Elbow, which is made by stamping a half-ring elbow from a plate of the same material as the pipe, and then welding the two half-ring elbows together to form a complete shape. Due to the different welding standards for various pipelines, it is usually shipped as semi-finished products with spot welds fixed in pairs, and the welding is performed on-site according to the pipe weld grade, hence also known as a two-piece welded elbow.