ASTM D664-17a
Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration

Standard No.

ASTM D664-17a

Release Date

2017

Published By

American Society for Testing and Materials (ASTM)

Status

Be replaced

Replace By

ASTM D664-18

Latest

ASTM D664-18e2

Scope

1.1 This test method covers procedures for the determination of acidic constituents in petroleum products, lubricants, biodiesel, and blends of biodiesel. 1.1.1 Test Method A—For petroleum products and lubricants soluble or nearly soluble in mixtures of toluene and propan-2ol. It is applicable for the determination of acids whose dissociation constants in water are larger than 10–9 ; extremely weak acids whose dissociation constants are smaller than 10–9 do not interfere. Salts react if their hydrolysis constants are larger than 10–9 . The range of acid numbers included in the precision statement is 0.1 mg ⁄g KOH to 150 mg ⁄g KOH. 1.1.2 Test Method B—Developed specifically for biodiesel and biodiesel blends with low acidity and slightly different solubility. This test method requires the use of an automatic titrator with automatic endpoint-seeking capability. NOTE 1—In new and used oils, the constituents that may be considered to have acidic characteristics include organic and inorganic acids, esters, phenolic compounds, lactones, resins, salts of heavy metals, salts of ammonia and other weak bases, acid salts of polybasic acids, and addition agents such as inhibitors and detergents. 1.2 The test method may be used to indicate relative changes that occur in oil during use under oxidizing conditions regardless of the color or other properties of the resulting oil. Although the titration is made under definite equilibrium conditions, the test method is not intended to measure an absolute acidic property that can be used to predict performance of oil under service conditions. No general relationship between bearing corrosion and acid number is known. NOTE 2—The acid number obtained by this standard may or may not be numerically the same as that obtained in accordance with Test Methods D974 and D3339. There has not been any attempt to correlate this method with other non-titration methods. NOTE 3—A few laboratories have made the observation that there is a difference in Test Method D664 results when aqueous versus nonaqueous buffers are used. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

ASTM D664-17a Referenced Document

• ASTM D1193 Standard Specification for Reagent Water
• ASTM D3339 Standard Test Method for Acid Number of Petroleum Products by Semi-Micro Color Indicator Titration
• ASTM D4057 Standard Practice for Manual Sampling of Petroleum and Petroleum Products
• ASTM D4177 Standard Practice for Automatic Sampling of Petroleum and Petroleum Products
• ASTM D974 Standard Test Method for Acid and Base Number by Color-Indicator Titration
• ASTM E177 Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods

ASTM D664-17a history

• 2018 ASTM D664-18e2 Test Method for Determination of Flexible Creep Hardness of Asphalt Binders Using a Bending Beam Rheometer
• 2018 ASTM D664-18e1 Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration
• 2018 ASTM D664-18 Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration
• 2017 ASTM D664-17a Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration
• 2017 ASTM D664-17 Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration
• 2017 ASTM D664-11a(2017) Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration
• 2011 ASTM D664-11ae1 Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration
• 2011 ASTM D664-11a Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration
• 2011 ASTM D664-11 Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration
• 2009 ASTM D664-09a Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration
• 2009 ASTM D664-09 Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration
• 2007 ASTM D664-07 Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration
• 2006 ASTM D664-06ae1 Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration
• 2006 ASTM D664-06a Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration
• 2006 ASTM D664-06 Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration
• 2004 ASTM D664-04e1 Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration
• 2004 ASTM D664-04 Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration
• 2001 ASTM D664-01 Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration
• 1995 ASTM D664-95(2001)e1 Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration
• 1995 ASTM D664-95 Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration