ASTM_D_1903_-_08.pdf

Designation:D190308Standard Practice forDetermining the Coefficient of Thermal Expansion ofElectrical Insulating Liquids of Petroleum Origin,andAskarels1This standard is issued under the fixed designation D1903;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of 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 practice covers the determination of the coef-ficientof thermal expansion of electrical insulating liquids of petro-leum origin,and askarels,containing PCBs(polychlorinatedbiphenyls),when used as an insulating or cooling medium,orboth,in cables,transformers,oil circuit breakers,capacitors,orsimilar apparatus.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety 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 limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D941D1250 Guide for Use of the Petroleum Measurement TablesD1298 Test Method for Density,Relative Density(SpecificGravity),or API Gravity of Crude Petroleum and LiquidPetroleum Products by Hydrometer MethodD1810 Test Method for Specific Gravity of Askarels(Dis-continued 2001)(Withdrawn 2001)33.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 coeffcient of thermal expansion of a liquid,nthechange in volume per unit volume per degree change intemperature.It is commonly stated as the average coefficientover a given temperature range.4.Significance and Use4.1 Knowledge of the coefficient of thermal expansion of aliquid is essential to compute the required size of a container toaccommodate a volume of liquid over the full temperaturerange to which it will be subjected.It is also used to computethe volume of void space that would exist in an inelastic devicefilled with the liquid after the liquid has cooled to a lowertemperature.5.Procedure for Liquids of Petroleum Origin5.1 The coefficient of thermal expansion used in GuideD1250,is 0.00040/F for the temperature range from 17.7 to65.5C(0 to 150F),and petroleum oils ranging from 15.0 to34.9API gravity or 0.9659 to 0.8504 relative density(specificgravity).In the preparation of these tables for relative density(specific gravity)values above 0.600,it has been assumed forpurposes of standardization that all crude petroleum andpetroleum products have uniform coefficients of expansion inthe same temperature ranges.When the required accuracy ofresults falls within these assumptions,this value for coefficientof expansion may be used.5.2 If closer approximation than that indicated in 5.1 isrequired,the coefficient of thermal expansion may be calcu-lated by determining observed relative densities(specificgravities).Determine the relative densities at any two tempera-tures below 90C(194F)and not less than 5C(9F),normore than 14C(25F)degrees apart by Practice D1298.Thedifference in the observed relative densities at the two tem-peratures divided by the product of the relative density at thelower temperature and the difference in the two temperaturesmay be used as the average coefficient of expansion for theobserved temperature range.6.Procedure for Askarels6.1 Determine the relative density(specific gravity)of theaskarel at any two convenient temperatures below 90C1This practice is under the jurisdiction of ASTM Committee D27 on ElectricalInsulating Liquids and Gasesand is the direct responsibility of SubcommitteeD27.07 on Physical Test.Current edition approved Nov.1,2008.Published December 2008.Originallyapproved in 1961.Last previous edition approved in 2003 as D1903 03.DOI:10.1520/D1903-08.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1(194F)and not less than 14C(25F)apart by Test MethodD1810.The difference in the observed relative densities at thetwo temperatures divided by the product of the relative densityat the lower temperature and the difference in the two tempera-tures may be used as the average coefficient of expansion forthe observed temperature range.6.2 If suitably calibrated hydrometers for determining therelative density of an askarel are not available,Test MethodD941 may be used.7.Calculation7.1 Calculate the coefficient of thermal expansion as fol-lows:Coefficient of thermal expansion5S 2 S1!/ST12 T!where:S=relati