Pipe fittings are parts related to pipe connection. According to the connection method, it can be divided into socket pipe fittings, threaded pipe fittings, flange pipe fittings and welded pipe fittings. Mostly made of the same material as the tube. There are elbows, tees, crosses (cross heads) and reducers (big and small heads). Elbows are used where the pipe turns; tees are used where the three pipes come together; tees are used where the four pipes come together; reducers are used where two pipes of different pipe diameters are connected. This topic brings together standard information commonly used in pipe fittings for reference by the industry.