Online Suction Specific Speed Calculator at Best Efficiency point .
Suction Specific Speed at BEP Formulas:
Imperial Units:
Ns = ( N * (Q)1/2 ) / (NPSH)3/4.
where:
Ns = specific speed.
N = pump speed, rpm.
Q = flow, gpm.
NPSH = net positive suction 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.
NPSH = net positive suction 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.