double-sided submerged arc welded pipeSlag protection is used, but this slag is not the skin of the electrode, but the welding flux specially melted. The flux system consists of a funnel-loaded flux delivered through a pipe to the front face to be welded. This is completely automated.

Use welding wire instead of welding rod, because the welding wire can be fed continuously; when there is a covered electrode, when burning the covered electrode, there must be a covered electrode head and throw it away. The operation must be stopped, replaced by a welding rod, and then welded. After the welding wire is replaced, the welding wire is continuously fed by the wire feeding device and the welding wire disc. This welding method is to ignite the arc under the coverage of the continuous feeding of the welding wire in the molten granular flux, so that a part of the welding wire, the base metal and the flux melt and evaporate to form a cavity, and the arc burns stably in the cavity, so it is called submerged arc automatic welding. The arc is buried in the cavity.

Because it is submerged arc welding, so the heat exchange and protection performance is relatively strong, welding product quality is relatively high. Moreover, submerged arc welding can use large current because the arc is buried under the flux, and the welding efficiency is relatively high.

Double-sided submerged arc welded pipe is a seamed steel pipe made of steel plate or steel strip after crimping and forming. It has the advantages of small size deviation, uniform wall thickness, simple production process, high production efficiency, many varieties and specifications, and less equipment investment. However, because the welding performance of welded steel pipe is lower than that of seamless steel pipe, its utilization rate in petrochemical equipment is very low. Double-sided submerged arc welded pipe is divided into straight seam welded steel pipe and spiral seam welded steel pipe according to the form of weld.

With the development of modern industrial technology and the progress of welding and inspection technology, the weld quality of welded steel pipes has been continuously improved, and the varieties and specifications have also increased day by day. When the pipe nominal diameter DN≥ 600, the production of seamless steel pipe has been more difficult, welded steel pipe instead of seamless steel pipe has become the main choice of fluid transportation.

　　double-sided submerged arc welded pipeAdopting advanced double-sided submerged arc welding technology, it can realize the best position welding, which is not easy to appear wrong side, welding deviation, incomplete penetration and other defects, and is easy to control the welding quality. During the forming process, the steel plate is deformed evenly, the residual stress is small, and the surface is not scratched. The processed spiral steel pipe has greater flexibility in the size range of diameter and wall thickness, especially in the production of thick-walled pipes, especially small and medium-sized thick-walled pipes, which has incomparable advantages over other processes and can meet the needs of users. More requirements for spiral steel pipe specifications. The 99.% quality inspection of double-sided submerged arc welded pipe is carried out, so that the whole production process is effectively inspected and monitored, and the product quality is effectively guaranteed.