1. The causes of the uneven wall thickness of the spiral shape are: the uneven wall thickness caused by the adjustment reasons such as the uneven rolling centerline of the piercer, the inclination angle of the two rolls, or the reduction amount in front of the plug is too small, generally along the

At present, the commonly used methods of steel pipe pipeline welding include electrode arc welding (SMAW), submerged arc welding (SAW), gas tungsten arc welding (GTAW), gas metal arc welding (GMAW), flux-cored arc welding (FCAW) and Downward welding, etc.(1) The advantages of electrode arc welding a

Technical requirements of straight seam welded pipe: Technical requirements and inspection of straight seam welded pipe According to the GB3092 "Welded Steel Pipe for Low-Pressure Fluid Transport" standard, the nominal diameter of the welded pipe is 6~150mm, the nominal wall thickness is 2.0~6.0mm,

The welding current in the swing welding of the straight seam steel pipe is slightly larger than that of the traditional welding method; secondly, the elongation of the tungsten electrode in the swing welding of the straight seam steel pipe is determined according to the pipe wall thickness, usually