Quote Originally Posted by sick_g4m3r View Post
Because those figures will not be the same with the parts used
The DDC curve operates against some level of restriction. I factored the current 3/8" fittings on the pump into the system restriction curves. When I modelled the different fitting types, I can determine the impact in one of two ways:

1) Alter the pump's PQ curve based upon the fittings on it
2) Factor the fitting impact into the system's PQ curve, and intersect that with a constant pump PQ curve.

There may be very marginal variations between the two, but as I said, the nature of the shapes of the curves is such that any variations impacts everything roughly equally.

It's just easier to do #2.