Polytetrafluoroethylene (PTFE) thread seal, commonly available as a white, non-adhesive film wound onto a spool, is used to create airtight seals between threaded pipe joints. It is applied by wrapping the film around the male threads before assembly. The film fills gaps between threads, preventing leaks of liquids and gases.
The application of this sealing film offers several advantages. It is chemically inert, resistant to a wide range of chemicals, and effective across a broad temperature range. Its use eliminates the need for messy pipe dope or other sealants. Historically, it has provided a cleaner, more reliable method for ensuring joint integrity in plumbing and industrial applications.