Gas Pipeline Hydraulics Calculator

Calculation Mode:

Pressure Drop Flow Capacity Size Pipeline

Flow Equation:

Weymouth Panhandle A Panhandle B AGA

Pipeline Dimensions

Inside Diameter

Pipeline Length

miles

Pipe Roughness

Efficiency Factor (E)

Operating Conditions

Flow Rate

MMSCFD

Inlet Pressure (P₁)

psig

Average Temperature

°F

Gas Properties

Gas Gravity (Air=1.0)

Elevation Change

Typical Values:
• Gas Gravity: 0.55-0.65 (natural gas)
• Roughness: 0.0007" (new), 0.002" (aged)
• Efficiency: 0.95 (new), 0.92 (good), 0.85 (fair)
• Elevation: + uphill, - downhill

📚 Learn the Theory

Understand pipeline hydraulics principles, calculations, and industry applications

Read Engineering Guide →

📋 Mode 1: Calculate Pressure Drop

Use when designing a new pipeline or verifying an existing system. Input the desired flow rate and inlet pressure to find the resulting outlet pressure and pressure drop. Most common calculation for pipeline design.

Application: Pipeline sizing, capacity verification, operational planning

Given: Flow rate (Q), Inlet pressure (P₁), Diameter (D)

Calculate: Outlet pressure (P₂), Pressure drop (ΔP)

🔬 Equation Selection Guide

Weymouth: High-pressure transmission (>500 psig), D>12" - most conservative
Panhandle A: Older pipes, moderate roughness
Panhandle B: New/smooth pipes, fully turbulent - most optimistic
AGA: General purpose, uses Colebrook-White friction factor

Engineering Notes

Flow Equations (ASME B31.8)

Weymouth:
Q = 433.5 E (Tᵦ/Pᵦ) √[(P₁²-P₂²)D⁵/(G·Tₐᵥ·Lₑ·Z)]

Q = Flow rate (scfd)

P₁, P₂ = Inlet/outlet pressure (psia)

D = Inside diameter (in)

E = Efficiency factor

Z = Compressibility factor

Standards & References

ASME B31.8-2020
Gas Transmission and Distribution Piping Systems (Section 841, Appendix C)
API RP 14E
Design and Installation of Offshore Production Platform Piping Systems
AGA Report No. 8
Compressibility Factors of Natural Gas
Lee et al. (SPE 1340)
Viscosity of Natural Gases

Important Notes

Base Conditions: 14.7 psia, 60°F (standard cubic feet)
Compressibility: Uses Standing-Katz correlation for Z-factor
Viscosity: Lee-Gonzalez-Eakin correlation
Erosional Velocity: API RP 14E check (Ve = 100/√ρ)
Elevation: Positive = uphill (increases ΔP)
Valid For: Single-phase gas only, steady-state flow
Professional Review: Verify with licensed PE for final design