Rotating Equipment / Preliminary Screening Tool

Centrifugal Pump Selector

Specific speed classification, suction limit check, mechanical configuration, and preliminary power/curve estimate for centrifugal pump screening — single or multistage.
DOC PS-100 · REV A
UNITS US CUSTOMARY
00 System Settings
Nss is always computed and displayed in US customary units (industry convention), regardless of the unit system selected above.
01 Duty Point Input
Used for discharge pressure, API 610 screening limits, and flange rating.
Drives the applicable-standard and API 610 material class recommendations.
1.0 cSt ≈ water. HI viscosity correction is applied above ~4–5 cSt; negligible below that.
Above 200°C (392°F), a radially split casing is preferred over axially split — factored into the pump type suggestion below.
Sets the minimum NPSHR a pump must achieve to stay within a safe suction-limit range at this duty point. Always in US customary units (gpm, ft, rpm) per convention. Confirm against the vendor's actual NPSHR curve.
02 Screening Results
Specific speed classification — Ns (US units)
Affinity-law projection — variable speed (VFD)
Q₂
—
H₂
—
BHP₂
—
Q ∝ N, H ∝ N², BHP ∝ N³ — valid near the original best-efficiency point only; efficiency is held constant as an approximation.
03 Mechanical Configuration
Horizontal: OH1 below 200°F (93°C), else OH2. Vertical inline: OH3 up to 75 hp (56 kW), else falls back to horizontal.
Bearing selection — API 610 rolling-element limits
Leave blank to estimate from shaft torque. Enter the vendor's bearing bore to check an actual design.
04 Driver Selection & Rating
Non-motor drivers apply to horizontal-shaft pumps (OH1, OH2, OH6, BB) under API 610 or HI, and to NFPA 20 horizontal fire pumps.
Used to derate diesel engines and gas turbines.
05 Nozzle, Line & Flange Rating Estimate
Maximum velocity limits
Typical screening values for water-like liquids. Lower the suction line limit for hydrocarbons near their bubble point or for viscous service.
Flange pressure rating — ASME B16.5, based on max. discharge pressure
06 Applicable Standards
07 API 610 Material Classes
Summary of API 610 Annex H material classes (casing / impeller / shaft) and Annex G selection guidance. Wear rings, bolting, sleeves and other parts follow the full table. Shaded green: recommended; light green: alternatives; amber: your manual selection. Verify against the API 610 edition named in your project specification and against corrosion-engineering review.
08 Predicted Performance Curve
Schematic head-capacity & efficiency curve, shaped from the pump family above — illustrative only, not a certified vendor curve
09 Datasheet Export
Saves a self-contained HTML datasheet of the current inputs and results, including warnings and the performance curve. Open it in any browser and use Print → Save as PDF for a PDF copy.