While we have a decent discussion about pumps going....
Does anyone know what makes a pump have a high head (read: pressure) rating? How about a high flow rating? What produces more pressure, closed or open impeller? What produces a larger flow rate, a close or open impeller? What type of an impeller do most our pumps use (MCP600,650,350, eheims, mags, iwakis)? Do certain structural limitations exist when using a closed impeller? What is the benefit to using an open impeller? I feel that this would be good general information for the community to have.
I would tend to say that a closed impeller is more efficient overall. It would be the equivalent of having two open impellers facing each other (a rough analysis). Open impeller pumps can be smaller, are easier to manufacture, and are much easier to design as a mag drive (to the best of my knowledge). Most of the pumps that we use are open impellers with the exception of iwakis which are closed. I honestly don't know about the MCP 650. Anyone else want to chime in?
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