What is a pipe union typically used for?

A pipe union is specifically designed to connect two sections of piping together in such a way that allows for easy disconnection when maintenance or repairs are needed. This feature makes unions particularly valuable in plumbing and mechanical systems where flexibility in connecting and disconnecting sections is required. Unlike other fittings, unions are constructed with three pieces: two end pieces that attach to each section of pipe and a central threaded section that joins them. This design allows for a strong, leak-proof connection while still permitting easy disassembly without cutting the pipe, which is essential for maintenance tasks.

The focus of a pipe union is primarily on enabling quick and efficient connections rather than on functions such as terminating a pipe run, offering vertical support, or reducing pipe diameter, which relate to other types of fittings and connectors.