INFLUENCE OF BITUMEN-POLYMER AND ASMOL MASTIC COMPOSITIONS ON QUALITY INDICATORS OF MATERIALS FOR ANTI-CORROSION INSULATION OF OIL AND GAS PIPELINES

Underground pipelines operating experience shows that their operating life and reliability largely depend on effectiveness of metal corrosion protection, both internal and external surfaces. In the latter case, along with electrochemical protection, insulation coatings play an important role. In recent years, there has been a trend to use factory-insulated pipes. Its advantages are obvious: high-quality preparation of pipe surface, strict control over compliance with the technological mode of application. However, in some cases it is impossible to do without field coating: during overhaul, diagnostic works on the linear part and process pipelines of pumping stations. In this case, it is relevant the improvement of insulation materials and field coating technologies.The aim of this work was to study the influence of the component composition of bituminous-polymeric and asmolic mastics on their adhesion to the pipe metal and the operational characteristics of the insulating materials. In doing so, the following tasks were solved:A specially developed gravimetric technique to study the interaction of asmol with the metal surface was used. The cover films formed in this process were studied using an electron microscope at a 1000× magnification.It has been shown that when applying asmol coating, its functional groups enter into chemical interaction with the compounds formed on pipe surface. An indirect confirmation of this is an absolute resistance of the asmol coating to repeated flushing with solvents and water. This peculiarity is not observed in the case of bituminous-polymeric coatings: bituminous-polymeric mastic is completely washed off the surface of steel in a similar treatment.Calculating of the «reduced» cost of 1 km of pipeline re-insulation has revealed a significant advantage of asmol-mastic coating over the bituminous-polymeric one from the economic point of view, since the former not only provides a better adherence to the pipe surface, but also achieves significant savings, since a smaller thickness of the protective coating is required.