Ismailov, M. 2024. 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. Scientific and Technical Journal of Namangan Institute of Engineering and Technology. 9, 4 (Dec. 2024), 137–141. DOI:https://doi.org/10.61151/stjniet.v9i4.624.