Evaluation of residual operating life of pipeline based on metal strain ageing

The remaining life of main pipelines is defined by three factors: mechanical behavior of pipe metal, defect rate, and the state of the insulating coating. The evaluation of the remaining life of pipe metal in the context of the aging effect presents a great problem. The issue is the absence of data stores of original mechanical properties of pipes forming a pipeline. This problem can be resolved on the basis of the known conditions: the variation dynamics of the coercive force is closely related to the variation dynamics of mechanical properties; during heat treatment of metal its coercive force recovers to the initial condition. We discuss an example from the practical experience of operation of the Bukhara–Ural gas pipeline.