METHOD FOR IDENTIFYING POTENTIALLY DANGEROUS SECTIONS OF MAIN PIPELINES WITH COLD BENDS Russian patent published in 2023 - IPC F16L57/00 F16L57/02 

FIELD: oil industry.

SUBSTANCE: invention relates to the operation of main pipelines, in particular to the identification of potentially dangerous sections of pipelines with cold bends with an increased level of stress and strain state. A method is proposed for identifying potentially dangerous sections of main pipelines with cold bends, including determining the radii of curvature of cold bending bends based on the results of the penultimate and last in-line technical diagnostics on the section of the trunk pipeline, calculating changes in bending deformations in the wall of cold bends based on certain changes in the radii of curvature of cold bends and determining the magnitude of changes in bending stresses in the wall of the cold bends taking into account the variable modulus of elasticity. Comparison of the found value of the change in bending stresses in the wall of the outlet of cold bends with a limit value of 70% of the yield strength of pipe steel. If the found value of the change in bending stresses in the wall of the cold bending outlet of the above limit value, identification of the predisposition of the section of the main pipeline with the outlet of cold bends to the formation of transverse cracks.

EFFECT: determining the change in the level of the stress and strain state in the wall of cold bends based on the results of in-pipe technical diagnostics, taking into account the physical nonlinearity of pipe steel, in particular changes in the elastic modulus E.

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