METHOD OF EVALUATING STRESS-STRAIN STATE OF A PIPELINE WITH FAULTY WELDED JOINTS Russian patent published in 2018 - IPC F16L1/28 F17D5/00 

FIELD: pipes.

SUBSTANCE: invention relates to the operation of trunk pipelines and can be used in estimating the stress-strain state (SSS) and the residual life of faulty welded joints, detected during in-line diagnostics. Method of estimating the SSS of the curved sections of the main pipeline with faulty welded joint includes the calculation of stresses in the pipe wall taking into account the bend radii of the pipeline axis. Evaluation is performed according to the data of in-tube diagnostics, in which the convex, concave sections and sections of horizontal rotation with non-projected elastic bend radii of less than 1000D minimum radius of elastic bending during laying, where D is the diameter of the pipeline. Separately, for each type of curved section, the elastic bending radii allowed for the yield point ρ_min at a given internal pressure and temperature difference. Stresses in the pipe wall are calculated taking into account the bending radii ρ, established by in-tube diagnostics and lying in the interval ρ_min≤ρ<1000D for each pipeline section separately.

EFFECT: technical result: simplification of the evaluating SSS in the identification of faulty welded joint in areas of elastic bending.

3 cl, 4 tbl