An Approach to the Calculation of Pipe Friction Loss

This paper will discuss the method of calculating pipe losses based on the implicit solution. In the past, spreadsheet software, such as Microsoft Excel, has not been able to precisely calculate implicit formula due to its limitation in performing iterative calculations. Complex empirical equations have been approximated in the past to enable mass computation of the pipe frictional loss. Earlier version of Excel used explicit formula to compute an approximation of the implicit solution, however starting from its 2003 version, implicit formula are now able to be calculated en masse.

The main advantage of using the implicit solution over the approximations for the pipe loss calculation is that unlike the approximations, there are no constraints on pipe sizes and flow rates in the implicit formula.

This paper will compare results obtained using the implicit solutions and the approximations and discuss the implications of not selecting the correct approximation for the pipe size and flows tested in the design.