Behaviour in previous versions (up to USC Assay 2026​.2)

In earlier versions, the volume expansion property was defined as follows:

(Equation 5)

In this equation, densities refer to the whole crude.

Using Equations 3 and 4 (see Expanded density (EXD)), Equation 5 can be rewritten as:

(Equation 6)

In Equation 6, total product volume can refer to any flowsheet, provided that no single product exceeds 70% by weight of the crude.