What is the process of expanding soft copper to relieve another piece of copper of the same diameter called?

The process of expanding soft copper to relieve another piece of copper of the same diameter is known as swaging. Swaging involves the mechanical deformation of metal to enlarge or reduce its diameter and shape. This technique is commonly used in HVAC applications when joining pipes or creating fittings that require a snug fit without the need for additional soldering or welding.

In swaging, a tool applies pressure to the copper, allowing it to expand or contract as needed. This process ensures that the two pieces of copper can fit together securely and can withstand the pressures and conditions they are subjected to in HVAC systems.

The other terms relate to different processes. Flaring is the act of expanding the end of a pipe into a bell shape, often used for making a secure connection with a fitting. Brazing involves joining two metals together using a filler metal that has a lower melting point than the workpieces, while coiling refers to the process of winding copper into coils, usually for storage or use in systems that require flexible tubing.