The Weymouth Equation gives more conservative results than the Panhandle equations, and is hence more frequently used. It is valid for steady-state adiabatic (isothermal) flow. The version of the Weymouth equation used in this spreadsheet also accounts for elevation differences between the pipe entrance and exit.

In Imperial units, the Weymouth equation is

Tsc and Psc are the temperature and pressure at standard conditions, in absolute Fahrenheit

Tm is the average temperature of the gas line, in absolute Fahrenheit

P1 and P2 are the pressures at the pipe entrance and exit, in absolute psi

L is the length of the pipe, in miles

G is the relative gas density with respect to air

Z is the gas compressibility

E is the pipeline efficiency

Le is the effective length of the pipeline

Δz is the elevation of the pipe exit with respect to the entrance in feet

Q is the flowrate, in standard cubic feet per day

The gas compressibility Z and density are calculated at an average pressure and temperature, defined below.

The equations given above use several empirical factors, and normally the input parameters would need to be specified in specific units. However, I've programmed the spreadsheet to handle the unit conversions for you. You simply specify the input units using drop-down menus.

For dry gas fields, the pipeline efficiency is generally around 0.92, casing-head gas would have a pieline efficiency of 0.77, while gas and condensate pipes have an efficiency of 0.66

The Weymouth Equation gives more conservative results than the Panhandle equations, and is hence more frequently used. It is valid for steady-state adiabatic (isothermal) flow. The version of the Weymouth equation used in this spreadsheet also accounts for elevation differences between the pipe entrance and exit.

Tsc and Psc are the temperature and pressure at standard conditions, in absolute Fahrenheit

The gas compressibility Z and density are calculated at an average pressure and temperature, defined below.

The equations given above use several empirical factors, and normally the input parameters would need to be specified in specific units. However, I've programmed the spreadsheet to handle the unit conversions for you. You simply specify the input units using drop-down menus.

For dry gas fields, the pipeline efficiency is generally around 0.92, casing-head gas would have a pieline efficiency of 0.77, while gas and condensate pipes have an efficiency of 0.66

The Weymouth Equation gives more conservative results than the Panhandle equations, and is hence more frequently used. It is valid for steady-state adiabatic (isothermal) flow. The version of the Weymouth equation used in this spreadsheet also accounts for elevation differences between the pipe entrance and exit.

The equations given above use several empirical factors, and normally the input parameters would need to be specified in specific units. However, I've programmed the spreadsheet to handle the unit conversions for you. You simply specify the input units using drop-down menus.

The Weymouth Equation gives more conservative results than the Panhandle equations, and is hence more frequently used. It is valid for steady-state adiabatic (isothermal) flow. The version of the Weymouth equation used in this spreadsheet also accounts for elevation differences between the pipe entrance and exit.

The Weymouth Equation

ParametersInlet pressure (absolute) 1000Outlet pressure (absolute) 946.2Pressure, std condition (absolute) 14.7Temperature std condition (absolute) 520Mean temperature of line (absolute) 530Inside diameter 17.5Pipe length 20Gas relative density (air=1) 0.6Mean gas compressibility 0.85Pipeline efficiency 0.95Mean gas viscosity 1Elevation of exit above entrance 400

ResultFlowrate (std conditions) 1.3136E+08

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Pressure units Temperature Units Length units

psia F inPa K m

miles

Inlet pressureOutlet pressurePressure, std conditionTemperature std conditionMean temperature of lineInside diameterPipe lengthGas relative density (air=1)Mean gas compressibilityPipeline efficiencyPipe effective roughnessMean gas viscositysLe

Weymouth equation

Viscosity Volume flowrate

Pa s ft^3/daycP m^3/s

Unit Value in Imperial1 10001 946.21 14.71 5201 5301 17.53 20

2 11 0.00166481687014

20.0166574112654131355536.113474

1 1.3236E+08 132356451