At present, the domestic product samples "220V Cooling Fan" centrifugal fan, have adopted the non-dimensional performance curve shows a similar model series fans (different machine number) in common. Dimensionless performance curve is not only to reduce the number of "220V Cooling Fan" fan performance diagrams to simplify the representation, but also to facilitate the different characteristics of the various series fans compare and selection. Non-dimensional performance parameters and dimensionless performance curves, in theory also applies to the pump, but due to the type "220V Cooling Fan" pump range, pump cavitation problems still exist in itself, so the pump does not use non-dimensional performance curve.