METHOD OF PREVENTION OF PIPELINE WALLS DEFECTS DEVELOPMENT Russian patent published in 2008 - IPC F16L57/00 

FIELD: technological processes.

SUBSTANCE: bending strains, which are detected by nondestructive check (NDC), are reduced to the minimum possible value on the part of the pipeline. Hoop stresses are reduced by tightening coupler's halves. When the coupler is installed, connection line of its halves is shifted relative to defect at the distance, which provides invariability of pipe metal properties in the area of defect during welding of coupler's halves. Antifriction material is applied in the zone of coupler sliding relative to pipeline, and friction properties are added to coupler and pipeline metal surface in the friction area. Tensile stress in the coupler is monitored, and coupler is tightened until tension is created in its central cross-section, which is equal to hoop stress of pipeline, and tension in the coupler ends is equal to half of hoop stress.

EFFECT: provides for optimal stress gradient in pipeline under the coupler and prevents defect growth and pipeline destruction.

8 cl, 2 dwg