HI 20.3 presents a simplified method to predict normally attainable efficiency levels at the best efficiency point for selected types of rotodynamic pumps when the rate of flow, total head per stage, net positive suction head available (NPSHA), and the service conditions are known. The standard provides guidelines on the following pump types:

• Slurry, end suction
• Solids-handling, end suction pumps
• Submersible sewage, end suction
• Paper stock, end suction
• Horizontal multistage, axial split, segmented ring diffuser barrel
• ASME B73, API end suction, end suction - small
• End suction - large (greater than 0.3 m3/s [5000 gpm]) - Does not include sealless, self priming, or pumps included above
• API double suction
• Double suction, general service
• Vertical turbine, mixed-flow and propeller, single and multistage diffuser type