Online Pump Specific Speed Calculator at Best Efficiency point .
Pump Specific Speed at Best Efficiency Point Formulas:
Imperial Units:
Ns = ( N * (Q)1/2 ) / (H)3/4.
where:
Ns = specific speed.
N = pump speed, rpm.
Q = flow, gpm.
H = head, ft.
Values are taken at best efficiency point (BEP). Pump flow is taken at the largest impeller diameter For double suction impellers pump flow is divided by two.
SI Units:
Ns = ( N * (Q)1/2 ) / (H)3/4.
where:
Ns = specific speed.
N = pump speed, rpm.
Q = flow, m3/h.
H = head, m.
Values are taken at best efficiency point (BEP). Pump flow is taken at the largest impeller diameter For double suction impellers pump flow is divided by two.