The article compares linear hydraulic losses calculated from Colebrook-White, Prandtl-Karman and Blasius formulas with the measured on a test pressure in pipelines with the diameter of 63, 75 and 90 mm, made of PVC and PE. The pipelines were arranged in loops through which flew sewage with the suspension contents of about 460mg/dm3. As a result of the tests it was established that the accuracy of the Colebrook-White formula is higher than that of Prandtl-Karman and Blasius formulas (the only exception being the diameter of PVC63). However, it does not reflect properly the character of changes of linear pressure losses that accompany the increase of the speed. This character is better reflected by formulas for hydraulically smooth pipes, particularly by the Prandtl-Karman formula. Differences between values measured and calculated for the tested scope of diameters and speeds do not exceed 10%. In most cases, however, the calculated values are smaller than the measured ones.
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