A method for estimating the metal residual life of the weld pipes of gas main pipelines

Abstract

A method was proposed for estimating residual life T res with the use of the plastic strain ɛop accumulated by the metal of a pipe during its operation, the minimum critical plastic strain increment Δɛcr, upon whose accumulation during further after-inspection operation a mechanical property attains its maximally allowable regulatory value, and the known operating time T op of an inspected gas pipeline section. The method makes it possible to increase the reliability of the estimation of the metal residual life of inspected pipes and to exclude the factor of randomness due to the fact that the strain ɛop accumulated by the metal of a pipe and the minimum plastic strain increment Δɛcr are determined on specimens that are cut from an inspected pipe instead of those cut from an emergency stock pipe or from a thermally treated inspected pipe.