POLYETHYLENE GAS PIPELINES: PRACTICAL POSSIBILITIES TECHNICAL DIAGNOSTICS

Technical diagnostics of in-service polyethylene-exhaust gas pipelines face a number of difficulties, since the existing methods of destructive control are not applicable for determining the mechanical and physical characteristics-stick of polyethylene pipes. The search for effective control methods that can most fully characterize the quality of pipe material and the interpretation of the results obtained are of scientific and practical interest. The article on the example of technical diagnostics of the polyethylene gas pipeline built in 1985 considers possible criteria for assessing the condition of pipes and their ranking by significance. It was found that polyethylene pipes produced during the development of their production did not always meet mandatory quality requirements and could have hidden defects in the form of inhomogeneities, cavities and cracks throughout the volume of pipe material. Based on the experimental studies carried out, it was shown that the pipe material during underground operation does not undergo significant changes in its initial characteristics. At the same time, it was noted that the pipe grades of polyethylene raw materials of the first generation had low resistance to slow crack growth, therefore, the presence of internal defects in the pipe material in owning value with the effect of concentrated loads can lead to premature loss of containment. The work carried out confirmed the possibility of a quantitative design assessment of the technical condition of the gas pipeline based on the results of destructive tests of pipes for long-term hydrostatic strength. The experimental data presented in the article are of interest to specialists who are faced with the need for expert assessment of the state of the pipes of the operated polyethylene gas wires and forecasting their service life.