METHOD OF WELDING REPAIR CONSTRUCTION TO PIPELINE Russian patent published in 2018 - IPC F16L41/02 F16L55/17 B23K9/02 

FIELD: technological processes.

SUBSTANCE: invention relates to the field of repair by welding of pipelines of underground and above-ground gaskets, and specifically to a method of arc welding of fillet weld seams of repair structures when installed on pipelines of controlled rolling pipes. Method includes cutting the edges of the ends of the repair structure for welding and installing the repair structure with a gap between the pipeline and the structure from 3.0 to 5.0 mm. Preheating of the ring edges at the ends of the repair structure for fillet welds is carried out in the temperature range from 130 to 150 °C. Then, welding of the longitudinal and annular welds of the repair structure is performed successively. Arc welding of the ends is carried out with the formation of an annular fillet weld around the entire perimeter of the pipeline. Fillet weld is formed by overlaying weld overlay and filling beads. Installation of welded surfacing rollers is carried out so that the extreme welded roller does not overlap the filling rollers. After applying the filling rollers along the contour of the fillet weld, an additional weld bead is applied. Maintain the temperature of the cooling between the overlaid weld rollers in the range from 130 to 170 °C, then the corner weld is cooled at a speed of no more than 40 °C/s by continuous concomitant heating up to 170 °C. Further cooling is performed by covering the insulating belts to a temperature of 50 °C.

EFFECT: improving the reliability of the welded joint when performing welding work by obtaining a metal structure on the fusion line and in the heat-affected zone of the welded joint with a viscous component of at least 80 %, which leads to an increase in the bearing capacity of the pipeline.

1 cl, 1 dwg, 3 tbl