Do we know the attainable efficiency of centrifugal pumps better?

Many factors affect the efficiency of centrifugal pumps and several studies from the 1940s on have attempted to document these. In this first Special Focus article S.L. Abhyankar of the Indian Pump Manufacturers Association provides a guide to the approaches taken by these seminal studies, and shows how regressional analysis can simplify the process of calculation. We follow this with a brief overview of India's pump industry and then take a look at one of the country's major manufacturers.