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'''Reid vapor pressure''' (RVP), as determined by the [[ASTM]] test method D323,<ref>Test method D323-08 of the [[American Society for Testing and Materials]](ASTM).</ref> is widely used in the petroleum industry as a measure of the volatility of [[petroleum crude oil]], [[gasoline]] and other volatile petroleum products. It is a quick and simple method of determining the vapor pressure at 37.8 °[[Celsius|C]] (100 °[[Fahrenheit and Rankine temperatures|F]]) of crude oil and petroleum products having an initial [[boiling point]] above 0 °C (32 °F). | '''Reid vapor pressure''' (RVP), as determined by the [[ASTM]] test method D323,<ref>Test method D323-08 of the [[American Society for Testing and Materials]] (ASTM). [http://www.astm.org/ABOUT/aboutASTM.html ASTM website]</ref> is widely used in the petroleum industry as a measure of the volatility of [[petroleum crude oil]], [[gasoline]] and other volatile petroleum products. It is a quick and simple method of determining the [[vapor pressure]] at 37.8 °[[Celsius|C]] (100 °[[Fahrenheit and Rankine temperatures|F]]) of crude oil and petroleum products having an initial [[boiling point]] above 0 °C (32 °F). | ||
== Importance and uses == | |||
Vapor pressure is an important physical property of volatile liquids. It is of critical importance for automotive and aviation gasolines since it affect the starting and warm-up of [[internal combustion engine]]s as well as the tendency to cause "vapor lock" in the fuel [[pump]]s with high operational [[temperature]]s and/or high altitudes. | |||
Air pollution regulatory authorities mandate maximum gasoline vapor pressures in many areas so as to limit the [[evaporation|evaporative]] emissions of [[smog]]-forming [[hydrocarbon]]s from gasoline. | |||
Vapor pressure is also important as an indirect measure of the evaporation tendency of volatile petroleum [[solvent]]s. | |||
== The difference between RVP and TVP == | |||
True vapor pressure is referred to in the petroleum industry as TVP. Both the Reid vapor pressure (RVP) and the true vapor pressure (TVP) are ''absolute'' pressures as distinguished from ''gauge'' pressures (see [[Pressure#Absolute pressure versus gauge pressure|Pressure]]). | |||
== References == | == References == | ||
{{reflist}} | {{reflist}} | ||
Revision as of 13:07, 26 October 2009
Reid vapor pressure (RVP), as determined by the ASTM test method D323,[1] is widely used in the petroleum industry as a measure of the volatility of petroleum crude oil, gasoline and other volatile petroleum products. It is a quick and simple method of determining the vapor pressure at 37.8 °C (100 °F) of crude oil and petroleum products having an initial boiling point above 0 °C (32 °F).
Importance and uses
Vapor pressure is an important physical property of volatile liquids. It is of critical importance for automotive and aviation gasolines since it affect the starting and warm-up of internal combustion engines as well as the tendency to cause "vapor lock" in the fuel pumps with high operational temperatures and/or high altitudes.
Air pollution regulatory authorities mandate maximum gasoline vapor pressures in many areas so as to limit the evaporative emissions of smog-forming hydrocarbons from gasoline.
Vapor pressure is also important as an indirect measure of the evaporation tendency of volatile petroleum solvents.
The difference between RVP and TVP
True vapor pressure is referred to in the petroleum industry as TVP. Both the Reid vapor pressure (RVP) and the true vapor pressure (TVP) are absolute pressures as distinguished from gauge pressures (see Pressure).
References
- ↑ Test method D323-08 of the American Society for Testing and Materials (ASTM). ASTM website