The API method (API) may be used to predict liquid densities at flowing conditions. A standard liquid density is computed at 60 degrees F, using the weight average of the component densities. The reduced temperature and pressure of the mixture at 60 degrees F and 14.6959 psia are computed with Kay's rule and used to determine a density factor, C, from Figure 6A2.22 in the API Technical Data Book. A second factor is determined at the flowing temperature and pressure for the mixture and the flowing density is computed from the equation below:
See "API" under "Generalized Correlation Methods" in Chapter 2, Volume 1, of the PRO/II Reference Manual for more information.
Application Guidelines
The method is applicable to most hydrocarbon systems, provided that the reduced temperature is less than 1.0.