1、Designation: D6871 17Standard Specification forNatural (Vegetable Oil) Ester Fluids Used in ElectricalApparatus1This standard is issued under the fixed designation D6871; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers a high fire point natural veg-etable oil ester insulating fluid for use as a dielectric andc
3、ooling medium in new and existing power and distributionelectrical apparatus such as transformers and attendant equip-ment.1.2 Natural vegetable oil ester insulating fluid differs fromconventional mineral oil and other high fire point (or “less-flammable”) fluids in that it is an agricultural produc
4、t derivedfrom vegetable oils rather than refined from petroleum basestocks or synthesized from organic precursors.1.3 This specification is intended to define a natural veg-etable oil ester electrical insulating fluid that is compatible withtypical materials of construction of existing apparatus and
5、 willsatisfactorily maintain its functional characteristic in thisapplication. The material described in this specification maynot be miscible with some synthetic electrical insulatingliquids. The user should contact the manufacturer of the naturalester insulating fluid for guidance in this respect.
6、1.4 This specification applies only to new insulating fluid asreceived prior to any processing. The user should contact themanufacturer of the equipment or fluid if questions of recom-mended characteristics or maintenance procedures arise.1.5 This standard does not purport to address all of thesafet
7、y concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accor-dance
8、 with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Stand
9、ards:2D88 Test Method for Saybolt ViscosityD92 Test Method for Flash and Fire Points by ClevelandOpen Cup TesterD97 Test Method for Pour Point of Petroleum ProductsD117 Guide for Sampling, Test Methods, and Specificationsfor Electrical Insulating Oils of Petroleum OriginD445 Test Method for Kinemati
10、c Viscosity of Transparentand Opaque Liquids (and Calculation of Dynamic Viscos-ity)D877 Test Method for Dielectric Breakdown Voltage ofInsulating Liquids Using Disk ElectrodesD923 Practices for Sampling Electrical Insulating LiquidsD924 Test Method for Dissipation Factor (or Power Factor)and Relati
11、ve Permittivity (Dielectric Constant) of Electri-cal Insulating LiquidsD974 Test Method for Acid and Base Number by Color-Indicator TitrationD1275 Test Method for Corrosive Sulfur in Electrical Insu-lating LiquidsD1298 Test Method for Density, Relative Density, or APIGravity of Crude Petroleum and L
12、iquid Petroleum Prod-ucts by Hydrometer MethodD1500 Test Method for ASTM Color of Petroleum Products(ASTM Color Scale)D1524 Test Method for Visual Examination of Used Elec-trical Insulating Liquids in the FieldD1533 Test Method for Water in Insulating Liquids byCoulometric Karl Fischer TitrationD181
13、6 Test Method for Dielectric Breakdown Voltage ofInsulating Liquids Using VDE ElectrodesD1903 Practice for Determining the Coefficient of ThermalExpansion of Electrical Insulating Liquids of PetroleumOrigin, and AskarelsD2300 Test Method for Gassing of Electrical InsulatingLiquids Under Electrical S
14、tress and Ionization (ModifiedPirelli Method)1This specification is under the jurisdiction of ASTM Committee D27 onElectrical Insulating Liquids and Gasesand is the direct responsibility of Subcom-mittee D27.02 on Gases and Non-Mineral Oil Liquids.Current edition approved Nov. 1, 2017. Published Dec
15、ember 2017. Originallyapproved in 2003. Last previous edition approved in 2008 as D6871 03 (2008)which was withdrawn January 2017 and reinstated in November 2017. DOI:10.1520/D6871-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm
16、.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with int
17、ernationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1D2717 Test Method for Thermal Conductivity of
18、LiquidsD2766 Test Method for Specific Heat of Liquids and SolidsD2864 Terminology Relating to Electrical Insulating Liq-uids and GasesD3300 Test Method for Dielectric Breakdown Voltage ofInsulating Oils of Petroleum Origin Under Impulse Con-ditionsD4059 Test Method for Analysis of Polychlorinated Bi
19、phe-nyls in Insulating Liquids by Gas Chromatography2.2 National Fire Protection Association Standard:National Electrical Code Article 450-2333. Terminology3.1 DefinitionsDefinitions of terms related to this specifi-cation are given in Terminology D2864. Vegetable oil naturalester: vegetable oil con
20、taining ester linkages, typically triglyc-erides. Most often obtained from seed crops (a “natural” sourceof esters, as opposed to synthesized esters).4. Sampling and Testing4.1 Take all fluid samples in accordance with PracticesD923.4.2 Perform each test in accordance with the ASTM testmethod specif
21、ied in Table 1.5. Property Requirements5.1 Natural ester insulating fluid, as received, shall conformto the requirements of Table 1. The significance of theseproperties is covered in Guide D117 and Appendixes X2.1 X2.3.6. Keywords6.1 electrical insulating fluid; fire point; flammability; insu-lating
22、 fluid; natural ester3National Electrical Code, NFPA 70, National Fire Protection Association Inc.TABLE 1 As-Received New Fluid Property RequirementsProperty Limit ASTM Test MethodPhysical:Color, max 1.0 D1500Fire point, min, C 300 D92Flash point, min, C 275 D92Pour point, max, C 10 D97Relative dens
23、ity (specific gravity) 15 C 15 C, max 0.96 D1298Viscosity, max, cSt at: D445 or D88100 C (212 F) 1540 C (104 F) 500 C (32 F) 500Visual Examination Bright and Clear D1524Electrical:Dielectric breakdown voltage at 60 HzDisk electrodes, min, kV 30 D877VDE electrodes, min, kV at: D18161 mm (0.04 in.) ga
24、p 202 mm (0.08 in.) gap 35Dielectric breakdown voltage, impulse conditions25 C, min, kV, needle negative to sphere grounded,1 in. (25.4 mm) gap130 D3300Dissipation factor (or power factor) at 60 Hz, max, % D92425 C 0.20100 C 4.0Gassing tendency, max, l/min 0 D2300Chemical:Corrosive sulfur not corros
25、ive D1275Neutralization number, total acid number, max,mg KOH/g0.06 D974PCB content, ppm not detectable D4059Water, max, mg/kg 200 D1533AAAs stated in Test Method D1533 Annex A1 “Alternative Solvent Systems,” alternate reagents may be needed for certain natural ester formulations. Consult themanufac
26、turer for recommendations. Reagents for aldehydes and ketones (such as Coulomat AK and CG-K) should be used if the additives are unknown. When alternatereagents are needed, using the Test Method D1533 reagents may yield elevated and erratic water content results.D6871 172APPENDIXES(Nonmandatory Info
27、rmation)X1. SUPPLEMENTARY DESIGN INFORMATIONX1.1 The following values are typical for natural esterinsulating fluids.Property Typical ValuesASTMTest MethodCoefficient of Expansion, C-10.0007 to 0.0008 D1903Dielectric Constant, 25 C 3.1 to 3.3 D924Specific Heat, cal/g, 20 C 0.45 to 0.60 D2766Thermal
28、Conductivity,(cal/cmsC)0.00035 to0.00045D2717X2. SIGNIFICANCE OF PROPERTIES PARTICULAR TO NATURAL ESTER INSULATING OILNOTE X2.1The significance of common electrical insulating fluidproperties not listed here may be found in Guide D117.X2.1 Physical PropertiesX2.1.1 Aniline PointThe aniline point of
29、natural esterinsulating fluids varies dramatically from source to source. Thevariation is such that the aniline point may not be a dependableindicator of solvency of some materials in natural esterinsulating fluids.X2.1.2 Interfacial TensionInterfacial tension performancecriteria are being assessed;
30、 therefore, requirements have notbeen established. Interfacial tension of new natural esterinsulating fluids, typically in the 26 to 30 mN/m range, is lowerthan that of new mineral oil.X2.1.3 Pour PointThe pour point of a natural esterinsulating fluid is important as an index of the lowest tempera-t
31、ure to which the material may be cooled without seriouslylimiting the degree of circulation. Some natural ester fluids aresensitive to prolonged storage at low temperatures, and theirpour points may not adequately predict their low temperatureflow properties.X2.2 Electrical PropertiesX2.2.1 Dissipat
32、ion FactorDissipation factor (power fac-tor) is a measure of the dielectric losses in fluid. A lowdissipation factor indicates low dielectric losses and a low levelof soluble contaminants. Natural ester insulating fluids usuallyhave higher dissipation factors than mineral insulating oils,especially
33、at elevated temperatures.X2.3 Chemical PropertiesX2.3.1 Water ContentA low water content of natural esterinsulating fluid is necessary to achieve adequate electricalstrength and low dielectric loss characteristics, to maximize theinsulation system life, and to minimize metal corrosion.Reagents for a
34、ldehydes and ketones should be used. Thestandard reagents for mineral oil may yield both elevated anderratic results. The amount of water required to saturate naturalester insulating fluid at room temperature is roughly 20 timesthat of mineral insulating oil. Comparisons to mineral insulat-ing oil s
35、hould be made on a percent saturation (relativesaturation) basis rather than using absolute water content.X2.3.2 Neutralization NumberA low total acid content ofa natural ester insulating fluid is necessary to minimizeelectrical conduction and metal corrosion and to maximize thelife of the insulatio
36、n system. The neutralization numberstypical of natural ester insulating fluids are usually higher thanthose of mineral insulating oils. Natural ester insulating oilstend to form long-chain fatty acids. Mineral insulating oils tendto form shorter chain organic acids.X2.3.3 Oxidation Inhibitor Content
37、The oxidation inhibi-tor additives that may be present in natural ester insulatingfluids vary by manufacturer. The manufacturer should becontacted to obtain information and recommended analysismethods for additives.X2.3.4 Oxidation StabilityOxidation stability require-ments and appropriate test meth
38、ods for natural ester insulatingfluids have not been established. Oxidation stability perfor-mance criteria are being assessed, and may differ for sealedsystems, conservators, and free-breathing apparatus.D6871 173ASTM International takes no position respecting the validity of any patent rights asse
39、rted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by
40、 the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will recei
41、ve careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM Inter
42、national, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 174
