Mark,
I just took a full set of measurements on my Pentair IntelliFlo with my system in various configurations and list this below. Unfortunately, I had done a detailed list of pipe lengths, number of elbows, etc. but that all got stolen with my laptop a while ago so I'll have to reproduce all of that at some time in the future. Nevertheless, I've given some rough estimates to this below.
SOLAR ON. This has a very long pipe configuration as it must go a hundred or so feet from the pump house to the house, then down the full length of the house through 12 parallel solar panels and back again. The pipes are all 2" for this part of the system. Then, going to the pool starts out as 2" then splits into three 1.5" pipes -- one for each return. The suction side has two 1.5" pipes, one for the one skimmer and the other for two floor drains. The PSI below are pressure-side only, from my filter gauge.
[EDIT] I'm adding the implied overall pump efficiency based on GPM * PSI * 0.4347, but actual efficiency is higher since I'm ignoring suction head. [END-EDIT]
30 GPM, 2300 RPM, 715 W, 14 PSI, 25.5%
33 GPM, 2370 RPM, 785 W, 15 PSI, 27.4%
36 GPM, 2490 RPM, 895 W, 16 PSI, 28.0%
39 GPM, 2630 RPM, 1045 W, 18 PSI, 29.2%
42 GPM, 2755 RPM, 1185 W, 20 PSI, 30.8%
45 GPM, 2900 RPM, 1380 W, 22 PSI, 31.2%
48 GPM, 3000 RPM, 1530 W, 24 PSI, 32.7% <--- this is what I normally run at when the solar is on (this is 4 GPM per panel)
51 GPM, 3200 RPM, 1835 W, 27 PSI, 32.6%
54 GPM, 3325 RPM, 2075 W, 29.5 PSI, 33.3%
57 GPM, 3425 RPM, 2295 W, 31 PSI, 33.5% <--- this is close to the 3450 RPM maximum of the pump
With my SOLAR OFF, I just have the runs to/from the pool that I described above and I get the following.
15 GPM, 1185 RPM, 155 W, 3 PSI, 12.6%
18 GPM, 1325 RPM, 195 W, 4 PSI, 16.1%
24 GPM, 1460 RPM, 255 W, 4 PSI, 16.4% <--- I run close to this at 26 GPM when the solar is off
30 GPM, 1805 RPM, 420 W, 6.5 PSI, 20.2%
36 GPM, 1975 RPM, 535 W, 8 PSI, 23.4%
42 GPM, 2160 RPM, 685 W, 9.5 PSI, 25.3%
48 GPM, 2310 RPM, 835 W, 10.5 PSI, 26.2%
54 GPM, 2490 RPM, 1030 W, 12 PSI, 27.3%
60 GPM, 2710 RPM, 1305 W, 14.5 PSI, 29.0%
66 GPM, 2900 RPM, 1590 W, 17 PSI, 30.7%
72 GPM, 3080 RPM, 1895 W, 19 PSI, 31.4%
78 GPM, 3360 RPM, 2495 W, 22.5 PSI, 30.6%
I have ThePoolCleaner on a dedicated 1.5" line that I switch to for cleaning off-hours. When I disconnect the cleaner, then I get the following which shows the flow resistance solely from the 1.5" line and an outlet that has an adapter from 1.5" to 2" (since ThePoolCleaner is 2").
15 GPM, 1370 RPM, 200 W, 4 PSI, 13.0%
18 GPM, 1475 RPM, 245 W, 4.5 PSI, 14.4%
21 GPM, 1610 RPM, 300 W, 6.5 PSI, 19.8%
24 GPM, 1850 RPM, 420 W, 8 PSI, 19.9%
When I connect ThePoolCleaner it adds resistance and I get the following.
15 GPM, 1955 RPM, 425 W, 10.5 PSI, 16.1%
This may not have been the final stable cleaner number since it seems to be at 2180 RPM, 540 W at other times I've measured it (so probably a higher pressure as well). At any rate, it shows that ThePoolCleaner adds about 7 PSI to pressure resistance at the 15 GPM flow rate. This flow rate, which is the lowest I can set with the Pentair Intelliflow, produces a little over a 14 wheel RPM on ThePoolCleaner which is at the high-end of its recommended 11-14 wheel RPM range, but I don't find the pressure relief valve getting triggered so it's probably still OK.
The above all implies certain equivalent pipe lengths, but I'll have to see how that matches with actual lengths later when I get a chance.
Richard