coded blue or yellow. The tape is not adhesive, tending to cling with pressure but being easy to move and reposition.
This tape is designed for use in pipes with tapered threads. Tapered pipes are ideal for making a tight seal because the tapered design creates a wedge effect, sealing the pipe neatly so that nothing can leak out. To use the tape, a length is wrapped around the male or threaded end of the pipe, and then the female end of the pipe is connected. It is important to make sure that the Teflon® tape does not overlap with the end of the pipe, as this can cause problems in the future, because the tape may block the pipe.
Teflon® tape is a very useful thing to keep around the house. Even if a plumber will be consulted to fix a problem, the tape can be used for a quick fix to keep things contained until the plumber arrives. People should be very careful around gas plumbing, as gas leaks can be quite dangerous, and they need to be handled by professionals. If a gas leak is suspected, the gas should be turned off and a gas professional should be called immediately.