Are pressure/flow curves for either Intex (http://www.intexcorp.com/support/28603eg.html) or Bestway (http://www.bestway-northamerica.com/product_page?product_id=1360) pumps available? Support at each of those companies said no, though I think if I spoke to an engineer they would give me another answer.

On another note, I see many pressure/flow curves that extend to zero flow - Waterway's (http://waterwayplastics.com/products/pool-products/pumps/above-ground/hi-flo-2-side-discharge-48-frame/) curves for example. Most full size pool pumps have flow rates above 50 gpm. What will happen if I run a pump at low flow, e.g. 3 gpm, by restricting the outlet? This is equivalent to raising the water, as far as the pump is concerned. Will this burn out the pump? If so, then why do the manufacturers show curves extending to zero flow? If not, then why do the pumps technicians tell me (when I call them) that it will?

Does this help you http://www.documentation.emersonprocess.com/groups/public/documents/bulletins/debul2007x012.pdf

Wow, yes, for my second question group it does. Very interesting. I'll have to read it more in depth.

I see now that what I thought would be the interesting part, Flow Chart 2, is for gases; so it brings no enlightenment.