1、Designation: D 6871 03Standard Specification forNatural (Vegetable Oil) Ester Fluids Used in ElectricalApparatus1This standard is issued under the fixed designation D 6871; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year o
2、f last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 a
3、ndcooling 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 pro
4、duct 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
5、and 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 respe
6、ct.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 thesa
7、fety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory requirements prior to use.2. Referenced Documents2.1 ASTM Standards:D 88 Test Method for Saybolt V
8、iscosity2D 92 Test Method for Flash and Fire Points by ClevelandOpen Cup3D 97 Test Method for Pour Point of Petroleum Products3D 117 Guide for Sampling, Test Methods, and Specifica-tions for Electrical Insulating Oils of Petroleum Origin4D 445 Test Method for Kinematic Viscosity of Transparentand Op
9、aque Liquids (the Calculation of Dynamic Viscos-ity)3D 877 Test Method for Dielectric Breakdown Voltage ofInsulating Liquids Using Disk Electrodes4D 923 Practices for Sampling Electrical Insulating Liquids4D 924 Test Method for Dissipation Factor (or Power Factor)and Relative Permittivity (Dielectri
10、c Constant) of Electri-cal Insulating Liquids4D 974 Test Method for Acid and Base Number by Color-Indicator Titration3D 1275 Test Method for Corrosive Sulfur in ElectricalInsulating Oils4D 1298 Practice for Density, Relative Density (SpecificGravity), or API Gravity of Crude Petroleum and LiquidPetr
11、oleum Products by Hydrometer Method3D 1500 Test Method for ASTM Color of Petroleum Prod-ucts (ASTM Color Scale)3D 1524 Test Method for Visual Examination of Used Elec-trical Insulating Oils of Petroleum Origin in the Field4D 1533 Test Methods for Water in Insulating Liquids byCoulometric Karl Fische
12、r Titration4D 1816 Test Method for Dielectric Breakdown Voltage ofInsulating Oils of Petroleum Origin Using VDE Elec-trodes4D 1903 Test Method for Coefficient of Thermal Expansionof Electrical Insulating Liquids of Petroleum Origin, andAskarels4D 2300 Test Method for Gassing of Insulating LiquidsUnd
13、er Electrical Stress and Ionization (Modified PirelliMethod)4D 2717 Test Method for Thermal Conductivity of Liquids3D 2766 Test Method for Specific Heat of Liquids andSolids3D 2864 Terminology Relating to Electrical Insulating Liq-uids and Gases4D 3300 Test Method for Dielectric Breakdown Voltage of
14、Insulating Oils of Petroleum Origin Under Impulse Con-ditions41This specification is under the jurisdiction of ASTM Committee D27 onElectrical Insulating Liquids and Gases and is the direct responsibility of Subcom-mittee D27.02 on Gases and Synthetic Liquids.Current edition approved July 10, 2003.
15、Published August 2003.2Annual Book of ASTM Standards, Vol 04.04.3Annual Book of ASTM Standards, Vol 05.01.4Annual Book of ASTM Standards, Vol 10.03.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.D 4059 Test Method for Analysis of Po
16、lychlorinated Biphe-nyls in Insulating Liquids by Gas Chromatography42.2 National Fire Protection Association Standard:National Electrical Code Article 450-2353. Terminology3.1 DefinitionsDefinitions of terms related to this speci-fication are given in Terminology D 2864. Vegetable oil naturalester:
17、 vegetable oil containing 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 Test MethodsD 923.4.2 Perform each test in accordance with the
18、ASTM testmethod specified 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 D 117 and Appendixes X2.1-X2.3.6. Keywords6.1 electrical insulating fluid; fire point; fl
19、ammability; insu-lating fluid; natural ester5National 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 D 1500Fire point, min, C 300 D 92Flash point, min, C 275 D 92Pour point,
20、max, C 10 D 97Relative density (specific gravity) 15C/15C, max 0.96 D 1298Viscosity, max, cSt at: D 445 or D 88100C (212F) 1540C (104F) 500C (32F) 500Visual Examination Bright and Clear D 1524Electrical:Dielectric breakdown voltage at 60 HzDisk electrodes, min, kV 30 D 877VDE electrodes, min, kV at:
21、 D 18161 mm (0.04 in.) gap 202 mm (0.08 in.) gap 35Dielectric breakdown voltage, impulse conditions25C, min, kV, needle negative to sphere grounded,1 in. (25.4 mm) gap130 D 3300Dissipation factor (or power factor) at 60 Hz, max, % D 92425C 0.20100C 4.0Gassing tendency, max, l/min 0 D 2300Chemical:Co
22、rrosive sulfur not corrosive D 1275Neutralization number, total acid number, max,mg KOH/g0.06 D 974PCB content, ppm not detectable D 4059Water, max, mg/kg 200 D 1533AAAs stated in Test Methods D 1533 Annex A1 “Alternative Solvent Systems,” alternate reagents may be needed for certain natural ester f
23、ormulations. Consult themanufacturer 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 Methods D 1533 reagents may yield elevated and erratic water content results.D687
24、1032APPENDIXES(Nonmandatory Information)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 D 1903Dielectric Constant, 25C 3.1 to 3.3 D 924Property Typical Val
25、uesASTMTest MethodSpecific Heat, cal/g, 20C 0.45 to 0.60 D 2766Thermal Conductivity,(cal/cmsC)0.00035 to0.00045D 2717X2. SIGNIFICANCE OF PROPERTIES PARTICULAR TO NATURAL ESTER INSULATING OILNOTE X2.1The significance of common electrical insulating fluidproperties not listed here may be found in Guid
26、e D 117.X2.1 Physical PropertiesX2.1.1 Aniline PointThe aniline point of natural esterinsulating fluids vary 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 Interfa
27、cial TensionInterfacial tension performancecriteria are being assessed; 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
28、 esterinsulating fluid is important as an index of the lowest tempera-ture 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 l
29、ow temperatureflow properties.X2.2 Electrical PropertiesX2.2.1 Dissipation 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 usuallyh
30、ave higher dissipation factors than mineral insulating oils,especially 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 th
31、einsulation system life, and to minimize metal corrosion.Reagents for aldehydes 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 timest
32、hat of mineral insulating oil. Comparisons to mineral insulat-ing oil should 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
33、conduction and metal corrosion and to maximize thelife of the insulation 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 ten
34、dto form shorter chain organic acids.X2.3.3 Oxidation Inhibitor ContentThe 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 Oxidati
35、on StabilityOxidation stability require-ments and appropriate test methods 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.ASTM International takes
36、 no position respecting the validity of any patent rights asserted 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 resp
37、onsibility.This standard is subject to revision at any time by 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 addresse
38、d to ASTM International Headquarters. Your comments will receive 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
39、address shown below.This standard is copyrighted by ASTM International, 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).D6871033
