ASTM D6468-22

Standard Test Method for High Temperature Stability of Middle Distillate Fuels

SIGNIFICANCE AND USE
5.1 This test method provides an indication of thermal oxidative stability of distillate fuels when heated to high temperatures that simulate those that may occur in some types of recirculating engine or burner fuel delivery systems. Results have not been substantially correlated to engine or burner operation. The test method can be useful for investigation of operational problems related to fuel thermal stability.  
5.2 When the test method is used to monitor manufacture or storage of fuels, changes in filter rating values can indicate a relative change in inherent stability. Storage stability predictions are more reliable when correlated to longer-term storage tests, for example, Test Method D4625, or other lower temperature, long-term tests. When fuel samples are freshly produced, aging for 180 min, instead of the traditional 90 min interval, tends to give a result correlating more satisfactorily with the above methods (see Appendix X2).  
5.3 The test method uses a filter paper with a nominal porosity of 11 μm, which will not capture all of the sediment formed during aging but allows differentiation over a broad range. Reflectance ratings are also affected by the color of filterable insolubles, which may not correlate to the mass of the material filtered from the aged fuel sample. Therefore, no quantitative relationship exists between the pad rating and the gravimetric mass of filterable insolubles.
SCOPE
1.1 This test method covers relative stability of middle distillate fuels under high temperature aging conditions with limited air exposure. This test method is suitable for all No. 1 and No. 2 grades in Specifications D396, D975, D2880, and D3699. It is also suitable for similar fuels meeting other specifications.  
1.2 This test method is not suitable for fuels whose flash point, as determined by Test Methods D56, D93, or D3828, is less than 38 °C. This test method is not suitable for fuels containing residual oil.  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3.1 Exception—The maximum vacuum includes inch-pound units in 6.5 and 11.2.  
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.

General Information

• Status: Published
• Publication Date: 30-Apr-2022
• ICS: 27.060.10 - Liquid and solid fuel burners
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.14 - Stability, Cleanliness and Compatibility of Liquid Fuels

Relations

• Refers: ASTM D93-20 - Standard Test Methods for Flash Point by Pensky-Martens Closed Cup Tester
• Effective Date: 01-Aug-2020

Standards Content (Sample)

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.
Designation: D6468 − 22
Standard Test Method for
1
High Temperature Stability of Middle Distillate Fuels
This standard is issued under the fixed designation D6468; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* D396Specification for Fuel Oils
D975Specification for Diesel Fuel
1.1 This test method covers relative stability of middle
D1500Test Method forASTM Color of Petroleum Products
distillate fuels under high temperature aging conditions with
(ASTM Color Scale)
limited air exposure. This test method is suitable for all No. 1
D2274TestMethodforOxidationStabilityofDistillateFuel
and No. 2 grades in Specifications D396, D975, D2880, and
Oil (Accelerated Method)
D3699. It is also suitable for similar fuels meeting other
D2880Specification for Gas Turbine Fuel Oils
specifications.
D3699Specification for Kerosine
1.2 This test method is not suitable for fuels whose flash
D3828Test Methods for Flash Point by Small Scale Closed
point, as determined by Test Methods D56, D93,or D3828,is
Cup Tester
less than 38°C. This test method is not suitable for fuels
D4057Practice for Manual Sampling of Petroleum and
containing residual oil.
Petroleum Products
1.3 The values stated in SI units are to be regarded as D4175Terminology Relating to Petroleum Products, Liquid
Fuels, and Lubricants
standard. No other units of measurement are included in this
standard. D4625Test Method for Middle Distillate Fuel Storage
Stability at 43°C (110°F)
1.3.1 Exception—The maximum vacuum includes inch-
pound units in 6.5 and 11.2. D5452Test Method for Particulate Contamination in Avia-
tion Fuels by Laboratory Filtration
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3. Terminology
responsibility of the user of this standard to establish appro-
3.1 Definitions:
priate safety, health, and environmental practices and deter-
3.1.1 For definitions of terms used in this test method, refer
mine the applicability of regulatory limitations prior to use.
to Terminology D4175.
1.5 This international standard was developed in accor-
3.2 Definitions of Terms Specific to This Standard:
dance with internationally recognized principles on standard-
3.2.1 adherent insolubles, n—material that is produced in
ization established in the Decision on Principles for the
the course of stressing distillate fuel under the conditions of
Development of International Standards, Guides and Recom-
this test, and that adheres to the glassware after fuel has been
mendations issued by the World Trade Organization Technical
flushed from the system.
Barriers to Trade (TBT) Committee.
3.2.2 filterable insolubles, n—material that is produced in
2. Referenced Documents
the course of stressing distillate fuel under the conditions of
2
this test, and that is capable of being removed from the fuel by
2.1 ASTM Standards:
filtration.
D56Test Method for Flash Point by Tag Closed Cup Tester
D93Test Methods for Flash Point by Pensky-Martens
3.2.3 inherent stability, n—the resistance to change when
Closed Cup Tester
exposed to air, in the absence of other environmental factors
such as water, reactive metal surfaces, and dirt.
3.2.4 storage stability, n—theresistanceoffueltoformation
1
This test method is under the jurisdiction of ASTM Committee D02 on
of degradation products when stored at ambient temperatures.
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.14 on Stability, Cleanliness and Compatibility of Liquid Fuels.
3.2.5 thermal stability, n—theresistanceoffueltoformation
Current edition approved May 1, 2022. Published May 2022. Originally
of degradation products when thermally stressed.
approved in 1999. Last previous edition approved in 2019 as D6468–08 (2019).
DOI: 10.1520/D6468-22.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 4. Summary of Test Method
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
4.1 Two50mLvolumesoffilteredmiddledistillatefuelare
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. aged for 90min or 180min at 150°C in open tubes with air
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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D6468 − 2
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D6468 − 08 (Reapproved 2019) D6468 − 22
Standard Test Method for
1
High Temperature Stability of Middle Distillate Fuels
This standard is issued under the fixed designation D6468; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Scope*
1.1 This test method covers relative stability of middle distillate fuels under high temperature aging conditions with limited air
exposure. This test method is suitable for all No. 1 and No. 2 grades in Specifications D396, D975, D2880, and D3699. It is also
suitable for similar fuels meeting other specifications.
1.2 This test method is not suitable for fuels whose flash point, as determined by Test Methods D56, D93, or D3828, is less than
38 °C. This test method is not suitable for fuels containing residual oil.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3.1 Exception—The maximum vacuum includes inch-pound units in 6.5 and 11.2.
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.
2. Referenced Documents
2
2.1 ASTM Standards:
D56 Test Method for Flash Point by Tag Closed Cup Tester
D93 Test Methods for Flash Point by Pensky-Martens Closed Cup Tester
D396 Specification for Fuel Oils
D975 Specification for Diesel Fuel
D1500 Test Method for ASTM Color of Petroleum Products (ASTM Color Scale)
D2274 Test Method for Oxidation Stability of Distillate Fuel Oil (Accelerated Method)
D2880 Specification for Gas Turbine Fuel Oils
D3699 Specification for Kerosine
D3828 Test Methods for Flash Point by Small Scale Closed Cup Tester
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
1
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.14 on Stability, Cleanliness and Compatibility of Liquid Fuels.
Current edition approved May 1, 2019May 1, 2022. Published July 2019May 2022. Originally approved in 1999. Last previous edition approved in 20132019 as
D6468 – 08 (2013).(2019). DOI: 10.1520/D6468-08R19.10.1520/D6468-22.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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D6468 − 22
D4625 Test Method for Middle Distillate Fuel Storage Stability at 43 °C (110 °F)
D5452 Test Method for Particulate Contamination in Aviation Fuels by Laboratory Filtration
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in this test method, refer to Terminology D4175.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 adherent insolubles—insolubles, n—material that is produced in the course of stressing distillate fuel under the conditions
of this test, and that adheres to the glassware after fuel has been flushed from the system.
3.2.2 filterable insolubles—insolubles, n—material that is produced in the course of stressing distillate fuel under the conditions
of this test, and that is capable of being removed from the fuel by filtration.
3.2.3 inherent stability—stability, n—the resistance to change when exposed to air, but in the absence of other environmental
factors such as water, reactive metal surfaces, and dirt.
3.2.4 storage stability—stability, n—the resistance of fuel to formation of degradation products
...