Pump Performance Curves

Overview

This skill provides comprehensive methods for generating, interpreting, and manipulating pump performance curves. Performance curves are fundamental to pump selection, system design, and operational analysis. The skill covers the four primary curve types (H-Q, η-Q, P-Q, and NPSH-Q), affinity laws for scaling performance, curve fitting techniques, and operating point determination.

Performance Curve Components

1. Head-Flow (H-Q) Curve

The H-Q curve shows the relationship between total dynamic head and volumetric flow rate.

Characteristics:

• Shutoff Head (H₀): Head at zero flow (Q = 0)
• Design Point: Nominal operating condition (Q_design, H_design)
• Runout Flow: Maximum flow at zero head
• Curve Shape: Typically descending, influenced by impeller design

Mathematical Representation: