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[Mihai]

Kris, thanks for the input. How do I found out if I have a pressure rated or a flow rated pump? I have an ocean runner as return pump (from aquamedic).

M.

[kris4647]

I really know very little about Aquamedic pumps. With the impeller set-up like it is I would guess flow, but it could be a whole different ballgame with what I would call a "Power Head" type pump. [Nothing implied there, just how I know them.]

The flow curves in the manual say "flow" as well.

[I would like to make clear thats an educated guess and no more than that.]

[sawyerc]

Thanks for the update - that's interesting. It sounds like you know what you're talking about. If the pump does indeed throttle down, then you're right, teeing off just wastes energy. I'd be curious to know what pumps throttle down: all pumps, good pumps, powerheads...? Also, I realized that all of us have been saying "back pressure," but isn't backpressure when the intake of the pump is restricted as opposed to head pressure which is at the output?

[kris4647]

Keep forgetting the notify button


I think back pressure is a relatively generalized term. In our industry[normally] back pressure is held on many process systems based on the spill back system we discussed earlier [Discharge output -->Suction input]. I have heard the term, especially in the hobby, in reference to what I would call head pressure. That is pressure on the discharge side of a pump.

It must be noted that pumps have suction head pressure NPSH
[Net Positive Suction Head] as well. And it gets more complicated from there [A chemical/mechanical engineer could probably help out with some more terminology if you are interested]

As for what pumps respond in this manner I can really only speak for centrigugal external pumps, although I'm guessing submerged pumps work in the manner, I cant be sure.............