To determine the pressure loss of liquids in pipelines during the transition from laminar to turbulent motion several dependencies for the coefficient of hydraulic friction are found. They are the dependencies of the ratio from the Re number of and can be obtained in the form of a segment of a series from three or four terms. The implementation of the process can be performed either by using elementary computational devices, and using the computer program. Upper and lower Reynolds numbers are set arbitrarily, taking into account the working conditions of the pipeline. Method was experimentally confirmed. The results could be applied in the design of construction machinery and equipment of average power operating at high frequency vibrations. Dependences for the coefficient of hydraulic friction are applied for the calculations of pipelines for liquid mixes.