The paper presents a design procedure improved by using power law friction factor, which provides accurate solutions for three types of pipe design problems (Types A, B and C) with considering effect of local losses. The parameters introduced in the power law are related with the type and size of commercial pipes, thus several dimensionless physical numbers by a suitable combination of the variables for the solution of Type B and Type C problems, are also introduced. For solution of the general case of a Type B problem (sloping pipe with pumping power), user-friendly the MathCAD procedure, which produces a consistent framework for analyzing and solving common piping-system applications, was also carried out. In order to prove degree of accuracy of the present technique, several design examples are examined for three types of commercial pipes, and for a wide range of uniform pipe slope, and the results are shown in the design curves. The curves employed have practical importance to quickly determine the values of required variables for a given pipe slope. Moreover, they also give an opportunity to compare the results of the proposed method with those of obtained from the recent study. The comprehensive comparison test clearly indicates that, the proposed technique yields an exact design solution, thus can eliminate severe errors originated from the existent literature, in profession practice.