Hey. At the moment, for my fluid mechanics course, i am working on an assignment where i have been instructed to design a basic fluid system which involves the use of an operating centrifugal pump. The system i have chosen is a pool circulation and filtration system. I have finished with most of the system design work and calculations involving head requirements, NPSH available etc., however i now need to select a pump which would be suitable for the job. I have searched through the websites of quite a few pool pump manufacturers, and what i have found is that most of them have published a "head supplied vs. flow rate" curve, but none of them provide NPSH or efficiency curves. Does anybody know why NPSH curves are not published for smaller scale pumps like these? If i can't get hold of any, are there any rough guidelines that i should follow when sizing a pump to ensure that cavitation does not occur, and that the pump isnt operating too inefficiently? Clearly i am a beginner to this, so any help is very much appreciated Thanks, Dan.