METHOD OF REPAIRING SAGGING AND DEGRADED PARTS OF UNDERGROUND PIPELINES Russian patent published in 2008 - IPC F16L1/26 

FIELD: construction.

SUBSTANCE: invention can be used for repairing mainline underground pipes whose parts are sagging or degraded on the riverbed with small water barriers. The ends of a pipe section are processed, flaw detection of the welding joints at the ends of the section is done, and then repairing of the joints is carried out. A trench is designed; stress is measured at the end cross-sections of the part of the pipe and in the cross-section of the pipe, over the nearest reference support shunt pipe to the cut pipe. If the stress in the end section of the pipe reaches the standard value, cutting of the support shunt pipes is stopped and the length of the open part is increased. Surcharge is applied in stages, with change in stress in the end sections. When the standard stress value is attained, surcharging is stopped and the length of the open part is increased.

EFFECT: increased durability of the pipeline.

5 cl, 3 dwg