“…In order to prevent a significant drop in the pre-treatment performance of the effluent in the proposed installation, the gratings should be cleaned at the time t = 0.5•t 1 . For reception of the graphical dependence of t I , S р.тах must be taken as a part of the cross-sectional area of the pipe -S p , which can be calculated, depending on the diameter D p : The flow rate Q c is determined based on the specified daily volume of wastewater at the enterprise Q Σ = 500 m 3 /day, the duration of shift T ds = 8 h, the coefficient k np that takes into consideration the duration of downtime due to the scheduled maintenance operations (cleaning, lubrication, adjustment, replacement and replenishment of working fluid in the hydraulic system, preventive testing of electrical and electronic parts of equipment, downtime for organizational and technical reasons (absence of worker, foreman, adjuster, work, raw materials, electricity, documentation, etc., as well as the coefficient variability of work k vw = 3 by the formula [Sevostianov 2019…”