Iso efficiency curves

I am looking for any code or an guidance, regarding how to draw pump iso efficiency curves in excel or any program in C or JAVA.... please help...

For most pumps the efficiency curves are empirically estimated from various pump tests at various pressure heads. So I doubt there is one generic formula that covers all pumps. I suspect each manufacturer will have their own set of curves.

That said there must be some general curves for each of the main pump types.

Yes, very true. But my requirement is how can I draw ISO efficiency curve pragmatically when I am having Flow head and respective power values? Can you help on this?

There is a certain amount on the web, i.e. http://www.idc-online.com/pdf/papers/bernard_dacruz.pdf that explains how to make the ISO efficiency curves. Though you really need to buy the ISO documentation on this: http://www.iso.org/iso/catalogue_detail.htm?csnumber=41202

Regarding making a program to produce this graph, then if you have the data then most of the lines can be easily plotted on. The challenge is producing the contours of efficiency; which by all accounts seem to be hand drawn / estimates for most pump graphs I've seen. There are plenty of contouring routines, so its certainly very possible, but its really a question of how many of these are you aiming to produce. Sometime some final editing with photoshop is quicker!

Thank you very for the reply. I really appreciate the solution and will try to materialize the same and will let you know..