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Pump Sizing Calculator

Choose your calculation mode based on available information

🎯 Pump Sizing & Selection
Choose your calculation mode below based on available information. Implements API 610/674 standards with NPSH analysis per ANSI/HI 9.6.1-2017.
Calculation Mode:

Analysis Capabilities

System Modeling:
Account for Pipe Length, Fittings (Elbows, Tees, Valves), Elevation Changes (Static Head), and Tank Pressures.
Pressure & Loss:
Total Dynamic Head (TDH), Darcy-Weisbach Friction Loss, Pressure Drop analysis, and System Head Analysis.
Performance Outputs:
Brake Horsepower (BHP), Hydraulic Power (WHP), NPSHa (Available), NPSHr (Required), Motor Sizing (API 610/NEMA).

📘 Mode Selection Guide

Choose the right mode for your situation:

🔧 Simple Pipeline Mode
  • Starting from scratch with basic pipeline info
  • Need automatic friction loss calculations
  • Calculates: Friction, head, motor size, NPSH
📊 System Analysis Mode
  • You have measured system pressures
  • Head losses already calculated
  • Replacing existing pump
⚡ Quick Estimate Mode
  • Need ballpark numbers for budgeting
  • Preliminary feasibility study
  • Fast estimate with minimal inputs

Core Formulas

Water Horsepower:

WHP = (Q × H × SG) / 3960

Brake Horsepower:

BHP = WHP / ηpump

Required Motor HP:

Motor HP = (BHP × SF) / (ηmotor × 1.15)

Specific Speed:

Ns = (N × √Q) / H0.75

Standards Reference

  • API 610: Centrifugal pumps for petroleum
  • API 674: Positive displacement pumps
  • ANSI/HI 9.6.1-2017: NPSH margin
  • NEMA MG-1: Motor standards
  • Darcy-Weisbach: Friction loss equation

Frequently Asked Questions

How is pump brake horsepower (BHP) calculated?

Brake Horsepower (BHP) is calculated by dividing the Hydraulic (Water) Horsepower by the pump efficiency. Formula: BHP = (Q × H × SG) / (3960 × η), where Q is flow in GPM, H is head in feet, SG is specific gravity, and η is efficiency.

What is the difference between NPSHa and NPSHr?

NPSHa (Available) is the absolute pressure at the pump suction minus vapor pressure, determined by the system design. NPSHr (Required) is the minimum pressure required by the pump to prevent cavitation, determined by the manufacturer. For safe operation, NPSHa must exceed NPSHr.

How do you calculate pump total dynamic head (TDH)?

Total Dynamic Head (TDH) is the total equivalent height that a fluid is to be pumped, taking into account friction losses in the pipe. TDH = Static Head + Friction Head + Pressure Head.