1、Designation: D 4007 08Designation: Manual of Petroleum Measurement Standards (MPMS), Chapter 10.3An American National StandardStandard Test Method forWater and Sediment in Crude Oil by the Centrifuge Method(Laboratory Procedure)1This standard is issued under the fixed designation D 4007; the number
2、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 (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.
3、1 This test method describes the laboratory determinationof water and sediment in crude oils by means of the centrifugeprocedure. This centrifuge method for determining water andsediment in crude oils is not entirely satisfactory. The amountof water detected is almost always lower than the actual wa
4、tercontent. When a highly accurate value is required, the revisedprocedures for water by distillation, Test Method D 4006 (APIMPMS Chapter 10.2) (Note 1), and sediment by extraction,Test Method D 473 (API MPMS Chapter 10.1), shall be used.NOTE 1Test Method D 4006 (API MPMS Chapter 10.2) has beendete
5、rmined to be the preferred and most accurate method for thedetermination of water.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if any, associated w
6、ith 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. Specific warningstatements appear in 6.1, 8.3, and A1.5.4.2. Referenced Documents2.1 ASTM Standards:2D95 Te
7、st Method for Water in Petroleum Products andBituminous Materials by Distillation (API MPMS Chapter10.5)D 473 Test Method for Sediment in Crude Oils and FuelOils by the Extraction Method (API MPMS Chapter 10.1)D 665 Test Method for Rust-Preventing Characteristics ofInhibited Mineral Oil in the Prese
8、nce of WaterD 1796 Test Method forWater and Sediment in Fuel Oils bythe Centrifuge Method (Laboratory Procedure) (APIMPMS Chapter 10.6)D 4006 Test Method for Water in Crude Oil by Distillation(API MPMS Chapter 10.2)D 4057 Practice for Manual Sampling of Petroleum andPetroleum Products (API MPMS Chap
9、ter 8.1)D 4177 Practice for Automatic Sampling of Petroleum andPetroleum Products (API MPMS Chapter 8.2)D 5854 Practice for Mixing and Handling of LiquidSamples of Petroleum and Petroleum Products (APIMPMS Chapter 8.3)E 969 Specification for Glass Volumetric (Transfer) Pipets2.2 API Standards:3MPMS
10、Chapter 8.1 Manual Sampling of Petroleum andPetroleum Products (ASTM Practice D 4057)MPMS Chapter 8.2 Automatic Sampling of Petroleum andPetroleum Products (ASTM Practice D 4177)MPMS Chapter 8.3 Mixing and Handling of Liquid Samplesof Petroleum and Petroleum Products (ASTM PracticeD 5854)MPMS Chapte
11、r 10.1 Determination of Sediment in CrudeOils and Fuel Oils by the Extraction Method (ASTM TestMethod D 473)MPMS Chapter 10.2 Determination of Water in Crude Oilby Distillation (ASTM Test Method D 4006)MPMS Chapter 10.4 Determination of Sediment and Waterin Crude Oil by the Centrifuge Method (Field
12、Procedure)MPMS Chapter 10.5 Determination of Water in PetroleumProducts and Bituminous Materials by Distillation(ASTM Test Method D95)MPMS Chapter 10.6 Determination of Water and Sedimentin Fuel Oils by the Centrifuge Method (Laboratory Pro-cedures) (ASTM Test Method D 1796)1This test method is unde
13、r the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and the API Committee on Petroleum Measure-ment, and is the direct responsibility of Subcommittee D02.02/COMQ, the jointASTM-API Committee on Static Petroleum Measurement.Current edition approved March 1, 2008. Published Ap
14、ril 2008. Originallyapproved in 1981. Last previous edition approved in 2006 as D 400702(2006).This test method has been approved by the sponsoring committees and acceptedby the Cooperating Societies in accordance with established procedures. Thismethod was issued as a joint ASTM-API-IP standard in
15、1981.2For 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.3Available from American Petroleum Institute (API), 1220
16、 L. St., NW, Wash-ington, DC 20005-4070, www.api.org.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.2.3 IP Standard:4Methods Book, Appendix B Specification for Methyl
17、ben-zenes (Toluenes)2.4 ISO Standard:5ISO 5272:1979 Toluene for Industrial UseSpecifications3. Summary of Test Method3.1 Equal volumes of crude oil and water-saturated tolueneare placed into a cone-shaped centrifuge tube. After centrifu-gation, the volume of the higher density water and sedimentlaye
18、r at the bottom of the tube is read.4. Significance and Use4.1 The water and sediment content of crude oil is signifi-cant because it can cause corrosion of equipment and problemsin processing.Adetermination of water and sediment content isrequired to measure accurately net volumes of actual oil ins
19、ales, taxation, exchanges, and custody transfers. It is notanticipated that this test method, which is written with adedicated laboratory facility in mind, is likely to be used infield test rooms or sample rooms due to safety concerns forproper ventilation and handling.5. Apparatus5.1 Centrifuge:5.1
20、.1 A centrifuge capable of spinning two or more filledcone-shaped, 203-mm (8-in.) centrifuge tubes at a speed thatcan be controlled to give a relative centrifugal force (rcf) of aminimum of 600 at the tip of the tubes shall be used (see 5.1.6).5.1.2 The revolving head, trunnion rings, and trunnion c
21、ups,including the cushions, shall be soundly constructed to with-stand the maximum centrifugal force capable of being deliv-ered by the power source. The trunnion cups and cushions shallfirmly support the tubes when the centrifuge is in motion. Thecentrifuge shall be enclosed by a metal shield or ca
22、se strongenough to eliminate danger if any breakage occurs.5.1.3 The centrifuge shall be heated and controlled thermo-statically to avoid unsafe conditions. It shall be capable ofmaintaining the sample temperature during the entire run at 606 3C (140 6 5F). The thermostatic control shall be capableo
23、f maintaining the temperature within these limits and operatesafely if there is a flammable atmosphere.5.1.4 Electric powered and heated centrifuges must meet allsafety requirements for use in hazardous areas.5.1.5 Calculate the necessary minimum speed of the rotat-ing head in revolutions per minute
24、 (r/min) as follows:r/min 5 1335 =rcf/d (1)where:rcf = relative centrifugal force andd = diameter of swing measured between tips of oppositetubes when in rotating position, mm, orr/min 5 265 =rcf/d (2)where:rcf = relative centrifugal force andd = diameter of swing measured between tips of oppositetu
25、bes when in rotating position, in.5.1.6 Calculate the relative centrifugal force from a mea-sured speed (r/min) as follows:rcf 5 dSr/min1335D2(3)where:d = diameter of swing measured between tips of oppositetubes when in rotating position, mm, orrcf 5 dSr/min265D2(4)where:d = diameter of swing measur
26、ed between tips of oppositetubes when in rotating position, in.5.2 Centrifuge TubesEach centrifuge tube shall be a203-mm (8-in.) cone-shaped tube, conforming to dimensionsgiven in Fig. 1 and made of thoroughly annealed glass. Thegraduations, numbered as shown in Fig. 1, shall be clear anddistinct, a
27、nd the mouth shall be constricted in shape for closurewith a cork. Scale error tolerances and the smallest graduationsbetween various calibration marks are given in Table 1 andapply to calibrations made with air-free water at 20C (68F),when reading the bottom of the shaded meniscus. The accuracy4Ava
28、ilable from Energy Institute, 61 New Cavendish St., London, WIG 7AR,U.K., http:/www.energyinst.org.uk.5Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org. FIG. 1 Eight-Inch (203-mm) Centrifuge TubeD4007082of the graduations o
29、n the centrifuge tube shall be volumetri-cally verified, before use of the tube. The verification shallinclude calibration at each mark up to the 0.25 mL mark (asshown in Fig. 2), and at the 0.5, 1.0, 1.5, 2.0, 50.0, and 100 mLmarks. The tube shall not be used if the scale error at any markexceeds t
30、he applicable tolerance from Table 1.5.3 BathThe bath shall be either a solid metal block bathor a liquid bath of sufficient depth for immersing the centrifugetube in the vertical position to the 100-mL mark. Means shallbe provided for maintaining the temperature at 60 6 3C (1406 5F). For some crude
31、 oils, temperatures of 71 6 3C (160 65F) may be required to melt wax crystals in crude oils. Forthese crude oils, the test temperature shall be maintained highenough to ensure the absence of wax crystals.5.4 50 mL Pipet, Class A, or equivalent volume dispensingdevice, capable of delivering a volume
32、of 50 6 0.05 mL (seeSpecification E 969) for use in the test.6. Solvent6.1 TolueneReagent grade conforming to the specifica-tions of the Committee onAnalytical Reagents of theAmericanChemical Society (ACS)6or to Grade 2 of ISO 5272 orconforming to the EI Specification for Methylbenzenes (Tolu-enes).
33、 (WarningFlammable. Keep away from heat, sparks,and open flame. Vapor harmful. Toluene is toxic. Particularcare must be taken to avoid breathing the vapor and to protectthe eyes. Keep container closed. Use with adequate ventilation.Avoid prolonged or repeated contact with the skin.)6.1.1 Typical cha
34、racteristics for this reagent are:Assay 99.5+ %Color (APHA) 10Boiling range (initial to dry point)(Recorded boiling point 110.6C)2.0CResidue after evaporation 0.001 % max wt/wtSubstances darkened by H2SO4passes testSulfur compounds (as S) 0.003 % max wt/wtWater (H2O) (by Karl Fischer titration) 0.03
35、 % max wt/wt6.1.2 The solvent shall be water-saturated at 60 6 3C (1406 5F) (see 5.3) but shall be free of suspended water. SeeAnnex A1 for the solvent-water saturation procedure.6.2 DemulsifierA demulsifier should be used to promotethe separation of water from the sample and to prevent itsclinging
36、to the walls of the centrifuge tube. The recommendedstock solution is 25 % demulsifier to 75 % toluene. For somecrude oils a different ratio of demulsifier to toluene may berequired. Demulsifiers used in the concentration and quantityrecommended will not add to the water and sediment volumedetermine
37、d. The solution must be stored in a dark bottle that istightly closed.7. Sampling7.1 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.7.2 Only representative samples obtained as
38、specified inPractices D 4057 (API MPMS Chapter 8.1) and PracticeD 4177 (API MPMS Chapter 8.2) shall be used for this testmethod.7.3 Sample Mixingis typically required to obtain a testportion representative of the bulk sample to be tested, butprecautions shall be taken to maintain the integrity of th
39、esample during this operation. Mixing of volatile crude petro-leum containing water or sediments, or both, may result in theloss of light components.Additional information on the mixingand handling of liquid samples can be found in Practice D 5854(API MPMS Chapter 8.3).8. Procedure8.1 Fill each of t
40、wo centrifuge tubes (5.2) to the 50-mLmark with sample directly from the sample container. Using apipet or other suitable volume transfer device (see 5.4), add 506 0.05 mL of toluene, which has been water saturated at 60C(140F) or 71C (160F) (see 5.3). Read the top of themeniscus at both the 50 and
41、100-mL marks. Add 0.2 mL ofdemulsifier solution (6.2) to each tube, using a 0.2-mL pipet orother suitable volume transfer device, such as an automaticpipettor. Stopper the tube tightly and invert the tubes ten timesto ensure that the oil and solvent are uniformly mixed.8.2 In the case where the crud
42、e oil is very viscous andmixing of the solvent with the oil would be difficult, the solventmay be added to the centrifuge tube first to facilitate mixing.Take care to not fill the centrifuge tube past the 100-mL markwith the sample.8.3 Loosen the stoppers slightly and immerse the tubes tothe 100-mL
43、mark for at least 15 min in the bath maintained at60 6 3C (140 6 5F) (see 5.3). Secure the stoppers and againinvert the tubes ten times to ensure uniform mixing of oil andsolvent. (WarningThe vapor pressure at 60C (140F) isapproximately double that at 40C (104F).)8.4 Place the tubes in the trunnion
44、cups on opposite sides ofthe centrifuge to establish a balanced condition. (If the tubescannot be counter-balanced by eye, place them, in theirtrunnion cups, on either side of a balance and equalize theirmasses by the addition of water to the trunnion cups.) Re-tighten the corks and spin for 10 min
45、at a minimum relativecentrifugal force of 600 calculated from the equation given in5.1.6.8.5 Immediately after the centrifuge comes to rest followingthe spin, read and record the combined volume of water and6Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washi
46、ngton, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.TABLE 1 Ce
47、ntrifuge Tube Calibration Tolerancesfor 203-mm (8-in.) TubeRange, mL Subdivision, mL Volume Tolerance, mL0to0.1 0.05 60.02Above 0.1 to 0.3 0.05 60.03Above 0.3 to 0.5 0.05 60.05Above 0.5 to 1.0 0.10 60.05Above 1.0 to 2.0 0.10 60.10Above 2.0 to 3.0 0.20 60.10Above 3.0 to 5.0 0.5 60.20Above 5.0 to 10 1
48、.0 60.50Above 10 to 25 5.0 61.00Above 25 to 100 25.0 61.00D4007083FIG. 2 Procedure for Reading Water and Sediment When Using an ASTM 100-mm Cone-Shaped Centrifuge TubeD4007084sediment at the bottom of each tube, to the nearest 0.05 mLfrom 0.1 to 1-mL graduations, and to the nearest 0.1-mL above1-mL
49、graduations. Below 0.1 mL, estimate to the nearest0.025 mL(refer to Fig. 2). Return the tubes without agitation tothe centrifuge and spin for another 10 min at the same rate.8.6 Repeat this operation until the combined volume ofwater and sediment remains constant for two consecutivereadings. In general, not more than two spinnings are required.8.7 The temperature of the sample during the entire centri-fuging procedure shall be maintained at 60 6 3C (140 6 5F)(see 5.3).8.8 To avoid the danger of tubes breaking in the cups, caremust be taken tha
