HomeCalculatorsLNG Tank Inerting - Dilution Purge Volume

LNG Tank Inerting - Dilution Purge Volume

Nitrogen volume required to dilute an LNG cargo tank from initial O₂/HC concentration down to the target using a dilution (well-mixed) purge - the baseline method when displacement cannot be guaranteed.

LNGPurgeInerting
Tank volumes required
2.35× V
Total N₂ volume
58,784
Formula, assumptions, and limits

Dilution purge follows exponential decay (perfect mixing). Typical gas-freeing requires 3–4 tank volumes. Displacement purge (if density-layered) can achieve same target in ~1.05 × V.

Symbol legend

SymbolMeaningUnitSource
Tank gross volumecapacity plan
Initial impurity concentration%volgas analyser
Target concentration%volIGC/SIGTTO
Purge-gas impurity%volN₂ generator spec