LINE PACK

Line Pack quantifies pipeline inventory: the gas held in a line at operating pressure, and the pumping time required to pack a slack line to a target pressure.

Capabilities

• Static Inventory — standard gas volume and mass held across a multi-section pipeline, with average compressibility, average density and a section-by-section breakdown.
• Dynamic Line Fill — pump run time and displaced liquid volume to raise a slack line to a target packing pressure, for a constant flow rate (VFD or flow control valve) or a fixed-speed pump running down its curve, reported separately.
• Packing pressure checked against the fluid’s calculated bubble point.
• Pipe dimensions by ASME B36.10M nominal size and schedule.
• Exportable PDF report.

Why the results hold up

Inventory is evaluated at the integrated mean pressure of the line’s compressible pressure profile, not the arithmetic mean of inlet and outlet pressure. Density and compressibility come from the Peng-Robinson equation of state for the actual composition. Standard volumes are reported on an explicit ISO 13443 reference-condition basis. Line fill solves Peng-Robinson phase equilibria to establish the bubble point the packing pressure must exceed.

Scope

Temperature is taken as a steady-state arithmetic mean across each section. The bubble-point comparison applies at that temperature; vapour trapped at high points, temperature variation along the route and transients during valve movement are outside the calculation.