METHOD FOR REPARING GAS PIPELINES WITH STRESS-COROSION CRACKS Russian patent published in 2008 - IPC B23P6/04 B23K9/16 F16L55/18 

FIELD: technological processes.

SUBSTANCE: after preliminary cleaning of defective part of surface of pipe by an abrasive wheel, the edges of the cracks are determined using penetrant flaw detection method and the defective part is then melted by an unsmeltable tungsten electrode. The process of melting starts and ends 10-15 mm from the beginning of the crack and after its end with formation of a depression with fused edges. The obtained depression filled along its whole length by an argonarc method with a filler wire. The surface is then cleaned, flush with the main metal and quality is controlled using ultrasonic flaw detection. Subsequent hardening is carried out using ultrasound pulse processing of the cleaned surface. The method reduces labour intensiveness of the repairing pipes which are in use and with defects in form of stress-corrosion cracks.

EFFECT: increased longevity of gas pipelines.

4 dwg, 1 ex