Pre-welding Quality of Straight Seam Steel Pipe

The preweld quality of straight steel pipe includes weld quality and weld quality.
(1) when the joint (i.e. the forming joint) has no wrong side or the wrong side is less than the specified value, the general error is less than or equal to 8%, and the maximum is not more than 1.5mm.
(2) in order to ensure the suitable penetration depth and welding amount of the weld, it is necessary to ensure no cracking after welding, no burning phenomenon, and the height of the weld. There is no effect on the weld seam height.
(3) continuous weld and good shape to ensure the final external welding quality.
(4) there are no defects such as welding deviation, blowhole, crack, slag, welding and backing welding. The weld center deviation is less than 1mm.
(5) no electric arc burns, little splash, no influence on pipe end groove and surface quality.
(6) the weld metal is matched with the base metal, and the physical and chemical properties of the weld metal conform to the quality requirements.