ASTM D831/D831M-12(2020)

Standard Test Method for Gas Content of Cable and Capacitor Oils

SIGNIFICANCE AND USE
4.1 The gas content of cable and capacitor oils is considered to be important, since the evolution of gas in the form of bubbles can have an adverse effect on the insulating properties of these fluids. It is customary to degas these oils prior to use, and this test method provides a means of determining the gas content before and after degassing.
SCOPE
1.1 This test method covers the determination of the gas content of electrical insulating oils of low and medium viscosities in the general range up to 190 mm2/s at 104°F [40°C], such as are used in capacitors and paper-insulated electric cables and cable systems of the oil-filled type. The determination of gas content is desirable for any insulating oil having these properties and intended for use in a degassed state.
Note 1: For testing insulating oils with viscosities of 19 mm2/s or below at 40°C, see Test Method D2945.  
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 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-Nov-2020
• ICS: 29.040.10 - Insulating oils
• Technical Committee: D27 - Electrical Insulating Liquids and Gases
• Drafting Committee: D27.03 - Analytical Tests

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: D831/D831M − 12 (Reapproved 2020)
Standard Test Method for
1
Gas Content of Cable and Capacitor Oils
This standard is issued under the fixed designation D831/D831M; 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.
2
1. Scope D2945Test Method for Gas Content of Insulating Oils
2
(Withdrawn 2012)
1.1 This test method covers the determination of the gas
content of electrical insulating oils of low and medium
3. Summary of Test Method
2
viscosities in the general range up to 190 mm /s at 104°F
3.1 This test method consists essentially of feeding the oil
[40°C], such as are used in capacitors and paper-insulated
into an evacuated chamber in such a manner that the oil is
electric cables and cable systems of the oil-filled type. The
thoroughlyexposedtothevacuum,allowingfreeescapeofany
determination of gas content is desirable for any insulating oil
dissolvedgas.Fromthevolumeofoiladmittedtothechamber,
having these properties and intended for use in a degassed
the temperature, the pressure produced, and volume occupied
state.
by the released gas, the gas volume under standard conditions
2
NOTE 1—For testing insulating oils with viscosities of 19 mm /s or
of pressure and temperature may be calculated as a percentage
below at 40°C, see Test Method D2945.
by volume of oil.
1.2 The values stated in either SI units or inch-pound units
4. Significance and Use
are to be regarded separately as standard. The values stated in
each system are not necessarily exact equivalents; therefore, to 4.1 Thegascontentofcableandcapacitoroilsisconsidered
ensure conformance with the standard, each system shall be to be important, since the evolution of gas in the form of
bubbles can have an adverse effect on the insulating properties
used independently of the other, and values from the two
systems shall not be combined. of these fluids. It is customary to degas these oils prior to use,
and this test method provides a means of determining the gas
1.3 This standard does not purport to address all of the
content before and after degassing.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
5. Apparatus (see Fig. 1)
priate safety, health, and environmental practices and deter-
5.1 Degassing Chamber—Degassing chamber, A, made of
mine the applicability of regulatory limitations prior to use.
4
heat-resistantglass (withcalibratedoilwellatbottom),having
1.4 This international standard was developed in accor-
afixedtotalspacevolumeofabout175to300mL.Theoilwell
dance with internationally recognized principles on standard-
shall have a maximum capacity of 50 mL and shall be
ization established in the Decision on Principles for the
calibrated in 0.2-mL divisions.
Development of International Standards, Guides and Recom-
5.2 Stopcocks—Glass stopcocks, B and C, which shall have
mendations issued by the World Trade Organization Technical
large-diameter barrels and a mirror finish to ensure against
Barriers to Trade (TBT) Committee.
5
leakage. Use stopcock grease on all stopcocks and ground-
glass joints.
2. Referenced Documents
2.1 ASTM Standards: 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.
1 2
This test method is under the jurisdiction of ASTM Committee D27 on The last approved version of this historical standard is referenced on
Electrical Insulating Liquids and Gases and is the direct responsibility of Subcom- www.astm.org.
4
mittee D27.03 on Analytical Tests. Borosilicate glass has been found to be satisfactory for this purpose.
5
Current edition approved Dec. 1, 2020. Published December 2020. Originally AstopcockgreaseequivalenttoNo.15521.Areadilyavailablevacuumsealing
approved in 1945. Last previous edition approved in 2012 as D831–12. DOI: compound. Dow Corning grease #1597418, has been found to be satisfactory for
10.1520/D0831_D0831M-12R20. this use.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D831/D831M − 12 (2020)
thermocouple fastened to the oil chamber at the 25-mL mark
and suitably shielded to eliminate radiation errors.
6. Sampling
6.1 Whenconvenient,connectthedegassingcham
...