Spiral buried arc tube rolling tube forming method is the first roll molding method
At the time of the upper volume, the bottom surface of the steel pipes of various specifications is unchanged, so the subsidiary equipment is simpler and easy to manufacture, and the amount of civil engineering is also small. At the time of the roll, the internal welding head is near the entrance of the band, and it can be easier to replace parts such as conductivity. It is not necessary to cut holes on the steel pipe, which can save steel and save time.
Welding at the occlusion point is convenient for advanced technologies to automatically control welding gaps to ensure welding quality. In addition, it is easy to remove iron oxide skin at the inner and external pressure rollers, and it is easy to replace spare parts. Therefore, most of the production lines of most spiral buried arc welded pipes are widely used.
After the 1980s, the formation method of rolling was basically eliminated.
Analysis of the cause of the cause of loosening, tight and outer pine or opening defects when the formation seams are tight
(1) The width of the steel work is uneven or the edge of the steel edge is not good, which is easy to cause the formation to be loose tightly.
(2) The height of the welding cushion roller is not enough, which can easily cause tight and outer loosening in the forming seam.
(3) The edge of the band steel does not have a slope or there is a pouring mouth (with the width and narrow on the bottom of the steel), causing tightly loose and outer loose in the forming seam.
(4) The shape of the vertical roller is inappropriate (usually the oblique roller is used at the entrance of the molder), and the squeezing belt with the lower edge of the steel will cause the inner and outer pine of the forming seam.
(5) Poor steel delivery status is not good, which can easily cause phenomenon of tight and outer loose inner and outer inner and outer and timely loosening.
(6) The opening of the seam is usually caused by serious insufficient deformed steel deformation, too fast work width, or internal welding long distance welding.
Spiral steel pipes are mainly used for water supply engineering, petrochemical industry, chemical, electricity, agricultural irrigation and urban construction. Used for liquid transportation: water drainage. Natural gas transportation: natural gas, steam, liquefied petroleum gas. Structural use: for pile tube and bridge; for docks, roads, building structures, etc.
