A Calculation Method for Residual Strength and Remaining Life of Pipes in Pipe Gallery

Abstract

The invention discloses a residual intensity and residual life computing method for pipe gallery pipelines. The residual intensity and residual life computing method comprises the following steps: collecting the data information of defects of the pipe gallery pipelines; judging the defects are plane type defects or volume type defects; for the plane type defects, obtaining the engineering stress-strain curve of a defect pipeline material from the data information of the defects of the pipe gallery pipelines, determining a failure assessment diagram, and then computing assessment points to obtain the residual intensity of the pipe gallery pipelines; for the volume type defects, obtaining the design factors, the weld joint factors and the minimum measurement wall thickness from the data information of the defects of the pipe gallery pipelines, and obtaining the residual intensity of the pipe gallery pipelines through computing; computing basic numerical values according to the data information of the defects of the pipe gallery pipelines, and computing the residual lives of the pipe gallery pipelines according to a maximum value distribution probability density function, a reliability function, maximum corrosion depth point estimation and maximum likelihood estimation. Therefore, the residual intensity and residual lives of the pipelines in a pipe gallery area are effectively and accurately computed and predicted.

Description

technical field [0001] The invention relates to the field of pipes in a pipe gallery, in particular to a method for calculating the remaining strength and life of a pipe in a pipe gallery. Background technique [0002] The types of pipeline defects in pipe gallery are divided into planar defects and volume defects according to their geometric shapes. Predicting and calculating the remaining strength and life of the pipelines in service, and obtaining relevant information about the pipelines in advance can effectively reduce the incidence of accidents and ensure the safe and efficient operation of pipelines. [0003] At present, the methods and standards used to calculate the residual strength of defective pipelines are different at home and abroad. [0004] The main foreign residual strength standard: ASME B31G "Residual Strength of Corroded Pipeline Manual" (American Society of Mechanical Engineers), based on the elastic-plastic fracture mechanics of medium and low strengt...

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Problems solved by technology

[0005] The main domestic residual strength standard: SY / T 6477-2000 "Evaluation Method for Residual Strength of Oil and Gas Transmission Pipelines Containing Defects Part 1: Volumetric Defects", applicable to pipeline materials that are ductile and will not become embrittled during operation, and pipelines Crack-type defects are not included; SY / T 0087.1-2006 "Steel Pipeline and Storage Tank Corrosion Evaluation Standard for Direct Evaluation of Buried Steel Pipeline External Corrosion" is only applicable to volume-type corrosion defects, not crack-type defects

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