3 replies to this topic

[happy]

Hi! so I'm new here, I actually came across this forum while looking up the topic and found no answer, so I thought posting here might help. I'm reading a document on Reid Vapour Pressure (RVP) and True Vapour Pressure (TVP), and it mentions the RVP is commonly about 6% less than TVP at 100 degrees Farenheit. Which I don't get, if RVP has air included, should'nt it have a higher pressure value?

any thoughts on the matter is highly appreciated! thanks!

[happy]

and no one answered...because?!?!?

[Profe]

Hi Happy

Don't be unhappy because I was very very busy.

First of all try this link: http://www.bre.com/B...40/Default.aspx

or another one: http://newsgroups.de...8/msg00033.html this last link has another link to pdf file for a nomograph for convert TVP to Rvp: http://www.epa.gov/t...inal/c07s01.pdf
In Figure 7.1-14a it has a True vapor pressure & Reid Vapor Pressure Nomograph
and the figures 7.1.13b and 7.1.14b has mathematical relationships for Tvp as function of Rvp.
Good luck in your search. I used Google.

If you are patient, I will review my sources of information for this topic.

[ADL]

Evaporation losses are related to the true vapor pressure (TVP) of liquids at their storage temperature. The common test for petroleum fractions is the RVP test defined by the American Society for Testing and Materials under the designation ASTM D323-56. The American Petroleum Institute (API) describes the RVP test procedure in detail, including the apparatus. Other API publications show charts relating RVP and ASTM boiling characteristics of gasoline’s and crude oils to TVP, a way to estimate RVP of blends, and the relation of RVP to evaporation losses.