What describes a threaded connection in plumbing?

A threaded connection in plumbing is characterized as a joint formed by screwing the ends of pipes together. This method typically involves using Teflon tape or similar sealing materials to ensure a watertight seal at the threaded connection. The threaded design allows for easy disassembly and reassembly, making it a preferred choice for many plumbing applications.

The use of Teflon tape is particularly important in these connections because it fills the gaps between the threads, preventing leaks and enhancing the integrity of the joint. The ability to screw and unscrew fittings without specialized tools adds to the convenience of threaded connections in routine plumbing maintenance and repair tasks.

In contrast, the other options describe different types of connections that do not involve threading. For instance, union joints that require no tools provide ease of connection but are not defined by threading. Fused joints utilize heat to merge materials, which is a technique not applicable to threaded connections. Lastly, joints that can only be connected by welding are fundamentally different in their assembly and are typically used in specific applications that require a permanent bond rather than the flexibility offered by threads.