The paper presents a calculation model for assessing the wear resistance of radial plain bearings with a polymer coating and a groove, taking into account inertial effects and nonlinear properties of the medium under steady-state friction. Clarified analytical dependencies have been developed to improve the accuracy of calculations of the hydrodynamic characteristics of the bearing. The main objective of the study is to create a multifactorial model that takes into account the influence of the bearing geometric parameters (the presence and configuration of the groove), the properties of the polymer coating and the inertial force. The model allows predicting the bearing life in real operating conditions, taking into account the influence of various factors, which increases the accuracy of design and optimization of the design. The results of the work are aimed at improving the operational reliability of plain bearings due to more accurate prediction of their wear resistance and optimization of design parameters.

Keywords: modified design, nonlinear factors, polymer coating, axial groove, load capacity, friction coefficient, increased wear resistance

During the construction of water treatment stations in group water pipelines, it exceeds 15 ... 30% of the cost of the entire system and directly depends on the technological scheme, the choice of which, in turn, is influenced by the quality of the water in the source and the performance of the station. In large group water supply systems, water from surface sources is usually used, which must be clarified, discolored, deodorized, and disinfected.

Keywords: plumbing, reagent, turbidity, filtration flow, reliability, non-failure operation, sediment, technological schemes, investments, filter

This article presents the results of a research work devoted to the use of ultrafiltration membranes in the technology of purification of natural waters and wash waters of a contact clarifier unit, as well as design proposals developed on their basis for the reconstruction of existing water treatment plants.

Keywords: membrane technology, ultrafiltration, membrane module, natural water treatment technology, flushing water treatment technologywater treatment facilities, patent research

There were considered the processes of electrochemical coagulation and contact filtration for clarification, bleaching and disinfection of the Don River. There were made the experiments to compare electrochemical coagulation to chemical treatment of water with different reagents in conditions of contact filtration. There were defined feculence change, water chromaticity depending on reagent dose and the changе of the total microbial number.

Keywords: Extraordinary situations, water-supply, coagulation, clarification, bleaching, filtration, purification effect.