Line pack meter tab

Line Pack

Data Source

Line Pack EFM or Line Pack Host Calculated.

Physical Pipe

Volume

Volume of the pipe, which may be entered manually, or calculated using the Pipe Volume Calculator. Select the button to the right of the Value cell to open the Pipe Volume Calculator.

Note: This value is used to calculate the line pack.

Volumetric Calculation

Line Pack.

Note: This is the only choice for this field.

Avg Calculation

Linear or Non-Linear.

There are two calculation methods that may be used to estimate the volume of gas:

• The Linear calculation assumes that the pressure and temperature in the pipe changes linearly with distance, taking an average of the input and output values.

• The Non-Linear calculation assumes that temperature changes non-linearly with distance, by performing the following calculation:

  value = out + (in - out) / 3

• The Non-Linear calculation assumes that pressure changes non-linearly with distance, by performing the following calculation:

  sum = in + out

  value = (sum - (in * out / sum)) * 2/3

  Notes: Gas volume estimates from the Non-Linear calculation are more accurate than those from the Linear calculation. The Non-Linear calculation is as recommended by the following guide: Menon, E. S., & Menon, P. S. (2013). Gas pipeline hydraulics. Bloomington, IN: Trafford Publ.
  Inlet/outlet pressures are converted from gauge to absolute before calculating the average pressure for a line pack meter.