"Multiplicity ought not to be posited without necessity."
— Occam's Razor
Closer to Best Efficiency
Recommended pump minimum flow is usually designated as a percent of
BEP (best efficiency point) flow, the percentage being determined by impeller
design and diameter, suction specific speed, and the combination of capacity,
head and horsepower.
The Split Flow solution
Use of the Split Flow feature with process pumps allows the specified operating range to be closer to BEP, as recommended by the API Standard 610 hydraulic fit criteria. This optimized pump-to-system fit reduces the pump's minimum flow and simplifies turndown control.
Click to see: Performance curves comparing a 100 hp Hexene Reflux / Purge pump with a 50 hp Split Flow-fitted pump for the same service conditions. The conventional 100 hp pump requires 250 gpm minimum flow - the 50 hp Split Flow-fitted pump requires 150 gpm minimum flow.
The smaller motor enables a savings of approximately $11,400 per year based on $0.035 per kWh.
Centrifugal Pump Operation at Off-Design Conditions
By Igor Karassik
By Bill Murray in Pumps and Systems Magazine