Teflon tape is best used as which of the following due to its characteristics?

Teflon tape is primarily used as a sealant because of its unique properties. It is designed to form a tight seal on threaded pipe connections, preventing leaks of gases and liquids. The tape is non-adhesive and works effectively under a variety of temperatures and pressures, making it suitable for plumbing and gas fittings. Its smooth surface allows for easier disassembly while also providing a reliable seal during operation.

The character of Teflon tape, specifically, its ability to expand and fill gaps between threaded surfaces, is why it is favored as a sealing material. While it does have some lubricating properties, its primary function in the context of instrumentation and piping systems is to act as a sealant, ensuring a leak-proof connection.