Procedure flow: 1.Raw material is loaded on feeding-in support by frame crane, do bevel processing by cutting & beveling machine or CNC plasma beveling machine according to different size and processing requirements. 2.Convey finished pipe by frame crane or trolley to multi-functional assembling workstation according to follow-up processing demands, assembling it and convey it to semi-finished material support. Those pipes without assembling demands go to next processing. 3.Convey Semi-finished pipe by frame crane or trolley to welding area according to processing requirements, do backing welding, cosmetic welding and automatic welding respectively. Convey it to the finished material support after welding.