Sharing China-Made with Global Customers
Sharing China-Made with Global Customers
Spiral submerged arc welded pipe coil forming method for the upward roll forming method, upward roll forming of various specifications of the bottom surface elevation of the steel pipe remains unchanged, so the ancillary equipment is simpler, easier to manufacture, civil engineering work is also small; but the height of the outer weld head to be adjusted with the change in the outer diameter of the steel pipe. When winding, the inner welding head is near the entrance of the strip, it can be easier to replace the conductive nozzle and other parts; and do not have to cut holes in the steel pipe, saving both steel and time.
Welding at the bite point facilitates the application of advanced technology of automatic weld gap control to ensure weld quality. In addition, it is easy to remove the iron oxide at the inner and outer pressure rollers, and it is easy to replace the spare parts. Therefore, at present, most spiral submerged arc welded pipe production lines are widely used in the top roll forming.
Forming seam when tight and loose, tight inside and outside loose or open seam defects cause analysis
Uneven strip width or strip edge condition is not good, easy to cause the forming seam tight and loose.
The height of welding pad roller is not high enough, which will easily cause the forming seam to be tight inside and loose outside.
There is no bevel or inverted bevel on the strip edge (the strip is wide at the top and narrow at the bottom), which causes the forming seam to be tight inside and loose outside.
The shape of the vertical roller is not suitable (usually the entrance of the former adopts slanting vertical roller), which squeezes the lower edge of the strip and causes the forming seam to be tight inside and loose outside.
The strip delivery condition is not good, easy to cause the forming seam inside tight and outside
loose, sometimes tight and sometimes loose phenomenon.
Open seam is usually due to the strip steel deformation is seriously insufficient, the working width changes too quickly or internal welding long distance welding bias caused by.
Spiral steel pipe is mainly used in water supply projects, petrochemical industry, chemical industry, electric power, agricultural irrigation and urban construction. For liquid transportation: water supply and drainage. For natural gas transportation: natural gas, steam, liquefied petroleum gas. For structural use: for pile pipes and bridges; for wharves, roads, building structures, etc.