This system is intended to improve the production efficiency through automation of inside welding in the single pipe manufacturing process during the whole process and, by applying the 3poles SAW technique and the high precision seam tracking system to Longitudinal Seam Inside welding of the single-pipe member supplied with bending and fit-up, it is designed to allow continuous operation from Arc Start to the end of operation. The basic composition consists of a fixed type Manipulator with welding system and a Turning Roll for weld driving and member support. In addition, the automatic flux spraying and recovery system is composed of Filtering and Heating System for continuous Flux supply, recovery, and the reuse of recovered flux, and continuous welding is possible.