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The theory and practice in engineering industry is not the same. Durability of cutting tools is defined in standard ISO 3685. In standard ISO 3685 is defined T-vc dependence for different cutting materials and standard included process evaluation of tool durability for cutting materials made of high speed steel, sintered carbide and cutting ceramic. Standard ISO 3685 contains instructions how to create T-vc dependence for cutting tools made of cutting ceramic. In this standard are only instructions how to create T-vc dependence according to Taylor. The article compares T-vc dependencies for various cutting ceramics (Al2O3, Al2O3+ZrO2, Al2O3+TiCN) with T-vc dependence defined in standard ISO 3685, because this standard describes T-vc dependence for all entered cutting materials together.

Abstract

This paper focused on axial flow pump high operation, reliability, and long service life at different frequency of rotation (DFR). The efficiency of an axial pump varies considerably depending upon the conditions under which it must operate. This article concentrates methods related to the reliability analysis of pumping system operation by a frequency converter. Initially, it is focused to analyze the behavior of individual characteristic curves of the axial pump to find how can be applied for the determination of the most efficient frequency of rotation. Axial flow pumps are often controlled by adjusting their rotational speed, which affects the resulting flow rate and output pressure of the pumped fluid. In addition, the head and flow of fluid transported at different frequencies of rotation, to produce a map of reliability characteristic curves to verify the similarity rules for pumps recommendable operating region are discussed. The results showed that the recommendable operating region for a different revolution per minute of axial pump can be determined with efficiency. If the axial flow pump is driven outside its operating region, the efficiency decreases, and the reliability and long service life may be affected.