What Is Rvp In Gasoline

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.

What is rvp in gasoline.

The more volatile a gasoline higher rvp the easier it evaporates. 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. Reid vapor pressure is measured in gauge pressure and is stated in psi units. The pressure is exerted at a specific temperature that is 100 degrees fahrenheit.

It is determined by a test known as astm d 323. Regulators worry about this evaporation because it contributes to ozone formation. Reid vapor pressure rvp is a common measure of the volatility of gasoline and other petroleum products. Reid vapor pressure is the pressure exerted by a liquid to calculate the volatile nature of gasoline.

Alabama rvp of 7 0 psi. Because the fuel rule was retained as a contingency measure it remains on the boutique fuel list. 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. Fuels with higher rvp evaporate more easily than those with lower rvp.

Rvp is a measure of how easily the fuel evaporates at a given temperature. Rvp is not. A particular fuel blend s rvp is based on the combined rvp of the ingredients that make up the blend. 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.

Rvp is the vapor pressure of gasoline measured at 100 degrees fahrenheit.