Centrifugal Pumps - Capacity Modulation
Calculate and compare pump capacity modulation methods including speed variation and constant speed regulation. Estimate changes in power consumption, head, and volume rate using affinity laws.
Capacity Modulation Methods
Centrifugal pump capacity can be regulated at:
Variable Speed (Energy Efficient)
- Hydraulic/hydrostatic drives
- Mechanical drives (belt and sheave)
- Eddy current drive/clutch
- Variable speed drives (inverters/AC drives)
Constant Speed (Less Efficient)
- Throttling (discharge valve)
- Bypassing flow
- Changing impeller diameter
- Modifying impeller blade pitch
Calculations use affinity laws to estimate changes in power consumption, head, and volume rate.