1、Designation: D4007 11 (Reapproved 2016)Manual of Petroleum Measurement Standards (MPMS), Chapter 10.3Standard Test Method forWater and Sediment in Crude Oil by the Centrifuge Method(Laboratory Procedure)1This standard is issued under the fixed designation D4007; the number immediately following the
2、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 describes
3、 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 watercontent. When a highly ac
4、curate value is required, the revisedprocedures for water by distillation, Test Method D4006 (APIMPMS Chapter 10.2) (Note 1), and sediment by extraction,Test Method D473 (API MPMS Chapter 10.1), shall be used.NOTE 1Test Method D4006 (API MPMS Chapter 10.2) has beendetermined to be the preferred and
5、most accurate method for thedetermination of water.1.2 The values stated in SI units are to be regarded asstandard.1.2.1 ExceptionThe values given in parentheses are forinformation only.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is th
6、eresponsibility 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 Test Method for Water i
7、n 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-Preventing Characteristics ofInhibited Mineral Oil in the Presence of WaterD1796 Test
8、Method for Water and Sediment in Fuel Oils bythe Centrifuge Method (Laboratory Procedure) (APIMPMS Chapter 10.6)D4006 Test Method for Water in Crude Oil by Distillation(API MPMS Chapter 10.2)D4057 Practice for Manual Sampling of Petroleum andPetroleum Products (API MPMS Chapter 8.1)D4177 Practice fo
9、r 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)D5854 Practice for Mixing and Handling of Liquid Samplesof Petroleum and Petroleum Products (API MPMS Chap-ter 8.3)E969
10、Specification for Glass Volumetric (Transfer) Pipets2.2 API Standards:3MPMS Chapter 8.1 Manual Sampling of Petroleum andPetroleum Products (ASTM Practice D4057)MPMS Chapter 8.2 Automatic Sampling of Petroleum andPetroleum Products (ASTM Practice D4177)MPMS Chapter 8.3 Mixing and Handling of Liquid S
11、amplesof Petroleum and Petroleum Products (ASTM PracticeD5854)MPMS Chapter 10.1 Determination of Sediment in CrudeOils and Fuel Oils by the Extraction Method (ASTM TestMethod D473)MPMS Chapter 10.2 Determination of Water in Crude Oil byDistillation (ASTM Test Method D4006)MPMS Chapter 10.4 Determina
12、tion of Sediment and Waterin Crude Oil by the Centrifuge Method (Field Procedure)MPMS Chapter 10.5 Determination of Water in Petroleum1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and the API Committee onPetroleum Measurement and
13、 is the direct responsibility of Subcommittee D02.02/COMQ the joint ASTM-API Committee on Hydrocarbon Measurement forCustody Transfer (Joint ASTM-API). This test method has been approved by thesponsoring committees and accepted by the Cooperating Societies in accordancewith established procedures.Cu
14、rrent edition approved June 1, 2016. Published July 2016. Originally approvedin 1981. Last previous edition approved in 2011 as D4007 111. DOI: 10.1520/D4007-16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book o
15、f ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American Petroleum Institute (API), 1220 L. St., NW,Washington, DC 20005-4070, www.api.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428
16、-2959. United States1Products 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 D1796)MPMS Chapter 10.9 Test Method for Water in Crude Oils byCoulometric
17、Karl Fischer Titration (ASTM Test MethodD4928)2.3 IP Standard:4Methods Book, Appendix B Specification for Methylben-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 in
18、to a cone-shaped centrifuge tube. Aftercentrifugation, the volume of the higher density water andsediment layer 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 processi
19、ng.Adetermination of water and sediment content isrequired to measure accurately net volumes of actual oil insales, 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
20、rooms or sample rooms due to safety concerns forproper ventilation and handling.4.2 This test method may not be suitable for crude oils thatcontain alcohols that are soluble in water. In cases where theimpact on the results may be significant, the user is advised toconsider using another test method
21、, such as Test MethodD4928 (API MPMS Chapter 10.9).5. Apparatus5.1 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 s
22、hall be used (see 5.1.6).5.1.2 The revolving head, trunnion 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
23、 centrifuge is in motion. Thecentrifuge shall be enclosed 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 durin
24、g the entire run at60 C 6 3 C (140 F 6 5 F). The thermostatic control shallbe capable of maintaining the temperature within these limitsand operate safely 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.
25、5 Calculate the necessary minimum speed of the rotat-ing head 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 =
26、relative centrifugal force andd = diameter of swing measured between 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 w
27、hen in rotating position, mm, orrcf 5 dSr/min265D2(4)where:d = 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 ann
28、ealed glass. Thegraduations, numbered as shown in Fig. 1, shall 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-f
29、ree water at 20 C (68 F),when reading the bottom of the shaded meniscus. 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 (asshown in Fig. 2), and at the 0.5
30、mL, 1.0 mL, 1.5 mL, 2.0 mL,50.0 mL, and 100 mL marks. The tube shall not be used if thescale error at any mark exceeds the applicable tolerance fromTable 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 p
31、osition to the 100 mL mark. Means shallbe provided for maintaining the temperature at 60 C 6 3C(140 F 6 5 F). For some crude oils, temperatures of 71 C 63 C (160 F 6 5 F) may be required to melt wax crystals incrude oils. For these crude oils, the test temperature shall bemaintained high enough to e
32、nsure the absence of wax crystals.4Available 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.D4007 11 (2016)25.4 50 mL Pipet,
33、Class A, or equivalent volume dispensingdevice, capable of delivering a volume of 50 mL 6 0.05 mL(see Specification E969) 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
34、 of ISO 5272 orconforming to the EI Specification for Methylbenzenes (Tolu-enes). (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
35、 ventilation.Avoid prolonged or repeated contact with the skin.)6.1.1 Typical characteristics for this reagent are:Assay 99.5+ %Color (APHA) 10Boiling range (initial to dry point)(Recorded boiling point 110.6C)2.0 CResidue after evaporation 0.001 % max wt/wtSubstances darkened by H2SO4passes testSul
36、fur compounds (as S) 0.003 % max wt/wtWater (H2O) (by Karl Fischer titration) 0.03 % max wt/wt6.1.2 The solvent shall be water-saturated at 60 C 6 3C(140 F 6 5 F) (see 5.3) but shall be free of suspended water.See Annex A1 for the solvent-water saturation procedure.6.2 DemulsifierA demulsifier shoul
37、d 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 may berequired. Demulsifiers used in the conce
38、ntration 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 any pipe, tank, or other system and toplace the
39、 sample into the laboratory test container.7.2 Only representative samples obtained as specified inPractices D4057 (API MPMS Chapter 8.1) and Practice D4177(API MPMS Chapter 8.2) shall be used for this test method.7.3 Sample Mixingis typically required to obtain a testportion representative of the b
40、ulk 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 information on the mixingand handling of liquid sample
41、s can be found in Practice D5854(API MPMS Chapter 8.3).8. Procedure8.1 Fill each of two centrifuge tubes (5.2) to the 50 mLmarkwith sample directly from the sample container. Using a pipetor other suitable volume transfer device (see 5.4), add 50 mL 60.05 mL of toluene, which has been water saturate
42、d at 60 C(140 F) or 71 C (160 F) (see 5.3). Read the top of themeniscus at both the 50 mL 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. Stopper the tube tightly and invert the tubes t
43、en 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 not fill the centrifuge tube past the 10
44、0 mL markwith the sample.6Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the
45、 United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.FIG. 1 Eight-Inch (203 mm) Centrifuge TubeTABLE 1 Centrifuge Tube Calibration Tolerancesfor 203 mm (8 in.) TubeRange, mL Subdivision, mL Volume Tolerance, mL0 to 0.1 0.05 0.02Above 0.1 to 0.3
46、0.05 0.03Above 0.3 to 0.5 0.05 0.05Above 0.5 to 1.0 0.10 0.05Above 1.0 to 2.0 0.10 0.10Above 2.0 to 3.0 0.20 0.10Above 3.0 to 5.0 0.5 0.20Above 5.0 to 10 1.0 0.50Above 10 to 25 5.0 1.00Above 25 to 100 25.0 1.00D4007 11 (2016)3FIG. 2 Procedure for Reading Water and Sediment When Using an ASTM 100-mm
47、Cone-Shaped Centrifuge TubeD4007 11 (2016)48.3 Loosen the stoppers slightly and immerse the tubes tothe 100 mL mark for at least 15 min in the bath maintained at60 C 6 3 C (140 F 6 5 F) (see 5.3). Secure the stoppersand again invert the tubes ten times to ensure uniform mixingof oil and solvent. (Wa
48、rningThe vapor pressure at 60 C(140 F) is approximately double that at 40 C (104 F).)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 either side of a b
49、alance 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 and record the combined volume of water andsediment at the bottom of each tube, to the nearest 0.05 mLfrom 0.1 mL to 1 mL graduations, and to the nearest 0.1 mLabove 1 mLgraduations. Below 0.1 mL, estimate to the nearest0.025 mL(refer to F
