Vapor Return - Rate vs Load Rate
Vapor-return gas volume during loading - matches the liquid load rate corrected for tank ullage temperature, used to size VECS manifold.
T correction
1.052 -
Vapor return rate
2,104m³/h
Formula, assumptions, and limits
$$\dot V_{vap} = \dot V_{liq} \cdot \frac{T_{tank}}{T_{ref}}$$
Ignore small pressure corrections at near-atmospheric operation. MARPOL Annex VI Reg. 15 requires approved VECS for any terminal with loadings of crude / gasoline / aromatic exceeding 1 Mt/yr.
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $\dot V_{liq}$ | Cargo loading rate | m³/h | loading plan |
| $T_{tank}$ | Tank vapor temperature | K | tank gauge |
| $T_{ref}$ | Terminal reference T | K | terminal spec |
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