Abstract
Abstract. Operability of pipelines from combined pipes is determined on the one hand - by their design and materials used for their manufacture (combination of high chemical resistance of thermoplastic and strength of reinforcing elements), and on the other - by operating conditions: characteristics of transported medium, operating pressures, service quality, pipeline condition monitoring and repair and preventive measures. With regard to the medium to be transported, it should be noted that the most corrosive components include hydrogen sulfide and carbon slots, to which the low-pressure polyethylene of the posts. However, it is known that when the polymer and the medium to be transported interact, it is necessary to observe two mechanisms of exposure of polyethylene to the medium: chemical and physical. Mechanism of effect of oil-containing media on inner polyethylene shell of combined pipes is studied. It is shown that diffusion of oil and petroleum products into polyethylene leads to plasticization of the material and deterioration of its strength properties. Oil resistance of combined LPR and HPH pipes was experimentally investigated. Tests have shown that LPA-based pipes significantly reduce the strength properties in oil and therefore HPH (and other low molecular weight polymers) pipes cannot be recommended for transportation of oil-containing media. Comparative analysis of physical and mechanical properties of both individual materials and their compositions used in production of combined pipes was carried out. Shows the effect of dynamic loads on different composites. Preferred applications of metal-plastic and fiberglass pipes have been identified.