Copper pipe fittings are connectors used to connect copper pipes. They are downstream processing products in the copper pipe industry chain, used for pipe assembly through methods such as socket welding, threaded connections, flange connections, or quick-connects to meet various engineering needs.

Classified by function, copper pipe fittings mainly include sleeve fittings (connecting two straight pipes), reducers (connecting pipes of different diameters), elbows (such as 90° or 45° elbows, used to change the direction of pipes), tees (for pipe branching), and cross fittings (for cross-shaped branching). According to material classification, copper pipe fittings can be divided into three categories: red copper, brass, and bronze. Red copper pipe fittings (such as T2 or TP2) have a reddish color, good ductility, and excellent thermal and electrical conductivity, and are commonly used in plumbing, refrigeration, and heat exchangers. Brass pipe fittings (copper-zinc alloys, such as H59 or H62) have good mechanical properties, are easy to machine, and are corrosion resistant, making them the most widely used type, especially suitable for plumbing, gas, and sanitary ware. Bronze pipe fittings (containing copper, tin, phosphorus, etc.) have high strength, are wear-resistant and corrosion-resistant, especially resistant to seawater corrosion, and are commonly used in shipbuilding, chemical, and heavy machinery. According to connection methods, copper pipe fittings include threaded connections (connected by tightening internal and external threads, suitable for low-pressure systems such as water pipes or gas pipes), socket welding (the pipe is inserted into the socket and welded, providing high connection strength and good sealing, suitable for high-pressure and high-temperature systems such as refrigeration or hydraulic oil pipes), flange connections (connected via flanges and bolts with a sealing gasket in between, suitable for large-diameter pipes or pipes that require frequent disassembly), and quick connections (such as compression fittings or quick-release fittings, designed with snap-fit ​​or locking mechanisms, allowing for quick connection and disconnection without tools, commonly used with pneumatic tools or in situations requiring frequent disassembly and assembly). Copper pipe fittings are mainly used in refrigeration appliances, building water supply systems, automobiles, ships, and seawater desalination. In the construction field, they have been used in the water supply systems of projects such as the Great Hall of the People and the National Centre for the Performing Arts in Beijing. With the improvement of air conditioning energy efficiency standards, the use of copper pipe fittings in heat exchangers has increased, with air conditioning and refrigeration equipment accounting for approximately 75% of copper pipe consumption.