1、Designation: D 4007 02 (Reapproved 2006)Designation: 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
2、 4007; 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 (e) indicates an editorial change since the last revision or reap
3、proval.1. Scope1.1 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 t
4、han the actual watercontent. 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 1
5、0.2) has beendetermined 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
6、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 specificprecautionary statements, see 6.1.2. Referenced Documents2.1 ASTM Standards:2D
7、95 Test 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
8、Presence 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
9、 Chapter 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:3
10、MPMS 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 C
11、hapter 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 (F
12、ield 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
13、 under 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 D02.02.0B /COMQ, the jointASTM-API Committee on Sampling, Sediment, Water.Current edition approved Nov. 1, 2006. Publish
14、ed December 2006. Originallyapproved in 1981. Last previous edition approved in 2002 as D 4007 02.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
15、in 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), 1
16、220 L. St., NW, Wash-ington, DC 20005-4070, http:/api-ec.api.org.1Copyright 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 Methylben-zenes (Toluenes)2.4 ISO Standard:5ISO 5272:1979 To
17、luene 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 sedimentlayer at the bottom of the tube is read.4. Significance an
18、d 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 insales, taxation, exchanges, and custody transfers.5. Ap
19、paratus5.1 Centrifuge:5.1.1 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, trunn
20、ion rings, and trunnion cups,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 enclose
21、d by a metal shield or case 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
22、control shall be capableof 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
23、in revolutions per minute (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 b
24、etween tips of oppositetubes 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 =
25、 diameter of swing measured 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, shal
26、l be clear anddistinct, and 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 m
27、eniscus. The accuracyof the graduations on 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 (as4Available from the Institute of Petroleum, 61 New Cavendish Street, London,W1G 7AR, U.K.5Availab
28、le 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 TubeD 4007 02 (2006)2shown 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
29、any markexceeds the 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
30、). For some crude 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 del
31、ivering a volume of 50 6 0.05 mL (seeSpecification E 969) for use in the test.6. Solvent6.1 Tolueneconforming to the IP Specification for Meth-ylbenzenes (Toluenes) or to ISO 5272. (WarningFlammable. Keep away from heat, sparks, and open flame.Vapor harmful. Toluene is toxic. Particular care must be
32、 takento avoid breathing the vapor and to protect the eyes. Keepcontainer closed. Use with adequate ventilation. Avoid pro-longed or repeated contact with the skin.)6.1.1 Typical characteristics for this reagent are:Molecular weight C6H5CH392.14Color (APHA) 10Boiling range (initial to dry point)A2.0
33、C (3.6F)Residue after evaporation 0.001 %Substances darkened by H2SO4passes ACS testSulfur compounds (as S) 0.003 %_ARecorded boiling point 110.6C6.1.2 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 saturati
34、on procedure.6.2 DemulsifierA demulsifier should be used to promotethe separation of water from the sample and to prevent itsclinging 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
35、 may berequired. Demulsifiers used in the concentration and quantityrecommended will not add to the water and sediment volumedetermined. 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
36、any pipe, tank, or other system and toplace the sample into the laboratory test container.7.2 Only representative samples obtained as 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
37、 to obtain a testportion representative of the bulk sample to be tested, butprecautions shall be taken to maintain the integrity of thesample during this operation. Mixing of volatile crude petro-leum containing water or sediments, or both, may result in theloss of light components.Additional inform
38、ation 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 two 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.
39、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 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. Stoppe
40、r 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 crude 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
41、 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 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 oi
42、l andsolvent. (WarningThe vapor pressure at 60C (140F) isapproximately double that at 40C (104F).)8.4 Place the tubes in the trunnion 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 eithe
43、r 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 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 an
44、d record the combined volume of water andsediment 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 graduations. Below 0.1 mL, estimate to the nearest0.025 mL(refer to Fig. 2). Return the tubes without agitation tothe centrifuge and s
45、pin 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.TABLE 1 Centrifuge Tube Calibration Tolerancesfor 203-mm (8-in.) TubeRange, mL Subdivisi
46、on, 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 1.0 60.50Above 10 to 25 5.0 61.00Above 25 to 100 25.0 61.00D 4007 02 (2006)3FIG
47、. 2 Procedure for Reading Water and Sediment When Using an ASTM 100-mm Cone-Shaped Centrifuge TubeD 4007 02 (2006)48.7 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, car
48、emust be taken that the tubes are bedded onto the bottomcushion so that no part of the tube is in contact with the rim ofthe cup.9. Calculation9.1 Record the final volume of water and sediment in eachtube. If the difference between the two readings is greater thanone subdivision on the centrifuge tu
49、be (see Table 1)or0.025 mL for readings of 0.10 mL and below, the readings areinadmissible and the determination shall be repeated.9.2 Express the sum of the two admissible readings as thepercentage by volume of water and sediment; report the resultsas shown in Table 2.10. Precision and Bias10.1 PrecisionThe precision of this test method, as deter-mined by statistical examination of interlaboratory test resultsin the range from 0.01 to 1.0 %, is described in 10.1.1 and10.1.2.10.1.1 RepeatabilityThe difference between two test re-sults,
