Evaluation of the residual life of a pipeline under conditions of erosion-corrosion wear

Abstract

The article is devoted to solving the problem of determining the residual resource of pipelines. Erosion and corrosion damage was selected as the main negative factor that is being investigat-ed and affects the service life. In particular, it is the erosion-corrosion damage of the “pitting corrosion” type which is one of the most serious and widespread types of corrosion that can cause a significant shortening of the service life of technical objects and an increase in the cost of their maintenance, repair, and replacement. The residual thickness of the pipeline wall was chosen as the defining parameter. In case there are no significant failure statistics, a probabilis-tic-physical approach is used to assess the objective technical condition and predict the residual resource of the specified structures. The approach to durability assessment is based on a proba-bilistic model and uses the DM failure distribution that is specially formalized on the basis of a Markov random process of the diffusion type with a constant rate. The DM distribution most accurately aligns statistical data on failures of mechanical objects, which are pipelines for vari-ous purposes. It is very valuable that the parameters of the used model are based on a physical interpretation, which allows for estimating the parameters of the model when there are no fail-ure statistics. The analysis is based on two key parameters: the average rate of change of the defining parameter change (the performance criterion) and the coefficient of variation of the generalized degradation process. The paper provides an example in which the residual resource of a pipeline section is determined with the help of the probabilistic-physical method. The re-sults obtained during the calculations are compared with the results obtained by another tradi-tional method. Refining the assessment of the residual resource of the pipeline section will al-low for optimizing the operating costs by reducing the intervals between repairs.