Basic formula
Pipeline geometric volume V = π × D² ÷ 4 × L. Theoretical nitrogen demand is adjusted for purge factor, pressure basis and margin; actual demand must consider method, mixing, leakage and oxygen target.
APPLICATION
Pipeline Purging Nitrogen Systems
Calculated from pipeline volume, purge cycles, oxygen target, operation time and back pressure.
VolumePipe geometry
CyclesPurge method
TimeRequired duration
PressureBack-pressure checked
ENGINEERING NOTES
Define the duty before selecting equipment.
The following establishes a technical discussion framework. Final performance, scope, certification and acceptance criteria are defined in the agreed technical specification.
Flow and pressure
Short purge windows can create peak flow far above normal process demand. Line resistance, terminal back pressure, valve capacity and booster requirement must be calculated.
Safety note
The vent point can create an oxygen-deficient atmosphere. The project team must define venting, isolation, monitoring and permit procedures. Web calculations are for screening only and do not replace project safety engineering.
SYSTEM BOUNDARY
A deliverable system makes every critical interface explicit.
01 Feed air→02 Air treatment→03 Gas separation→04 Analysis & storage→05 Process user