There are lots of pump curves published by pump manufacturers.
What exactly do
they (the pump mfgrs) do to get these curves?
Bill - maybe you could call the manufacturer of the Swiftech pump and ask
them for some guidance? It's a good pump and any kind of fair measurement between pumps is (IMHO) going to show it off very well, so hopefully they won't feel any urges towards obsfucation.
There might even turn out to be different "standard" ways to define water column height, which might explain some of the discrepancies we see.
I've just gone looking across pump manufacturer/distributor web sites, and ran across some (IMHO) very good tech intros at
Goulds Pumps - particularly
Introduction to Pumps Reading Curves (IMHO+BTW appropriate for the ProCooling "links" section). There's mention in there of a
Hydraulic Institute - and it looks as though
they are working on some pump output measurement standards (looks a lot like ANSI - in that you don't get to look at the standards unless your organization "joins"). Maybe the manufacturer Swiftech is dealing with is already a member(?) Think it's worth asking?
Bob