What Is Rvp In Gasoline

It is defined as the absolute vapor pressure exerted by the vapor of the liquid and any dissolved gases moisture at 37 8 c 100 f as determined by the test method astm d 323 which was first developed in 1930 and has been revised several times the latest version is astm d323 15a.

What is rvp in gasoline. Rvp is the vapor pressure of gasoline measured at 100 degrees fahrenheit. Federal law prohibits gasoline with a reid vapor pressure rvp greater than 9 0 pounds per square inch to be sold at retail stations from june 1 through september 15. Because the fuel rule was retained as a contingency measure it remains on the boutique fuel list. See 77 fr 23619 april.

Alabama rvp of 7 0 psi. Reid vapor pressure is the pressure exerted by a liquid to calculate the volatile nature of gasoline. The pressure is exerted at a specific temperature that is 100 degrees fahrenheit. Rvp is not.

Implementation of alabama s 7 0 psi gasoline rvp rule was suspended when epa approved alabama s request to move the rule to the contingency measure portion of the sip for the birmingham area. Rvp is an abbreviation for reid vapor pressure a common measure of and generic term for gasoline volatility. Reid vapor pressure rvp is a common measure of the volatility of gasoline and other petroleum products. Reid vapor pressure is measured in gauge pressure and is stated in psi units.

Regulators worry about this evaporation because it contributes to ozone formation. Fuels with higher rvp evaporate more easily than those with lower rvp. A particular fuel blend s rvp is based on the combined rvp of the ingredients that make up the blend. The more volatile a gasoline higher rvp the easier it evaporates.

Winter blend fuel has a higher rvp because the fuel must be able to evaporate at low temperatures for the engine to operate properly especially when the engine is cold.