Pumps
NPSHa vs NPSHr Check
NPSHa screening with >= 1 m margin rule.
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Pumps calculators
Pump power, affinity-law, and NPSH margin calculators for centrifugal screening. Enter flow, total head, efficiency, speed change, suction head, and vapor pressure to estimate shaft power, BEP shift, available NPSH, and parallel or series combinations. Results show the power and NPSH equations step by step, with guides for cavitation avoidance and field verification.
Pumps
Pump Affinity Laws
Affinity laws: Q2=Q1(N2/N1), H2=H1(N2/N1)^2, P2=P1(N2/N1)^3.
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Pump Duty Point Solver
Pump-system curve intersection, closed form.
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Pump Head and Power
Hydraulic power Ph = rho*Q*H/366972. Shaft = Ph/eff. Motor with 15% margin.
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Pump Parallel / Series Compare
Parallel Q adds at same H; series H adds at same Q. Screening before curve intersection.
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Pump Specific Speed
Specific speed Ns = n sqrt(Q) / H^0.75 (Q m3/s, H m/stage). Radial < 40, mixed 40-80, axial > 80.
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Suction Energy Screen
Suction-energy screening index = De x n x Q_BEP / 1e6. High values need API 610 review.
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Total Dynamic Head (TDH)
Static plus friction, minor and pressure head.
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VFD Energy Savings & Payback
Affinity-law savings with payback years.
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