What type of joint is typically used for connecting copper pipes?

A soldered joint is commonly used for connecting copper pipes because it creates a strong, durable, and watertight seal. This method involves melting a filler metal, usually a solder containing tin and lead or lead-free alternatives, at the joint between two copper pipes. When the solder cools, it solidifies and forms a bond that can withstand both pressure and temperature changes that are typically encountered in plumbing systems.

Soldering is favored for copper piping due to its reliability and the ability to produce smooth joints that facilitate the flow of water without risk of obstruction. The heat applied during the soldering process causes the surfaces of the copper pipes to oxidize slightly, allowing the solder to adhere well once it cools.

Other methods, such as welded joints, are generally not used for copper because welding requires higher temperatures that could damage the pipes, especially if they're thin-walled. Threaded joints are more suitable for use with pipes that have threading on one or both ends, typically for metals like steel rather than copper. Compression joints, while sometimes used with copper, typically use fittings that allow for quick assembly and disassembly without soldering, but don't create as secure a bond as soldered joints.