Yuzevych L. Improvement of normative providing of underground gas pipelines quality

The thesis is devoted to research of information that is used for formulation of recommendations of making decision in relation to the evaluation of quality and longevity of underground metallic gas pipelines in the conditions of corrosive fatigue. The features of early exposure of crisis (pre-emergency) situations are set. A complex qualimetric criterion for determination of level of quality of pipeline taking into account cathode defence and other aspects of technological specific is presented. The energetic criterion of fracture mechanics according to that there is an act of fracture in the arbitrary elementary volume of material is fixed in basis of model of corrosive fatigues of metal, if plastic deformation total energy for all cycles of loading will attain a critical value, what equal to fracture energy. Criterion correlation in relation to determination of speed of remaining corrosion of metal in the defect of isolating coverage for control of corrosive process taking into account polarization potential used. This correlation is set forth for the top of crack that is an anodic area. In zones with non-stationary plastic deformations the criteria of adhesion strength, biologically corrosivity of soils, mechanical criterionfor the coefficient of intensity of tensions, criterion of inoxidizability of defect, are used, criterion correlation for the estimation of speed of remaining corrosion of metal in the defect of isolating coverage. These criteria complement the system of the corrosive monitoring of pipelines, specify and perfect. They are use ful to control and optimization of corrosive process, and also for development of recommendations of relatively anticorrosive defence of metal. The project of standard "Electrochemical corrosion protection linear part of underground metallic gas pipelines taking into account fatigue life" was developed.