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

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This calculator requires JavaScript to compute its result. The formula, symbols, and regulatory sources are shown in the Formula section below.

Formula, assumptions, and limits

V_{purge} = V_{tank} \cdot \ln\left(\frac{c_0 - c_p}{c_t - c_p}\right)

Symbol	Meaning	Unit
$V_{tank}$	Tank gross volume	m³
$c_0$	Initial impurity concentration	%vol
$c_t$	Target concentration	%vol
$c_p$	Purge-gas impurity	%vol

Source: SIGTTO - Liquefied Gas Handling Principles 4th ed; IGC Code Ch. 9

In short

Nitrogen volume required to dilute an LNG cargo tank from initial O\u2082/HC concentration down to the target using a dilution (well-mixed) purge - the baseline method when displacement cannot be guaranteed.

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