A Pump is direct driven by a 25 HP 900 rpm electric motor at rated load. In order to to double the quanitity of water delivered, it would be necessary to substitute a motor rated at____HP at____rpm. ans. 200 and 1800. not sure how they came up with this answer...whats the equation???
N = (95 H.C)/D Where N = rev/min D = diameter of impeller over blade tips in metres H = total head in metres C = constant. C depends on the shape of the pump and normally lies between 1.05 and 1.2 Later edit. I'm not sure if you are aware of it but each impeller has it's own characteristic performance curve.
