API MPMS 12.3:1996(2006) pdf download
API MPMS 12.3:1996(2006) pdf download.Manual of Petroleum Measurement Standards Chapter 12- Calculation of Petroleum Quantities Section 3- -Volumetric Shrinkage Resulting From Blending Light Hydrocarbons
With Crude Oils.
6 Precautions on Use of the New MPMS Chapter 12.3 Equations and Tables
8.1 EFFECT OF TEMPERATURE AND PRESSURE ON VOLUMETRIC SHRINKAGE
The new correlation Is based on experimental data gathered at conditions of absolute pressure in the range of 100-700 blopascals. 15-I IS pounds per square inch absolute, and temperatures near 15°C or 60°F. Thus, it is recommended that all shrinkage calculations be limited to conditions within that range.
8.2 DIFFERENCE BETWEEN CUSTOMARY AND METRIC TABLES
Shrinkage factors obtained from Table 3 in customary units will not necessarily be numerically equivalent to factors detemuned from Tables 4 and 5 in SI units. This difference is paniaily the result of the difference in standard temperatures (60°F versus 15°C), but even after volume correction using the API correlation, shrinkage factoes may show a relative difference of as much as 0.4 percent. For custody transfer purposes, it is therefore recommended that buyers and seLlers agree on which set of tables they will use.
6.3 UMITATIONS AND ALTERNATIVES
The correlation equation or tables given in this text can predict volumernc shrinkage within the stated precision for mixtures of hydrocarbons over a relatively wide range in density difference and mixture ratios. However, the available experimental data suggest that factors other than density difference affect the volumetric behavior. Current understanding is insufficient to allow accurate prediction of the effect of composition. and thus experimental confirmation is recommended for hydrocarbon types not represented in the existing data sets. It is recommended that when an accurate shrinkage is required for spe. cific mixtures or when there are extenuating circumstances that may make use of the shrinkage tables questionable. the shrinkage may be determined by testing the individual components in a qualified lab using one of the test methods included in Appendix C.
6.4 EXCLUSIONS
Users of this standard are cautioned that thc equations presented are strictly empirical in nature, derived by obtaining a “best fit” between availablc experimental data and values predicted by a mathematical equation. For this reason, the equation should only be used to predict shrinkage for mixtures within the overall density range shown in Table 1. In addition, although the influence of parameters other than density difference is not addre.sscd in this correlation, there is indication within the available data that shrinkage is affected by compositional and other variations.
The tables or equations provided here are not to be used for volumetric corrections that might be necessary for the blending of gasoline components (including oxygenates, or the newer reformulated fueLs) as these materials were not included in the data referenced above.
This table is entered with the difference in API gravity between the light and heavy hydrocarbon components and the percentage by volume of the light hydrocarbon in die mix to obtain a percentage shrinkage of the total volume of the mixture. Multiplication of the percentage factor extracted from the table (divided by 100) by the total volume of the mixture equals the volumetric shrinkage that occurs from mixing the light with the heavy hydrocarbon component
b Inverse Density Difference in m3lkg X I& for Light Hydrocarbon Densaties from 580
to 890 kg/rn3 at 15°C and Heavy Hydrocarbon Densities from 980 to 640 kg/rn3 at 15°C
(Table 4—Memc)
This table is entered with the densities of the light and heavy components in kilograms per cubic meter to obtain the inverse of the light component density (dL) minus the inverse of the heavy component density (dH). required to enter the SI version Table 5, for determination of volumcmc shrinkage.
c. Volumetric Shrinkage Percentage Factors fo Blending Two Hydrocarbons with Differences in Inverse Densities at 15°C in m3/kg Determined from Table 4 and from I to 99 Percent Light Hydrocarbon Component in Total Blend (Table 5—Metric).
