Mastering Pump Sizing

 Mastering Pump Sizing

Mastering Pump Sizing: 

1 Calculate the Flow Rate (Q):

Determine required flow (L/s or GPM) based on system demand - chilled water, potable water, or fire suppression.

2 Estimate the Friction Loss (Pf):

Use Hazen-Williams or Darcy-Weisbach to calculate pressure loss through piping, valves, and fittings. Example: A 2" pipe over 100m with multiple bends might lose ~15 kPa.

3 Account for Static Head (Hs):

This is the vertical lift the pump must overcome especially vital in booster and drainage systems.

4 Determine Residual Pressure Requirements (Pr):

Ensure minimum pressure at the most remote fixture e.g., 1.5 bar at a hose reel or terminal unit.

5 Apply a Safety Factor:

Add 10-15% to account for system aging, future expansions, or estimation uncertainty.

6 Define Flow Type: Fixed vs. Variable:

Fixed Flow: Use constant-speed pumps (e.g., tank transfer)