Low Pressure Gas Piping

Overview

Engineering reference data for Low Pressure Gas Piping 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	—

Low Pressure Gas Pipe Sizing Tables

The following tables provide recommended nominal pipe sizes for low-pressure gas service lines serving multiple apartments. These tables account for diversity in consumption across multiple consumers.

Pipe Sizing: 20–110 ft Service Lengths

Pipe Sizing: 120–200 ft Service Lengths

Design Conditions

These sizing tables are based on the following assumptions:

Parameter	Value
Pipe type	Schedule 40 steel pipe
System pressure	Low pressure service line
Pressure head	6 inH₂O
Gas specific gravity	0.6
Allowable pressure drop	0.3 inH₂O

Note: The pipe sizes account for diversity in consumption when multiple consumers are supplied from a single service pipe. As the number of apartments increases, the probability that all consumers use gas simultaneously decreases, allowing for smaller pipe sizes relative to the total theoretical demand.

Interactive Charts

References

• Original Source