Production process of elbow: Non-metallic single-welding

Production process of elbow: Non-metallic single-welding

These elbows are made from the steel plates, so it is not seamless steel elbows,  use a mould and press the steel plate to the shape of the elbow, then weld the seam to be a finish steel elbows, it is the old production method of the elbows.  Recent years the small sizes elbows are almost manufactured from the steel pipes now.