1、Designation: D4006 161Manual of Petroleum Measurement Standards (MPMS), Chapter 10.2Standard Test Method forWater in Crude Oil by Distillation1This standard is issued under the fixed designation D4006; the number immediately following the designation indicates the year oforiginal adoption or, in the
2、 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.This standard has been approved for use by agencies of the U.S. Department of Defense.1NOTESubsecti
3、ons 5.1 and X1.3.3.2 were revised editorially in November 2016.1. Scope*1.1 This test method covers the determination of water incrude oil by distillation.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 doe
4、s 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. For specificwarning statements, see
5、 6.1 and A1.1.2. Referenced Documents2.1 ASTM Standards:2D95 Test Method for Water in Petroleum Products andBituminous Materials by Distillation (API MPMS Chapter10.5)D473 Test Method for Sediment in Crude Oils and Fuel Oilsby the Extraction Method (API MPMS Chapter 10.1)D665 Test Method for Rust-Pr
6、eventing Characteristics ofInhibited Mineral Oil in the Presence of WaterD1796 Test Method for Water and Sediment in Fuel Oils bythe Centrifuge Method (Laboratory Procedure) (APIMPMS Chapter 10.6)D4057 Practice for Manual Sampling of Petroleum andPetroleum Products (API MPMS Chapter 8.1)D4177 Practi
7、ce for Automatic Sampling of Petroleum andPetroleum Products (API MPMS Chapter 8.2)D4928 Test Method for Water in Crude Oils by CoulometricKarl Fischer Titration (API MPMS Chapter 10.9)E123 Specification forApparatus for Determination ofWaterby Distillation2.2 API Standards:MPMS Chapter 8.1 Manual S
8、ampling of Petroleum andPetroleum Products (ASTM Practice D4057)MPMS Chapter 8.2 Automatic Sampling of Petroleum andPetroleum Products (ASTM Practice D4177)MPMS Chapter 10.1 Test Method for Sediment in CrudeOils and Fuel Oils by the Extraction Method (ASTM TestMethod D473)MPMS Chapter 10.4 Determina
9、tion of Water and/or Sedi-ment in Crude Oil by the Centrifuge Method (FieldProcedure)MPMS Chapter 10.5 Test Method for Water in PetroleumProducts and Bituminous Materials by Distillation(ASTM Test Method D95)MPMS Chapter 10.6 Test Method for Water and Sediment inFuel Oils by the Centrifuge Method (L
10、aboratory Proce-dure) (ASTM Test Method D1796)MPMS Chapter 10.9 Test Method for Water in Crude Oils byCoulometric Karl Fischer Titration (ASTM Test MethodD4928)3. Summary of Test Method3.1 The sample is heated under reflux conditions with awater immiscible solvent which co-distills with the water in
11、 the1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and the API Committee onPetroleum Measurement and is the direct responsibility of Subcommittee D02.02/COMQ the joint ASTM-API Committee on Hydrocarbon Measurement forCustody Trans
12、fer (Joint ASTM-API). This test method has been approved by thesponsoring committees and accepted by the Cooperating Societies in accordancewith established procedures.Current edition approved June 1, 2016. Published July 2016. Originally approvedin 1981. Last previous edition approved in 2012 as D4
13、006 11 (2012)1. DOI:10.1520/D4006-16E01.2For 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.*A Summary of Changes
14、 section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1sample. Condensed solvent and water are continuously sepa-rated in a trapthe water settles in the graduated section of thetrap, and the solven
15、t returns to the distillation flask.4. Significance and Use4.1 A knowledge of the water content of crude oil isimportant in the refining, purchase, sale, or transfer of crudeoils.4.2 This test method may not be suitable for crude oils thatcontain alcohols that are soluble in water. In cases where th
16、eimpact on the results may be significant, the user is advised toconsider using another test method, such as Test MethodD4928 (API MPMS Chapter 10.9).5. Apparatus5.1 The preferred apparatus, shown in Fig. 1, consists of aglass distillation flask, a condenser, a graduated glass trap, anda heater. Oth
17、er types of distillation apparatus are specified inSpecification E123. Any of these apparatus will be acceptablefor this test method provided it can be demonstrated that theyoperate within the precision established with the preferredapparatus.5.1.1 Distillation FlaskA 1000 mL round-bottom, glass,dis
18、tillation flask fitted with a 24/40 female taper joint shall beused. This flask receives a 5 mL calibrated, graduated watertrap with 0.05 mL graduations. The trap will be fitted with a400 mm Liebig condenser. A drying tube filled with desiccant(to prevent entrance of atmospheric moisture) is placed
19、on topof the condenser.5.1.2 HeaterAny suitable gas or electric heater that canuniformly distribute heat to the entire lower half of the flaskmay be used. An electric heating mantle is preferred for safetyreasons.5.1.3 The apparatus used in this test will be accepted whensatisfactory results are obt
20、ained by the calibration techniquedescribed in Section 8.6. Solvent6.1 Xylenereagent grade (WarningExtremely flam-mable. Vapor harmful. See AnnexA1.)Asolvent blank will beestablished by placing 400 mL of solvent in the distillationapparatus and testing as outlined in Section 9. The blank willbe dete
21、rmined to the nearest 0.025 mL and used to correct thevolume of water in the trap as in Section 10.6.2 The xylene used in this procedure is generally a mixtureof ortho, meta, and para isomers and may contain some ethylbenzene. The typical characteristics for this reagent are:Color (APHA) not more th
22、an 10Boiling range 137 C to 144 CResidue after evaporation 0.002 %Sulfur compounds (as S) 0.003 %Substances darkened by H2SO4Color pass testWater (H2O) 0.02 %Heavy metals (as Pb) 0.1 ppmCopper (Cu) 0.1 ppmIron (Fe) 0.1 ppmNickel (Ni) 0.1 ppmSilver (Ag) 0.1 ppm7. Sampling, Test Samples, and Test Unit
23、s7.1 Sampling is defined as all steps required to obtain analiquot of the contents of any pipe, tank, or other system and toplace the sample into the laboratory test container.7.1.1 Laboratory SampleOnly representative samples ob-tained as specified in Practice D4057 (API MPMS Chapter 8.1)and Practi
24、ce D4177 (API MPMS Chapter 8.2) shall be used forthis test method.7.1.2 Preparation of Test SamplesThe following samplehandling procedure shall apply in addition to those covered in7.1.1.7.1.2.1 The sample size shall be selected as indicated belowbased on the expected water content of the sample:Exp
25、ected Water Content,weight or volume %Approximate Sample Size,gormL50.1100.0 525.1 50.0 1010.1 25.0 205.1 10.0 501.1 5.0 1000.5 1.0 200less than 0.5 2007.1.2.2 If there is any doubt about the uniformity of themixed sample, determinations should be made on at least threetest portions and the average
26、result reported as the watercontent.7.1.2.3 To determine water on a volume basis, measuremobile liquids in a 5 mL, 10 mL, 20 mL, 50 mL, 100 mL, or200 mL calibrated, graduated cylinder (NBS Class A) depend-ing on the sample size indicated in 7.1.2.1. Take care to pourthe sample slowly into the gradua
27、ted cylinder to avoid entrap-ment of air and to adjust the level as closely as possible to theFIG. 1 Distillation ApparatusD4006 1612appropriate graduation. Carefully pour the contents of thecylinder into the distillation flask and rinse the cylinder fivetimes with portions of xylene equivalent to o
28、ne-fifth of thecapacity of the graduated cylinder and add the rinsings to theflask. Drain the cylinder thoroughly to ensure complete sampletransfer.7.1.2.4 To determine water on a mass basis, weigh a testportion of sample in accordance with 7.1.2.1, pouring thesample directly into the distillation f
29、lask. If a transfer vessel(beaker or cylinder) must be used, rinse it with at least fiveportions of xylene and add the rinsings to the flask.8. Calibration8.1 Calibrate both the trap and the entire assembly prior toinitial use and after any equipment changes as indicated in8.1.1 8.1.3.Additionally,
30、calibrate both the trap and the entireassembly periodically, at a frequency not to exceed yearly.8.1.1 Verify the accuracy of the graduation marks on thetrap by adding 0.05 mL increments of distilled water, at 20 C,from a 5 mL microburet or a precision micro-pipet readable tothe nearest 0.01 mL. If
31、there is a deviation of more than0.050 mL between the water added and water observed, rejectthe trap or recalibrate.8.1.2 Also calibrate the entire apparatus. Put 400 mL of dry(0.02 % water maximum) xylene in the apparatus and test inaccordance with Section 9. When complete, discard the con-tents of
32、 the trap and add 1.00 mL 6 0.01 mL of distilled waterfrom the buret or micro-pipet, at 20 C, directly to thedistillation flask and test in accordance with Section 9. Repeat8.1.2 and add 4.50 mL 6 0.01 mL directly to the flask. Theassembly of the apparatus is satisfactory only if trap readingsare wi
33、thin the tolerances specified here:Limits Capacity Volume of Water Permissible forof Trap at 20 C, Added at 20 C, Recovered WatermL mL at 20 C, mL5.005.001.004.501.00 0.0254.50 0.0258.1.3 A reading outside the limits suggests malfunctioningdue to vapor leaks, too rapid boiling, inaccuracies in gradu
34、a-tions of the trap, or ingress of extraneous moisture. Thesemalfunctions must be eliminated before repeating 8.1.2.9. Procedure9.1 The precision of this test method can be affected bywater droplets adhering to surfaces in the apparatus andtherefore not settling into the water trap to be measured. T
35、ominimize the problem, all apparatus must be chemicallycleaned at least daily to remove surface films and debris whichhinder free drainage of water in the test apparatus. Morefrequent cleaning is recommended if the nature of the samplesbeing run causes persistent contamination.9.1.1 To determine wat
36、er on a volume basis, proceed asindicated in 7.1.2.3. In addition to the xylene added to rinse theoil sample transfer device, add sufficient xylene to the flask tomake the total xylene volume 400 mL.9.1.2 To determine water on a mass basis, proceed asindicated in 7.1.2.4. In addition to the xylene a
37、dded to rinse theoil sample transfer device, add sufficient xylene to the flask tomake the total xylene volume 400 mL.9.2 A magnetic stirrer is the most effective device to reducebumping. Glass beads or other boiling aids, although lesseffective, have been found to be useful.9.3 Assemble the apparat
38、us as shown in Fig. 1, making sureall connections are vapor and liquid-tight. It is recommendedthat glass joints not be greased. Insert a drying tube containingan indicating desiccant into the end of the condenser to preventcondensation of atmospheric moisture inside the condenser.Circulate water, b
39、etween 20 C and 25 C, through the con-denser jacket.9.4 Apply heat to the flask. The type of crude oil beingevaluated can significantly alter the boiling characteristics ofthe crude-solvent mixture. Heat should be applied slowlyduring the initial stages of the distillation (approximately12 hto 1 h)
40、to prevent bumping and possible loss of water from thesystem. (Condensate shall not proceed higher than threequarters of the distance up the condenser inner tube (Point A inFig. 1).) To facilitate condenser wash-down, the condensateshould be held as close as possible to the condenser outlet.After th
41、e initial heating, adjust the rate of boiling so that thecondensate proceeds no more than three quarters of thedistance up the condenser inner tube. Distillate should dis-charge into the trap at the rate of approximately 2 drops to5 drops per second. Continue distillation until no water isvisible in
42、 any part of the apparatus, except in the trap, and thevolume of water in the trap remains constant for at least 5 min.If there is a persistent accumulation of water droplets in thecondenser inner tube, flush with xylene. (A jet spray washingtube, see Fig. 2, or equivalent device is recommended.) Th
43、eaddition of an oil-soluble emulsion breaker at a concentrationof 1000 ppm to the xylene wash helps dislodge the clingingwater drops. After flushing, redistill for at least 5 min (the heatmust be shut off at least 15 min prior to wash-down to preventbumping). After wash-down, apply heat slowly to pr
44、eventbumping. Repeat this procedure until no water is visible in thecondenser and the volume of water in the trap remains constantfor at least 5 min. If this procedure does not dislodge the water,use the TFE-fluorocarbon scraper, pick shown in Fig. 2,orequivalent device to cause the water to run int
45、o the trap.9.5 When the carryover of water is complete, allow the trapand contents to cool to 20 C. Dislodge any drops of wateradhering to the sides of the trap with the TFE-fluorocarbonscraper or pick and transfer them to the water layer. Read thevolume of the water in the trap. The trap is graduat
46、ed in0.05 mL increments, but the volume is estimated to the nearest0.025 mL.10. Calculation10.1 Calculate the water in the sample as follows:Volume% 5A 2 B!C3100 (1)Volume% 5A 2 B!M/D!3100 (2)Mass% 5A 2 B!M3100 (3)D4006 1613where:A = mL of water in trap,B = mL of solvent blank,C = mL of test sample,
47、M = g of test sample, andD = density of sample, g/mL.Volatile water-soluble material, if present, may bemeasured as water.11. Report11.1 Report the result as the water content to the nearest0.025 %, reporting water content of less than 0.025 % as 0 %,and reference this Test Method D4006 (API MPMS Ch
48、apter10.2) as the procedure used.12. Precision and Bias12.1 The precision of this test method, as obtained bystatistical examination of interlaboratory test results in therange from 0.01 % to 1.0 %, is described in 12.1.1 and 12.1.2.12.1.1 RepeatabilityThe difference between successivetest results,
49、obtained by the same operator with the sameapparatus under constant operating conditions on identical testmaterial, would, in the long run, in the normal and correctoperation of the test method, exceed the following value inonly one case in twenty:From 0.0 % to 0.1 % water, see Fig. 3.Greater than 0.1 % water, repeatability is constant at 0.08.12.1.2 ReproducibilityThe difference between the twosingle and independent test results obtained by differentoperators working in different laboratories on identical testmaterial, would, in the long
