f) the use of incorrect conversion factors when converting between systems of measurement;
The shrinkage is greatest when the percentage of light or heavy component increases toward a 50/50 mixture. For additional details and the calculation procedures, see “API MPMS Chapter 12.3, Calculation of Volumetric Shrinkage Resulting from Blending Light Hydrocarbons with Crude Oil”. Although volumetric shrinkage is a reality, and can be significant in financial terms, the commercial parties to the transaction need to decide how this will be compensated for; and it should be decided at the time the sales contract is written. Any adjustments made as a result of volumetric shrinkage are strictly upon agreement of the commercial parties involved. NOTE: mass or weight is not affected by volumetric shrinkage.
7.6.10.7 Lightering
When cargo is transferred in a lightering operation, the quantity transferred may be better quantified by using the shuttle receipt quantity, adjusted by the VEF, rather than the quantity based on the delivering vessel. If weather or sea conditions during lightering were not conducive to accurate measurement, or measurements could not be obtained, the transferred quantity may be better quantified using the shuttle vessel’s arrival quantity (minus OBQ) at the discharge port, adjusted by the VEF. 7.6.10.8 Measurement Uncertainties and Errors Examples of possible errors that are not specific to a vessel or shore tank include:
g) random errors in measurement;
h) failure to use properly calibrated equipment;
i) failure to perform cargo measurement operations in accordance with API / EI standards;
use of multiple shore tanks.
j)
a) failure to follow proper operating practices;
7.6.10.6 Letter of Protest / Notice of Apparent Discrepancy
b) the use of defective or non-standard measurement equipment;
Any unusual event that occurred during a loading or discharge should have been reflected in the terminal or vessel time log, and possibly in a letter of protest or notice of apparent discrepancy. This documentation should be reviewed as part of any loss investigation.
c) the environment at the time the measurements are taken;
d) observed tank height differences between opening and closing measurements;
e) the use of incorrect tank tables or the improper use of tank capacity tables;
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