ASTM_D_6470_-_99_2020.pdf

Designation:D647099(Reapproved 2020)Standard Test Method forSalt in Crude Oils(Potentiometric Method)1This standard is issued under the fixed designation D6470;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 test method covers the determination of salt incrude oils.For the purpose of this test method,salt is expressedas%(m/m)NaCl(sodium chloride)and covers the range from0.0005%to 0.15%(m/m).1.2 The limit of detection is 0.0002%(m/m)for salt(asNaCl).1.3 The test method is applicable to nearly all of the heavierpetroleum products,such as crude oils,residues,and fuel oils.It may also be applied to used turbine oil and marine diesel fuelto estimate seawater contamination.Water extractable salts,originating from additives present in oils,are codetermined.1.4 The values stated in SI units are to be regarded as thestandard.1.5 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,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 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 Standards:2D329 Specification for AcetoneD770 Specification for Isopropyl AlcoholD843 Specification for Nitration Grade XyleneD1193 Specification for Reagent WaterD4006 Test Method for Water in Crude Oil by DistillationD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD4377 Test Method for Water in Crude Oils by Potentiomet-ric Karl Fischer Titration(Withdrawn 2020)3D4928 Test Method for Water in Crude Oils by CoulometricKarl Fischer TitrationE200 Practice for Preparation,Standardization,and Storageof Standard and Reagent Solutions for Chemical Analysis3.Summary of Test Method3.1 After homogenizing the crude oil with a mixer,aweighed aliquot is dissolved in xylene at 65 C and extractedwith specified volumes of alcohol,acetone,and water in anelectrically heated extraction apparatus.A portion of theaqueous extract is analyzed for total halides by potentiometrictitration.4.Significance and Use4.1 A knowledge of water extractable inorganic halides inoil is important when deciding whether or not the oils needdesalting.Excessive halide,especially in crude oil,frequentlyresults in higher corrosion rates in refining units.5.Apparatus5.1 Extraction Apparatus,made of borosilicate glass,con-forming to the dimensions given in Fig.1,and consisting of thefollowing component parts:5.1.1 Boiling Flask,500 mL capacity.5.1.2 Hopkins Reflux Condenser,having a vapor outletconnected by a rubber tube to an outside vent or to a suctionhood.5.1.3 Thistle Tube,approximately 70 mL capacity,with aline to indicate approximately the 50 mL level.5.1.4 Heating Tube,containing a chimney for increasingconvection in the liquid.5.1.5 Heating Coil,250 W,consisting of a suitable gage ofNichrome wire.5.1.6 Rheostat,of suitable resistance and capacity,forregulating the heater.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.03 on Elemental Analysis.Current edition approved May 1,2020.Published June 2020.Originallyapproved in 1999.Last previous edition approved in 2015 as D6470 99(2015).DOI:10.1520/D6470-99R20.2For 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 StatesThis international standard was developed in accordance with internationally 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.5.2 Safety Shield,colorless safety glass,or equivalent,to bemounted in front of the extraction apparatus(see 5.1).5.3 Sampling Tube,glass,length approximately 600 mm,I.D.approximately 5 mm,with a bulb having a volume of100 mL,or more,and drawn out at one end to an opening ofinside diameter(I.D.)2 mm to 3 mm.