ASTM D6468-08(2019)

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: Historical
• Publication Date: 30-Apr-2019
• 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

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D6468 − 08 (Reapproved 2019)
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 Oils
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 D4625Test Method for Middle Distillate Fuel Storage
Stability at 43°C (110°F)
standard. No other units of measurement are included in this
standard. D5452Test Method for Particulate Contamination in Avia-
tion Fuels by Laboratory Filtration
1.3.1 Exception—The maximum vacuum includes inch-
pound units in 6.5 and 11.2.
3. Terminology
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3.1 Definitions of Terms Specific to This Standard:
responsibility of the user of this standard to establish appro-
3.1.1 adherent insolubles—material that is produced in the
priate safety, health, and environmental practices and deter-
course of stressing distillate fuel and that adheres to the
mine the applicability of regulatory limitations prior to use.
glassware after fuel has been flushed from the system.
1.5 This international standard was developed in accor-
3.1.2 filterable insolubles—material that is produced in the
dance with internationally recognized principles on standard-
course of stressing distillate fuel and that is capable of being
ization established in the Decision on Principles for the
removed from the fuel by filtration.
Development of International Standards, Guides and Recom-
3.1.3 inherent stability—the resistance to change when ex-
mendations issued by the World Trade Organization Technical
posed to air, but in the absence of other environmental factors
Barriers to Trade (TBT) Committee.
such as water, reactive metal surfaces, and dirt.
2. Referenced Documents
3.1.4 storage stability—the resistance of fuel to formation
2
2.1 ASTM Standards: of degradation products when stored at ambient temperatures.
D56Test Method for Flash Point by Tag Closed Cup Tester
3.1.5 thermal stability—the resistance of fuel to formation
D93Test Methods for Flash Point by Pensky-Martens
of degradation products when thermally stressed.
Closed Cup Tester
4. Summary of Test Method
1
This test method is under the jurisdiction of ASTM Committee D02 on
4.1 Two50mLvolumesoffilteredmiddledistillatefuelare
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
aged for 90min or 180min at 150°C in open tubes with air
Subcommittee D02.14 on Stability, Cleanliness and Compatibility of Liquid Fuels.
exposure.Afteragingandcooling,thefuelsamplesarefiltered
CurrenteditionapprovedMay1,2019.PublishedJuly2019.Originallyapproved
and the average amount of filterable insolubles is estimated by
in 1999. Last previous edition approved in 2013 as D6468–08 (2013). DOI:
10.1520/D6468-08R19.
measuring the light reflectance of the filter pads. The 100%
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
and0%extremesofthereflectanceratingrangearedefinedby
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
an unused filter pad and a commercial black standard, respec-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. tively.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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D6468 − 08 (2019)
3 4
grounding cables is recommended. Such an apparatus and correct
5. Significance and Use
grounding practices are described in Test Method D5452. A
...

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 2013) D6468 − 08 (Reapproved 2019)
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
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.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 safety, health, and healthenvironmental 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 Oils
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
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 of Terms Specific to This Standard:
3.1.1 adherent insolubles—material that is produced in the course of stressing distillate fuel and that adheres to the glassware
after fuel has been flushed from the system.
3.1.2 filterable insolubles—material that is produced in the course of stressing distillate fuel and that is capable of being
removed from the fuel by filtration.
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 Stability, Cleanliness and CleanlinessCompatibility of Liquid Fuels.
Current edition approved Oct. 1, 2013May 1, 2019. Published October 2013July 2019. Originally approved in 1999. Last previous edition approved in 20082013 as
D6468 – 08.D6468 – 08 (2013). DOI: 10.1520/D6468-08R13.10.1520/D6468-08R19.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D6468 − 08 (2019)
3.1.3 inherent stability—the resistance to change when exposed to air, but in the absence of other environmental factors such
as water, reactive metal surfaces, and dirt.
3.1.4 storage stability—the resistance of fuel to formation of degradation products when stored at ambient temperatures.
3.1.5 thermal stability—the resistance of fuel to formation of degradation products when thermally stressed.
4. Summary of Test Method
4.1 Two 50-mL50 mL volumes of filtered middle distillate fuel are aged for 9090 min or 180 min 180 min at 150°C150 °C in
op
...