Pipes Relative Capacities

Overview

Engineering reference data for Pipes Relative Capacities in piping systems.

Key Formulas

Continuity

$A_1 v_1 = A_2 v_2$

Mass conservation in pipe flow.

Pressure Drop

$\Delta P = f \frac{L}{D} \frac{\rho v^2}{2}$

Darcy-Weisbach equation.

Pipe Area

$A = \frac{\pi D^2}{4}$

Cross-sectional area of a pipe.

Variables

Symbol	Description	Unit
$D$	Pipe diameter	m
$v$	Flow velocity	m/s
$\Delta P$	Pressure drop	Pa
$f$	Friction factor	—

Pipe Inside Dimensions

Relative Capacity Table

The relative capacity indicates how many smaller pipes are needed to match the flow capacity of one larger pipe, based on cross-sectional area ratios.

Application Notes

• System sizing: Use relative capacity when converting between pipe sizes in a distribution network
• Parallel piping: Multiple smaller pipes can replace a single larger pipe when capacity ratios match
• Flow assumption: Relative capacity based on area ratio assumes equal flow velocity across all pipe sizes

Interactive Charts

References

• Original Source