Development of a Methodology for Technical Diagnostics of Pipelines of the Gas Distribution System and Analysis of the Effectiveness of Ways to Restore their Operability

The main requirement for the functioning of a gas distribution system – starting from gas supply sources to end-users of gas – is to ensure its reliability, safety and operational efficiency while reducing the burden on the environment, from gas supply sources to end users of gas. At the same time, it is necessary to maintain all facilities of the gas distribution system in a technically sound condition, their constant updating and development. So, the aging and wear of the gas distribution system facilities in operation (gas distribution pipelines, gas control points, cabinet control points, electrochemical protection equipment for steel gas pipelines) is currently becoming an urgent problem. The article discusses the structure and growth dynamics of the length of steel underground gas pipelines operated in Minsk and the Minsk region, depending on the duration of operation. The results of laboratory studies of the actual state of steel pipes with different service lives are presented. The degree of degradation of the structure, mechanical properties and chemical composition of metal samples of steel underground gas pipelines with different service lives has been determined. The methods for assessing the actual state of the insulating coating of steel underground gas pipelines are presented. The analysis of the results of measurements of the electrical transient resistance of the insulating coating obtained in the field and laboratory conditions is carried out. The calculation of the residual life of an insulating protective coating is presented using the example of mastic bitumen insulation by determining the actual aging time constant, and a method for estimating changes in their activation energy of thermal and oxidative degradation as a method for determining the residual life of the insulating coating of steel underground gas pipelines is given, too. The values of the activation energy for mastic protective bitumen coatings of steel underground gas pipelines with different service life, including the limiting state, have been determined. A technique for technical diagnostics of steel underground gas pipelines is proposed, taking into account aggregated statistical data. A method for prioritizing gas distribution system facilities is described.