Ismailov, M. UDC 621.565.93/95 INFLUENCE OF SURFACE LAYER THICKNESS ON HYDRAULIC RESISTANCE OF THE DEVICE : Purpose of the Work: The Increase in the Thickness of the Scale on the Inner Surfaces of Technological Pipes Reduces the Cross-Sectional Area of the Pipe, Thereby Decreasing Its Conductivity. As a Result, the Coefficient of Friction in the Pipe Increases, Which in Turn Leads to an Increase in Its Hydraulic Resistance. This Causes a Sharp Increase in the Amount of Energy Consumed, As the Required Pump Power for Fluid Transportation Rises Accordingly. STJ NamIET 2024, 9, 137-141.