# Natural Gas Pipeline Flow Calculation Spreadsheet

## Choice of Equations for Natural Gas Pipeline Flow Calculations

Several different equations are used for natural gas pipeline flow calculations.  If the pressure drop across the pipe is less than 40 % of the average pipeline pressure, then the Darcy Weisbach equation is a possibility.  For longer pipelines with larger pressure drop, the three equations that are in most common use are the Weymouth equation, the Panhandle A equation, and the Panhandle B equation.  The choice among these three equations depends upon the pipeline diameter, the pipe length, and the average pipeline pressure.

## The Weymouth Equation for Natural Gas Pipeline Flow Calculations

The Weymouth equation was the first of the three to be developed and was the first equation for natural gas pipeline flow calculations that didn’t require an iterative calculation to get a value for the friction factor.  The Weymouth equation is:

Where:

• Q is the natural gas pipeline flow rate in SCFD
• E is the pipeline efficiency
• Tb is the base temperature in oR
• Pb is the base pressure in psia
• P1 is the inlet pressure in psia
• P2 is the outlet pressure in psia
• G is the specific gravity of the natural gas relative to air
• Tf is the pipeline temperature of the flowing natural gas in oR
• L is the pipeline length in miles
• Le  is the effective pipeline length in  miles
• ΔH is the height of the pipeline exit above the pipeline inlet in ft
• Z is the compressibility factor of the natural gas at pipeline T & P
• D is the pipeline diameter in inches.

## Example Spreadsheet for Natural Gas Pipeline Flow Calculations

A spreadsheet for Natural Gas Pipeline Flow Calculations is partially shown in the image below.  It can be used to calculate the natural gas pipeline flow rate with the Weymouth equation, the Panhandle A equation and the Panhandle B equation.  This Excel spreadsheet, as well as others for pipe flow calculations, is available in either U.S. or S.I. units for a very reasonable price in our spreadsheet store.

## References for Further Information:

1. Crane Co.,  (1988),  “Flow of Fluids through Valves, Fittings and Pipes,  Technical Paper 401.

2.  GPSA  (Gas Processors Suppliers Association),  (1988),  Engineering Data Book, 11th Ed.

3. Bengtson, Harlan H., (2016), “Natural Gas Pipeline Flow Calculations,”  available as a paperback book or as an Amazon Kindle ebook.

4.  Bengtson, Harlan H.,  (2017),   “Pipe Flow/Friction Factor Calculations with Spreadsheets“,  available as a paperback book or as an Amazon kindle e-book.

5. Bengtson, Harlan H., (2014),  “Natural Gas Pipeline Flow Calculation Spreadsheet“, a blog article at www.EngineeringExcelTemplates.com.