ASTM D2440-13

Standard Test Method for Oxidation Stability of Mineral Insulating Oil

SIGNIFICANCE AND USE
4.1 The oxidation stability test of mineral transformer oils is a method for assessing the amount of sludge and acid products formed in a transformer oil when the oil is tested under prescribed conditions. Good oxidation stability is necessary in order to maximize the service life of the oil by minimizing the formation of sludge and acid. Oils that meet the requirements specified for this test in Specification D3487 tend to minimize electrical conduction, ensure acceptable heat transfer, and preserve system life. There is no proven correlation between performance in this test and performance in service, since the test does not model the whole insulation system (oil, paper, enamel, wire). However, the test can be used as a control test for evaluating oxidation inhibitors and to check the consistency of oxidation stability of production oils.
SCOPE
1.1 This test method determines the resistance of mineral transformer oils to oxidation under prescribed accelerated aging conditions. Oxidation stability is measured by the propensity of oils to form sludge and acid products during oxidation. This test method is applicable to new oils, both uninhibited and inhibited, but is not well defined for used or reclaimed oils. Note 1—A shorter duration oxidation test for evaluation of inhibited oils is available in Test Method D2112.Note 2—For those interested in the measurement of volatile acidity, reference is made to IEC Method 61125. 2  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Jan-2013
• ICS: 29.040.10 - Insulating oils
• Technical Committee: D27 - Electrical Insulating Liquids and Gases
• Drafting Committee: D27.06 - Chemical Test

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D2440 − 13
Standard Test Method for
1
Oxidation Stability of Mineral Insulating Oil
This standard is issued under the fixed designation D2440; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope D2272 Test Method for Oxidation Stability of Steam Tur-
bine Oils by Rotating Pressure Vessel
1.1 This test method determines the resistance of mineral
D3487 Specification for Mineral Insulating Oil Used in
transformer oils to oxidation under prescribed accelerated
Electrical Apparatus
aging conditions. Oxidation stability is measured by the
propensity of oils to form sludge and acid products during
2.2 IEC Publication:
oxidation. This test method is applicable to new oils, both
IEC 61125: 1992 Unused Hydrocarbon–Based Insulating
uninhibited and inhibited, but is not well defined for used or
Liquids—Test Methods for Evaluating the Oxidation Sta-
4
reclaimed oils.
bility
NOTE 1—A shorter duration oxidation test for evaluation of inhibited
3. Summary of Test Method
oils is available in Test Method D2112.
NOTE 2—For those interested in the measurement of volatile acidity,
2
3.1 Atest specimen of mineral transformer oil is oxidized at
reference is made to IEC Method 61125.
a bath temperature of 110°C, in the presence of a copper
1.2 The values stated in SI units are to be regarded as
catalyst coil, by bubbling oxygen through duplicate test speci-
standard. No other units of measurement are included in this
mens for 72 and 164 h, respectively. The oil is evaluated at the
standard.
end of each aging period by measuring the amount of sludge
1.3 This standard does not purport to address all of the
and acid formed. The test specimen is diluted with n-heptane
safety concerns, if any, associated with its use. It is the
and the solution filtered to remove the sludge. The sludge is
responsibility of the user of this standard to establish appro-
dried and weighed. The sludge-free solution is titrated at room
priate safety and health practices and determine the applica-
temperature with standard alcoholic base to the end point
bility of regulatory limitations prior to use.
indicated by the color change (green-brown) of the added
p-naphthol-benzein solution.
2. Referenced Documents
3
2.1 ASTM Standards:
4. Significance and Use
B1 Specification for Hard-Drawn Copper Wire
4.1 Theoxidationstabilitytestofmineraltransformeroilsis
D664 Test Method for Acid Number of Petroleum Products
a method for assessing the amount of sludge and acid products
by Potentiometric Titration
formed in a transformer oil when the oil is tested under
D974 Test Method for Acid and Base Number by Color-
prescribed conditions. Good oxidation stability is necessary in
Indicator Titration
order to maximize the service life of the oil by minimizing the
D2112 Test Method for Oxidation Stability of Inhibited
formation of sludge and acid. Oils that meet the requirements
Mineral Insulating Oil by Pressure Vessel
specified for this test in Specification D3487 tend to minimize
electrical conduction, ensure acceptable heat transfer, and
1
This test method is under the jurisdiction of ASTM Committee D27 on
preserve system life. There is no proven correlation between
Electrical Insulating Liquids and Gasesand is the direct responsibility of Subcom-
performance in this test and performance in service, since the
mittee D27.06 on Chemical Test.
test does not model the whole insulation system (oil, paper,
Current edition approved Feb. 1, 2013. Published March 2013. Originally
approved in 1965 as D2440 – 65 T. Last previous edition approved in 2004 as
enamel, wire). However, the test can be used as a control test
D2440 – 99(2004). DOI: 10.1520/D2440-13.
forevaluatingoxidationinhibitorsandtochecktheconsistency
2
Supporting data have been filed at ASTM International Headquarters and may
of oxidation stability of production oils.
beobtainedbyrequestingResearchReportRR:D27-1001.ContactASTMCustomer
Service at [e-mail].
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
4
Standards volume information, refer to the standard’s Document Summary page on International Electrotechnical Commission. Available from American National
the ASTM website. Standards Institute, 25 W. 43rd St., 4th Floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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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: D2440 − 99 (Reapproved 2004) D2440 − 13
Standard Test Method for
1
Oxidation Stability of Mineral Insulating Oil
This standard is issued under the fixed designation D2440; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope
1.1 This test method determines the resistance of mineral transformer oils to oxidation under prescribed accelerated aging
conditions. Oxidation stability is measured by the propensity of oils to form sludge and acid products during oxidation. This test
method is applicable to new oils, both uninhibited and inhibited, but is not well defined for used or reclaimed oils.
NOTE 1—A shorter duration oxidation test for evaluation of inhibited oils is available in Test Method D2112.
2
NOTE 2—For those interested in the measurement of volatile acidity, reference is made to the work of IEC Subcommittee 10A. IEC Method 61125.
1.2 The values stated in metricSI units are to be regarded as the standard. No other units of measurement are included in this
standard.
1.3 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 and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
3
2.1 ASTM Standards:
B1 Specification for Hard-Drawn Copper Wire
D664 Test Method for Acid Number of Petroleum Products by Potentiometric Titration
D974 Test Method for Acid and Base Number by Color-Indicator Titration
D2112 Test Method for Oxidation Stability of Inhibited Mineral Insulating Oil by Pressure Vessel
D2272 Test Method for Oxidation Stability of Steam Turbine Oils by Rotating Pressure Vessel
D3487 Specification for Mineral Insulating Oil Used in Electrical Apparatus
2.2 IEC Publication:
CEI/IFCIEC 61125: 1992 Unused Hydrocarbon–Based Insulating Liquids—Test Methods for Evaluating the Oxidation
4
Stability
3. Summary of Test Method
3.1 A test specimen of mineral transformer oil is oxidized at a bath temperature of 110°C, in the presence of a copper catalyst
coil, by bubbling oxygen through duplicate test specimens for 72 and 164 h, respectively. The oil is evaluated at the end of each
aging period by measuring the amount of sludge and acid formed. The test specimen is diluted with n-heptane and the solution
filtered to remove the sludge. The sludge is dried and weighed. The sludge-free solution is titrated at room temperature with
standard alcoholic base to the end point indicated by the color change (green-brown) of the added p-naphthol-benzein solution.
4. Significance and Use
4.1 The oxidation stability test of mineral transformer oils is a method for assessing the amount of sludge and acid products
formed in a transformer oil when the oil is tested under prescribed conditions. Good oxidation stability is necessary in order to
1
This test method is under the jurisdiction of ASTM Committee D27 on Electrical Insulating Liquids and Gasesand is the direct responsibility of Subcommittee D27.06
on Chemical Test.
Current edition approved Oct. 1, 2004Feb. 1, 2013. Published November 2004March 2013. Originally approved in 1965 as D2440 – 65 T. Last previous edition approved
in 19992004 as D2440 – 99.D2440 – 99(2004). DOI: 10.1520/D2440-99R04.10.1520/D2440-13.
2
ASTM Research Report No. Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:D27-1001,
available from ASTM Headquarters, 100 Barr Harbor Drive, West Conshohocken, PA 19428. Contact ASTM Customer Service at [e-mail].
3
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.
4
International Electrotechnical Commission. Available from American National Standards Institute, 25 W. 43rd St., 4th Floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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D2440 − 13
maximize the service life of the oil by
...