Water supply networks. The practice of accounting for local pressure losses
Local pressure losses are caused by resistances in the armature, fittings and equipment, due to the narrowing and widening of the flow, changes in the flow direction, merging and separation of the flow, changes in the shape and size of the channel, etc. Analysis of various methods for calculating the coefficients of local resistance of pipelines in designing a circular pressure network of water supply is of practical interest from the point of view of energy costs when moving the liquid. Literary sources contain various formulas and tables for determining the coefficients of local resistances. However, the values found from these data give rather large discrepancies, even for simple cases of local resistances (retraction, rotation). In this regard, we have to state that the most reliable way to determine the coefficients of local pressure losses is the experiment.