RVP vs TVP

[rajdeepvirdi]

What's the difference?

[carlo.stenali]

you should refer to API TDB or specialized books as Characterization and Properties of Petroleum Fractions for the details,
the most important here is TVP which is the saturation pressure of a fluid (pure or mixture)
looking a phase envelope it's a point on the bubble line,
you can estimate TVP with a simulator,
I use PRODE PROPERTIES with EXCEL so, to calculate TVP at specified temperature I use the macro
=LFPf(1,t,1.0)
which returns directly saturation pressure (or TVP)
instead Reid Vapor Pressure (RVP) is generally evaluated with a specific measuring tool but you can calculate RVP as well (with software as PRODE PROPERTIES),
there is a difference between TVP and RVP but there are empirical correlations to convert RVP to TVP