On special features of determining the coefficient
of equivalent polymer pipe roughness
(to be discussed)

Summary

The criteria of estimating the condition of the inner surface of water and wastewater pipelines are considered and appraised. In particular, the feasibility of using equivalent roughness Кэ coefficient as such a criterion is substantiated. Two main methods of determining Кэ parameter are presented and described: with the help of hydraulic experiments with subsequent processing of the results by Prandtl and Colebrook–White equations; direct measurement by a proficorder of the arithmetic mean deviation of the profile of the inner surface of the pipe from the midline Ra with the subsequent conversion to Кэ using the empirical dependence obtained by A. Ia. Dobromyslov. An assessment of the reliability of the results obtained by these methods is given. The feasibility of developing a standard regulating the procedure of determining the parameter Кэ and the mandatory in-process monitoring of it are considered.

Key words

hydraulic design , water and wastewater systems , polymer pipes , coefficient of pipe inner surface roughness