Standard:ASTM A106, ASTM A53, API 5L Gr.B, DIN17175,DIN1629 Boiler tube is open on both ends and has a hollow section, the length and the surrounding of the larger steel, according to the production methods can be divided into seamless steel pipe and welded steel pipe, steel pipe specification with overall dimensions (such as the diameter or length) and the wall thickness, said its size range is very wide, from small dia