This section outlines the rules that Skelebrator uses for creating equivalent pipes from parallel or series pipes.

These equations can be solved for equivalent diameter or roughness (C, n or k). With the Darcy-Weisbach equation, the equations are solved only for D because there are situations where the roughness can be negative. Both solutions are presented. In general, there will be one pipe that is the dominant pipe, and the properties of that pipe will be used when a decision must be made. There will be some default rule for picking the dominant pipe, but you will be able to override it.

You will not use equivalent lengths because you want to preserve the system geometry. For pipes in parallel, you will use the length of the dominant pipe while for pipes in series, you will add the lengths of the two pipes as follows:

Lr = L1 + L2