Reference: Gas Pipeline Hydraulics, 2005, CRC Press, E. Shashi Menon Chapter 2, page 67 Example 16


Pipe Flow Expert File: Case_05_Natural_Gas_Pipeline_Inlet_Pressure.pfe


Problem Description: 

Calculate the inlet pressure in a 24 km natural gas pipeline, with internal diameter 288 mm.  

The gas flow rate is 3.5 Mm3/day and the delivery pressure is 6000 kPa absolute.  

The average gas temperature is 20 °C, the pipeline efficiency is 0.92 and the gas compressibility factor is 0.90.


The calculation method used for the published data was the Panhandle A equation.


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Pipe Flow Expert Parameters:


Fluid Data: Gas specific gravity 0.6 (0.723 kg/m3), 20 °C, 0.00 kPa.g, viscosity 0.0119 centipoise.

Pipe Data: Pipeline efficiency = 0.92.

Flow Rate: 3.5 MMSCMD.

Calculation Method: Panhandle A Isothermal equation, Node Adjust Method.

Standard Atmospheric Model: 15 °C, 101.325 kPa.

Gas Physical Model: Real Gas Model (Ideal Gas Law with compressibility factor Z=0.9).


Result Comparison: 


Data Item

Published data

Pipe Flow Expert

Inlet pressure 

(kPa absolute)

7471

7480


Commentary: 

The published data and the calculated results compare well.


The publication states the gas flow rate is 3.5 Mm3/day.  Here, the ‘M’ stands for ‘one million’, which is not the same as the ‘M’ in “standard condition” units i.e. MSCMD.  In “standard condition” units a single ‘M’ stands for ‘one thousand’, and ‘MM’ stands for one million.