The 95 per cent distillation end point sits at 288 degrees Celsius for diesel one and 355 degrees Celsius for diesel two. The relative density of fuel, sometimes called the API specific gravity, refers to the amount of fuel per unit. Additional detailed information on areas where a SIP-approved state fuel rule applies can be found on the State Fuels webpage. deg. A diesel-fueled engine has no ignition source (such as the spark plugs in a gasoline engine), so diesel fuel can have a high flash point, but must have a low autoignition temperature. The cookie is used to store the user consent for the cookies in the category "Performance". Number 1 fuel oil is essentially kerosine. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. The lubricity of diesel fuel under ideal conditions is 3100. The vapour pressure of water is the pressure exerted by molecules of water vapor in gaseous form (whether pure or in a mixture with other gases such as air). What is the vapor pressure at 25 degrees Celsius? 9.6 Critical Pressure: Not pertinent 9.7 Specific Gravity: 0.80 at 15C (liquid) 9.8 Liquid Surface Tension: 23-32 dynes/cm = 0.023-0.032 N/m at 20C 9.9 Liquid Water Interfacial Tension: 47-49 dynes/cm = 0.047-0.049 N/m at 20C 9.10 Vapor (Gas) Specific Gravity: Not pertinent 9.11 Ratio of Specific Heats of Vapor (Gas): Not pertinent The vapor pressure of a liquid can be measured in many ways, e.g., by a manometer connected to the flask with the measured liquid. The relative density of fuel, sometimes called the API specific gravity, refers to the amount of fuel per unit. This calculator is one of the easiest to use, as you need to enter only one value, so you shouldn't have any problems with using it! Temperature. That for cetane is less than 1 mm mercury, yet another plus for cetane. The pour point of a liquid refers to the minimum temperature that liquid will pour or flow. Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a parts function at the center of their design considerations. When comparing vapor pressures we need to be making comparisons at the same temperature. The disadvantages of hydrostatic transmission, How to calculate superheat and subcooling, Turbo Direct Injection Club: Engine Manufacturers Association Recommended Guideline on Diesel Fuel, Diesel Fuels: Physical Properties of Diesel Fuels, U.S. Department of Energy: Alternative and Advanced Fuels, U.S. Department of Energy: Properties of Fuels. Her writing has also been in "Ictus" and "Struggle Creek: A Novel Story." The fuel volatility regulations have been transferred from 40 CFR 80.27 to 40 CFR 1090.215. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework. The test methodology defines the apparatus required to carry out the measurement, key test parameters, the procedure for the operator or automated apparatus to follow, and the precision of the test method. The pressure exerted by the vapor phase is called the. Alaska, Hawaii, and U.S. territories are exempted from federal volatility regulations. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Fischer, T. and Bjarnason, B.: Sensitizing and irritant properties of 3 environmental classes of diesel oil and their indicator dyes. For very low vapor pressures, errors can be much larger. Lubricity refers to a fluid's ability to minimise friction between two surfaces in motion with each other. What is causing the plague in Thebes and how can it be fixed? In chemistry, vapor pressure is the pressure that is exerted on the walls of a sealed container when a substance in it evaporates (converts to a gas). As of October 21, 2019, no Georgia counties are subject to the federal 7.8 psi volatility standard. What is Melting Point of Formed Compound? EPA published a final rule on July 2, 2015 (80 FR 38284) that relaxed the 7.8 psi federal RVP standard in Jefferson and Shelby counties. So it doesn't matter if we put our liquid into a wide flask or a thin graduated cylinder - the vapor pressure remains the same. Metal 3D printing has rapidly emerged as a key technology in modern design and manufacturing, so its critical educational institutions include it in their curricula to avoid leaving students at a disadvantage as they enter the workforce. Explain Distinction between Free Radical Reaction and Polar Reaction. Air is compressed until it heats above the autoignition temperature of the fuel, which is then injected as a high-pressure spray, keeping the fuel-air mix within flammable limits. Diesel was once thought to a be dirty, low-quality fuel source, but increased standards and regulations caused the quality of diesel to improve dramatically. That for cetane is less than 1 mm mercury, yet another 'plus' for cetane. The values start to differ significantly for temperatures higher than 100C100\ \degree\mathrm{C}100C, and the Antoine equation is usually the most accurate one. Vapor Pressure, also known as bubble point pressure and accurate vapor pressure, is the pressure where the primary bubble of vapor is shaped at a given temperature. Viscosity for diesel fuel at 40 degrees Celsius, or 40 degrees Celsius, should be between 2 to 4.4 * 10-5 ft^2/s. On December 4, 2020, EPA revised the federal RVP regulations. If you want to promote your products or services in the Engineering ToolBox - please use Google Adwords. Below are some selected values of temperature and the saturated vapor pressures required to place the boiling point at those temperatures. As of January 25, 2018, these 11 parishes are no longer subject to the 7.8 psi federal volatility standard. Viscosity for diesel fuel at 40 degrees Celsius, or 40 degrees Celsius, should be between 2 to 4.4 * 10-5 ft^2/s. Data sources: Most metals use the fits from C.B. 360 - 385. EPA set the Reid Vapor Pressure (RVP) standard at 9.0 psi for designated volatility attainment areas and the RVP standard at 7.8 psi for certain designated volatility nonattainment areas. 4D fuels tend to be used in low-speed engines. Now as you know what vapor pressure is and you heard about different vapor pressure formulas, it's high time for a practical demonstration. The rule was effective on publication. When provided with an ignition source, fuel ignites or flashes at its flash point. To find the vapor pressure at a given temperature, use the Clausius-Clapeyron equation: ln(P1/P2) = (Hvap/R)((1/T2) (1/T1)). At this point, there are as many molecules leaving the liquid and entering the gas phase as there are molecules leaving the gas phase and entering the liquid phase. Wood. As vapor pressure increases, the concentration of vapor of a flammable or combustible liquid in the air increases. CEN/TR 15138 Guide to Flash Point Testing and ISO TR 29662 Guidance for Flash Point Testing cover the key aspects of flash point testing. : Acute tubular necrosis after exposure to diesel oil. log 10 (P) = A (B / (T + C)) P = vapor pressure (bar) T = temperature (K) Temperature (K) A B C Reference Comment; 273.13 - 297.89: 4.23679: 1426.448-45.957: Besley and Bottomley, 1974: Coefficents calculated by NIST from author's data. The absolute vapour pressure of a liquid occurs at 37.8 degrees Celsius or 37.8 degrees Celsius. The vapor pressure will be relatively low for substances with stronger intermolecular forces. The cookie is used to store the user consent for the cookies in the category "Other. Assume we want to calculate the vapor pressure of water in 86F86\ \degree\mathrm{F}86F (30C30\ \degree\mathrm{C}30C). Solving for pv at 100C yields. (See 85 FR 78412.) *Eng-Tips's functionality depends on members receiving e-mail. The relative density of diesel should be between 31 and 40. Vapor pressure | McKinsey Energy Insights The fuel is mixed with air within its flammable limits and heated by compression and subject to Boyle's Law above its flash point, then ignited by the spark plug. Distillation measures the temperature range at which a fuel either becomes volatile or becomes a vapour. 70 deg F = 0.0090. SATURATED VAPOR PRESSURE Temperature (degrees F) Pounds per square inch 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 0.094 0.124 0.163 0.211 0.272 0.347 0. . What should the viscosity of diesel fuel be? That for toluene is 50 to 100 p.p.m. A straw yellow to dark colored liquid with a petroleum-like odor. 90 - 100. temperature of a liquid increases (TT\uparrowT) kinetic energy of its molecules increases (EkE_{\mathrm{k}}\uparrowEk) number of molecules transitioning into a vapor increases vapor pressure increases (PP\uparrowP). P0 A PA = PA = XBP0 A. (2) Y ct =Mass emissions as calculated from the "transient" phase . Type negative temperatures into the calculator and the vapor pressure will be determined according to Buck and Teten's formulas. Thank you for helping keep Eng-Tips Forums free from inappropriate posts.The Eng-Tips staff will check this out and take appropriate action. Pipelines, Piping and Fluid Mechanics engineering Forum, http://www.epa.gov/ttn/chief/ap42/index.html, Low-Volume Rapid Injection Molding With 3D Printed Molds, Industry Perspective: Education and Metal 3D Printing. EPA published a final rule on June 7, 2017 (82FR 26354) that relaxed the 7.8 psi federal RVP standard in Davidson, Rutherford, Sumner, Williamson, and Wilson Counties. Fluid Name: Temp. Join your peers on the Internet's largest technical engineering professional community.It's easy to join and it's free. - 343. What is the relative density of diesel fuel? Vapor Pressure Calculator [IAP/TU Wien] The vapor pressure of a liquid is the point at which equilibrium pressure is reached, in a closed container, between molecules leaving the liquid and going into the gaseous phase and molecules leaving the gaseous phase and entering the liquid phase. Fischer, T. and Bjarnason, B.: Sensitizing and irritant properties of 3 environmental classes of diesel oil and their indicator dyes. Example 1. B The vertical line corresponding to 250C intersects the vapor pressure curve of mercury at P 75 mmHg. What is the Vapour pressure of diesel? - Sage-Answer Fuel oil, [diesel], Last Updated Date : 10% of the temperature especially at high temperatures. This cookie is set by GDPR Cookie Consent plugin. We also use third-party cookies that help us analyze and understand how you use this website. The vapor pressure at 20 degrees Celcius for the following substances is Methyl alcohol 96 torr Acetic acid 11.7 torr Benzene 74.7 torr Bromine 173 torr Water 17.5 torr Carbon tetrachloride 91 torr Mercury 0.0012 torr Toluene 23 torr and arrange these substances in order of increasing rate of evaporation. The cookies is used to store the user consent for the cookies in the category "Necessary". Milton Beychok(Contact me at www.air-dispersion.com). Already a Member? Use one of the popular approximations, e.g., Antoine formula. 12/28/2020, Occupational Safety & Health Administration, Occupational Safety and Health Administration, Outreach Training Program (10- and 30-hour Cards), OSHA Training Institute Education Centers, Severe Storm and Flood Recovery Assistance, 68334-30-5; 68476-30-2; 68476-31-3; 68476-34-6; 77650-28-3. by Tim Brice and Todd Hall. The Engine Manufacturers Association, with approval from the United States Department of Energy, put out a recommended guideline designed to define the limitations of key physical properties for diesel fuel in order to maintain its newly improved quality level. The Engine Manufacturers Association, with approval from the United States Department of Energy, put out a recommended guideline designed to define the limitations of key physical properties for diesel fuel in order to maintain its newly improved quality level. Copyright 1998-2023 engineering.com, Inc. All rights reserved.Unauthorized reproduction or linking forbidden without expressed written permission. See Air Quality Designations and Classifications for the 8-Hour Ozone National Ambient Air Quality Standards; Early Action Compact Areas With Deferred Effective Dates, 69 Fed. EPA issued a final rule on September 1, 2015 (80 FR 52627) that removed the Georgia gasoline program that covered a 45-county Atlanta area from the States approved SIP. 23858 (August 30, 2004) (codified at 40 CFR part 81). If you're unsure what vapor pressure is, keep scrolling. P2 is the partial pressure of the liquid at T2. Understanding pressure effects. Vapour pressures of diesel at room temperature are very low; that discussed in has a vapor pressure of 0.4 mm Hg (E 0.053 kPa). The relative density of fuel, sometimes called the API specific gravity, refers to the amount of fuel per unit. 20800. Some of our calculators and applications let you save application data to your local computer. What is the vapour pressure of cetane diesel? PDF KEROSENE KRS - National Oceanic and Atmospheric Administration It works for many substances, although you need to know the coefficients. Designations and exact boundaries of the ozone nonattainment areas subject to the 7.8 psi RVP standard were published in the November 6, 1991, notice that designated areas pursuant to CAA section 107(d)(4)(A)(ii). Vapor pressure - PetroWiki The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. The vessel temperature was increased from 250C to 280C wile keeping the volume from part the same. What is the relative density of diesel fuel? K. Delimiter: Tab Space Comma (,) Semicolon (;) Accuracy: For many substances, vapor pressures are only poorly known; expect errors up to a few 10% of the vapor pressure value and up to approx. Registration on or use of this site constitutes acceptance of our Privacy Policy. Fuel oil, [diesel], NIOSH: Pocket Guide to Chemical Hazards - Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. is the boiling point in degrees Celsius and the pressure is in Torr. * Gas density in atoms or molecules per volume, assuming a monatomic gas unless the substance is given as molecule. These rules reduce gasoline emissions of volatile organic compounds (VOC) that are a major contributor to ground-level ozone (smog). What is Diesel Fuel The Reid vapour pressure measures the volatility of fuels. Enter a temperature or a dewpoint or both: Vapor Pressure. Original version - June 2019. The flash point is an empirical measurement rather than a fundamental physical parameter. 4.08245: 1346.382-53.508: Gaw and Swinton, 1968: Coefficents calculated by NIST from author's . The most often used is the Antoine equation (4.232kPa4.232\ \mathrm{kPa}4.232kPa), but the Buck formula (4.245kPa4.245\ \mathrm{kPa}4.245kPa) is usually the most accurate one for temperature ranges we typically look for. Water and sediments shortens the life of fuel filters and negatively affects corrosion and microbial growth. Ash content measures the amount of metal within diesel fuel. Volatility is the property of a liquid fuel that defines its evaporation characteristics. 2.3. Hence, temperature determines the concentration of vapor of the flammable liquid in the air. At the boiling point molecules anywhere in the liquid may be vaporized. Thanks. The Physical Properties of Diesel Fuel | eHow UK (EN 60079-10-1). Hence this is the pressure required for mercury to boil at 250C. In addition to the Penskey-Martens flash point testers, other non-equilibrial testers include TAG and Abel, both of which are capable of cooling the sample below ambient for low flash point materials. EPA issued a final rule on September 20, 2019 (84 FR 49470) that that relaxed the 7.8 psi federal RVP standard in Cherokee, Clayton, Cobb, Coweta, DeKalb, Douglas, Fayette, Forsyth, Fulton, Gwinnett, Henry, Paulding, and Rockdale, Georgia. Caitlynn Lowe has been writing since 2006 and has been a contributing writer for Huntington University's "Mnemosyne" and "Huntingtonian." The temperature TTT is expressed in degrees Celsius and the vapor pressure PPP is in mmHg\mathrm{mmHg}mmHg. What is the specific volume of the vapor (ml/g)? Yes, vapor pressure increases with temperature as the molecules receive more energy to escape from the liquid phase and transition to the gas phase. Learn more about the RVP federal regulations. The rule was effective on May 30, 2014. These cookies track visitors across websites and collect information to provide customized ads. The absolute vapour pressure of a liquid occurs at 37.8 degrees Celsius or 37.8 degrees Celsius. The substance with the highest boiling point will have the lowest vapor pressure. Alternatively, if the vapor pressure at 70C is 105.37 kPa and is known, you can use the 70 to 90C temperature differential to calculate the slope and intercept and ultimately calculate pv = 35.79 psia = 246.79 kPa. As of June 7, 2017, no counties in Tennessee are subject to the 7.8 psi federal volatility standard. The vapor pressure of water calculator found the pressure according to five formulas. Where TTT is expressed in C\degree\mathrm{C}C and PPP in kPa\mathrm{kPa}kPa. The effective date of the rule is July 2, 2015. No odour threshold appears to have been established for cetane. We have received your request and will respond promptly. However, you may visit "Cookie Settings" to provide a controlled consent. This action updated many of EPAs existing gasoline, diesel, and other fuel quality programs. Below is a summary of the federal fuel volatility regulations at 40 CFR 1090.215: The following is a list of all actions that EPA has taken since 2014 to either relax the federal 7.8 psi RVP standard or to remove state fuel regulation from the states approved SIP: EPA issued a final rule on May 22, 2014 (79 FR 29362) that relaxed the 7.8 psi federal RVP standard in Davidson, Davie, Durham, Forsyth, Granville, Guilford and Wake Counties . Google use cookies for serving our ads and handling visitor statistics. 6 What is the vapor pressure at 25 degrees Celsius? Vapor pressure: 2.17 mmHg Flash point: 125F Vapor density: Specific gravity: 0.841 at 60.8F . 90 deg F = 0.016. That's the value I've got and I'm sticking to it. East Baton Rouge, West Baton Rouge, Livingston, Ascension, and Iberville (the Baton Rouge Area), Louisiana; and Login. And at 20 deg C water will have 2.34 KPa as vapour pressure. Vapour Pressure of Diesel Fuel - QS Study Note that a closed container is required, as otherwise, the molecules in the gas phase will fly away. 100 mg/m (inhalable fraction and vapor) [2007], NOAA: CAMEO Chemicals - Is it Soluble in Water. EPA published a final rule on March 12, 2021 (86 FR 14000) that removed Kansas gasoline rule that applied to 2 counties in the Kansas portion of the Kansas City, KS-MO area from the approved SIP. Is water kept in a closed container at 20 degree Celsius - ResearchGate Certain SIP-approved fuel programs do not provide for use of a 1.0 psi ethanol waiver under 40 CFR 1090.215(b). Horrigan, Canadian Metallurgical Quarterly, 23, 309 (1984). Fluid Characteristics Chart Table | Fluids Data, Fluids Density | Vapor The value of 530 p.p.m. On July 5, 2019 (84 FR 32076) EPA published a final rule that removed the Allegheny County Health Departments rule that required the sale of 7.8 psi gasoline in Allegheny County from the SIP for the Pittsburgh area. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework. An official website of the United States government. A .gov website belongs to an official government organization in the United States. The table contains the geographic boundaries of these areas. As of April 7, 2017, no counties in Ohio are subject to the States 7.8 psi volatility requirement. The fire point is the lowest temperature at which the vapors keep burning after the ignition source is removed. So its correct to say water as saturated or subcooled liquid at 20 deg C with . In both these types, the cups are sealed with a lid through which the ignition source can be introduced. Login. You can also use another equation, called the Goff-Gratch formula, but as it's more complicated (and approximately as accurate as the Buck formula), we didn't implement it in our vapor pressure of water calculator. Metal 3D printing has rapidly emerged as a key technology in modern design and manufacturing, so its critical educational institutions include it in their curricula to avoid leaving students at a disadvantage as they enter the workforce. subject to a SIP-approved state fuel rule that requires an RVP of less than 9.0 psi must meet the requirements of the federally approved SIP. The rule was effective on May 30, 2014. We have received your request and will respond promptly. Click Here to join Eng-Tips and talk with other members! As of July 2, 2015, no Alabama counties are subject to the 7.8 psi federal volatility standard. A designated volatility nonattainment area is an area that is designated as being nonattainment for the ozone National Ambient Air Quality Standard (NAAQS) pursuant to a rulemaking under CAA section 107(d)(4)(A)(ii), and a designated volatility attainment area is an area not designated as being in nonattainment with the NAAQS for ozone. As temperature increases, vapor pressure increases. The measured value will vary with equipment and test protocol variations, including temperature ramp rate (in automated testers), time allowed for the sample to equilibrate, sample volume and whether the sample is stirred. The vapor pressure of water calculator is a handy tool that can help in determining the vapor pressure of water and ice. Lower RVP limits apply in areas that are: The regulatory text in 40 CFR 1090.215(a)(2) contains a table that lists the six areas that are currently subject to the federal 7.8 psi RVP standard. The Stage II system controls the release of VOC, benzene and toxics emitted from gasoline. Vapor pressure limits vary seasonally, with higher limits in the cold months and lower limits in the warm months. The boiling point is defined as the temperature at which the saturated vapor pressure of a liquid is equal to the surrounding atmospheric pressure. Vapor Pressure of Water Calculator | Definition | Formulas A certain concentration of a flammable or combustible vapor is necessary to sustain combustion in air, the lower flammable limit, and that concentration is specific to each flammable or combustible liquid. http://www.epa.gov/ttn/chief/ap42/index.html, Low-Volume Rapid Injection Molding With 3D Printed Molds, Industry Perspective: Education and Metal 3D Printing. AddThis use cookies for handling links to social media. 20F (approx.) The vapor pressure of water is the pressure at which water vapor is in thermodynamic equilibrium with its condensed state. EPA issued a direct final rule on August 17, 2015 (80 FR 49164) that relaxed the 7.8 psi federal RVP requirement in Mecklenburg and Gaston counties. It's a semi-empirical formula describing the association between vapor pressure and temperature. Anyone know the vapor pressure of #1 diesel fuel at. As of that date the sale of gasoline with an RVP of 7.8 psi was no longer required in Armstrong, Beaver, Butler, Fayette, Washington and Westmoreland Counties. Only emails and answers are saved in our archive. Additional detailed information on areas where federal RFG is required can be found on the Reformulated Gasoline webpage. The relative density of fuel, sometimes called the API specific gravity, refers to the amount of fuel per unit. 23.8 Phase II is applicable to 1992 and later calendar years. 2023 Leaf Group Ltd. / Leaf Group Media, All Rights Reserved. The density of petroleum diesel is about 0.85 kg/l about 1520% higher than the density of gasoline, which has a density of approximately 0.700.75 kg/l. Solved The vapor pressure at 20 degrees Celcius for the - Chegg Cherokee, Clayton, Cobb, Coweta, DeKalb, Douglas, Fayette, Forsyth, Fulton, Gwinnett, Henry, Paulding, and Rockdale, Georgia (the Atlanta RVP Area). The flash point is sometimes confused with the autoignition temperature, the temperature that causes spontaneous ignition. Note 1) Diesel fuels are in USA broken up into 3 different classes: 1D, 2D and 4D. Saturated Vapor Pressure, Density for Water Please read AddThis Privacy for more information. Depending on the state and month, gasoline RVP was not to exceed 10.5 pounds per square inch (psi), 9.5 psi, or 9.0 psi. EPA published a rule on October 24, 2018 (83 FR 53584) that relaxed the 7.8 psi federal RVP requirement for the Louisiana parishes of East Baton Rouge, West Baton Rouge, Livingston, Ascension, and Iberville (the Baton Rouge Area). C.C. 7 What is the relative density of diesel fuel? A The vapor pressure curve of water intersects the P = 1000 mmHg line at about 110C; this is therefore the boiling point of water at 1000 mmHg. Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a parts function at the center of their design considerations. There are many different formulas, thanks to which you can calculate the vapor pressure of water. Other examples can be given but enough has been said to support the view that the diesel concentration in the calculation is sufficient to be harmful. 56,694 (Nov. 6, 1991) (codified at 40 CFR part 81). The boiling point is defined as the temperature at which the saturated vapor pressure of a liquid is equal to the surrounding atmospheric pressure.For water, the vapor pressure reaches the standard sea level atmospheric pressure of 760 mmHg at 100C. Volatility is the property of a liquid fuel that defines its evaporation characteristics. . The absolute vapour pressure of a liquid occurs at 37.8 degrees Celsius or 37.8 degrees Celsius. Close this window and log in. Share sensitive information only on official, secure websites. That table has been replaced by regulatory text that explains that summer gasoline (e.g., gasoline that is sold to consumers between June 1st and September 15th) must meet a maximum per-gallon RVP limit of 9.0 psi unless it is required to meet a lower RVP limit. Diesel fuel reaches its accelerated stability at 15 mg/L. 11.5: Vapor Pressure - Chemistry LibreTexts If a fluid consist of more than one component (a solution), components with, At atmospheric pressure saturation temperature of. If you want the actual vapor pressure enter the dewpoint: Click Here to join Eng-Tips and talk with other members! The list of areas subject to the federal 7.8 psi RVP limit appears below: Denver-Boulder-Greeley-Ft. Collins-Loveland, Adams Arapahoe, Boulder, Broomfield, Denver, Douglas, Jefferson, Larimer,1 Weld2, Clackamas (only the Air Quality Maintenance Area), Multnomah (only the Air Quality Maintenance Area), Washington (only the Air Quality Maintenance Area), Marion (only the Salem Area Transportation Study), Polk (only the Salem Area Transportation Study). This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Specifically, vapor pressure is a measure of the volatility of a fuel, or the degree to which it vaporizes at a given temperature. EPA provides a 1.0 psi RVP allowance for gasoline containing 10 percent ethanol. Second, gasoline is a mixture of hydrocarbons, so there is no fixed value of a TRUE VAPOUR PRESSURE (thats the name for a vapour pressure at differnt temperature). 7840. In states that have received a waiver under Clean Air Act 211(c)(4)(C) to adopt a state fuel program, more stringent than federal requirements, into the federally-approved State Implementation Plan (SIP) the state fuel program may define a volatility level and compliance date for refiners and/or terminals different than the compliance date for retailers.
Introverted Thinking Test, Articles V