Patent ID: 8398361

Claim:
A high-efficiency, multi-stage pump for pumping a fluid and being driven by a motor, the multi-stage pump comprising: three pump stages, each one of the three pump stages including a front casing, a back casing, an impeller, and a bladed diffuser, the impeller at least partially encircling the bladed diffuser; the front casing and the back casing being removably coupled around the impeller and the bladed diffuser to allow access to polish substantially entire inner surfaces of the front casing and the back casing when the front casing and the back casing are uncoupled from each other; the fluid being pumped through the three pump stages at a flow rate between about 300 liters per second and about 500 liters per second with an efficiency between about 86% and about 91% due at least in part to polishing substantially entire inner surfaces of the front casing and the back casing.