What is the most common type of fitting used with copper pipe?

The most common type of fitting used with copper pipe is the socket fitting. Socket fittings are designed to receive the end of a copper pipe and are typically soldered or brazed to create a permanent connection. This type of fitting allows for a secure and leak-proof joint, which is essential for the integrity of plumbing systems.

Socket fittings are favored because they provide a larger surface area for the solder or brazing material, ensuring a strong bond. They are commonly used in various applications, from residential plumbing to heating systems, which further cements their status as a standard choice among professionals.

The other options, while important in various applications, are less universally recognized as the most common type when specifically considering connections with copper pipe. For instance, elbows are used to change the direction of piping, couplings connect two pipe ends, and sleeves serve to connect pieces of pipe but do not have the same level of prevalence as sockets in making primary connections in copper piping systems.