1、Designation: D2709 16Standard Test Method forWater and Sediment in Middle Distillate Fuels by Centrifuge1This standard is issued under the fixed designation D2709; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last re
2、vision. 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.1. Scope*1.1 This test method covers the determinat
3、ion of the volumeof free water and sediment (as a percentage of the sample) thatis suspended in the bulk fuel in middle distillate fuels withviscosities in the range of 1.0 mm2/s to 4.1 mm2/s at 40 C(1.0 cSt to 4.1 cSt at 104 F) and densities in the range of770 kg m3to 900 kg m3at 15 C.NOTE 1Fuels c
4、orresponding to Specification D396 Grades No. 1 and2, D975 Grades No. 1-D and 2-D, Specification D2880 Grades No. 0-GT,1-GT and 2-GT, and Specification D3699 Grades No. 1-K and 2-K andsimilar middle distillate fuels and blendstocks will usually fall in thisviscosity and density range. Test Method D1
5、796 is intended for higherviscosity fuel oils.1.2 The values stated in SI units are to be regarded asstandard.1.2.1 ExceptionThe non-SI values are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of
6、the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D396 Specification for Fuel OilsD975 Specification for Diesel Fuel OilsD1796 Test Method for Water and Se
7、diment in Fuel Oils bythe Centrifuge Method (Laboratory Procedure)D2880 Specification for Gas Turbine Fuel OilsD3699 Specification for KerosineD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4175 Terminology Relating to Petroleum Products, LiquidFuels, and LubricantsD4177 Pract
8、ice for Automatic Sampling of Petroleum andPetroleum Products3. Terminology3.1 For definitions of terms used in this test method, refer toTerminology D4175.3.2 Definitions:3.2.1 free water, nwater in excess of that soluble in thefuel at the temperature of the test and appearing in the fuel asa haze,
9、 cloudiness, droplets, or water layer.3.2.1.1 DiscussionNote that when there is a water layer ina biodiesel fuel blend, there can be water-soluble componentspresent in the free water.3.3 Abbreviations:3.3.1 rcfrelative centrifugal force.4. Summary of Test Method4.1 A 100 mL sample of the undiluted f
10、uel is centrifuged ata relative centrifugal force (see 6.2) of 800 for 10 min at 21 Cto 32 C (70 F to 90 F) in a specified centrifuge tube. Aftercentrifugation, the volume of free water and sediment that hassettled into the tip of the centrifuge tube is read to the nearest0.005 mL and reported as th
11、e volumetric percent water andsediment by centrifuge.5. Significance and Use5.1 This test method is used as an indication of free waterand sediment suspended as haze, cloudiness, or droplets inmiddle distillate fuels such as Grades No. 1 and 2 fuel oil(Specification D396), Grades No. 1-D and 2-D die
12、sel fuel(Specification D975), and Grades No. 0-GT, 1-GT, and 2-GTgas turbine fuels (Specification D2880), similar fuels andblendstocks used to make these fuels.5.2 Appreciable amounts of free water and sediment in afuel oil tend to cause fouling of fuel-handling facilities and togive trouble in the
13、fuel system of a burner or engine. Anaccumulation of sediment in storage tanks and on filter screenscan obstruct the flow of oil from the tank to the combustor.Free water in middle distillate fuels can cause corrosion of1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Pr
14、oducts, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.14 on Stability and Cleanliness of Liquid Fuels.Current edition approved April 1, 2016. Published May 2016. Originallyapproved in 1968. Last previous edition approved in 2011 as D2709 96 (2011)1.DOI: 10.1520/D27
15、09-16.2For 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 section appears at the end of thi
16、s standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1tanks and equipment, and if detergent is present, the water cancause emulsions or a hazy appearance. Free water can supportmicrobiological growth at fuel-water interfaces in fu
17、el systems.6. Apparatus6.1 Centrifuge, capable of spinning one or more pairs offilled centrifuge tubes at a speed which can be controlled togive a relative centrifugal force (rcf) of 800 6 60 at the tip ofthe tubes. The revolving head, trunnion rings, and trunnioncups, including the cushions, shall
18、be soundly constructed towithstand the maximum centrifugal force capable of beingdelivered by the power source. The trunnion cups and cushionsshall support the tubes when the centrifuge is in motion. Thecentrifuge shall be enclosed by a metal shield or case strongenough to eliminate danger if any br
19、eakage occurs.6.2 The data in Table 1 may be used to determine thecentrifuge speed setting required for the centrifuge to meetrelative centrifugal force requirements for this method and wasdeveloped using the following equations:r/min 5 265 =rcf/d (1)where:rcf = relative centrifugal force, andd = di
20、ameter of swing, in inches, measured between tips ofopposite tubes when in rotating position orr/min 5 422=rcf/d (2)where:rcf = relative centrifugal force, andd = diameter of swing, in centimetres, measured betweentips of opposite tubes when in rotating position.6.3 Centrifuge Tube, equipped with a
21、stopper, either:6.3.1 Cone-shaped, 100 mL with capillary tip capable ofmeasuring 0.01 mL and readable by estimation to 0.005 mL, or6.3.2 Pear-shaped, 100 mL, with tube tip having gradua-tions of 0.01 mL over the range of 0 mL to 0.2 mL.7. Sampling7.1 Sampling shall be consistent with the procedures
22、ofPractices D4057 or D4177.7.2 The sample for a laboratory test will normally be analiquot of a much larger sample taken for full or partialspecification testing. Allow the sample container and itscontents to equilibrate between 21 C to 32 C (70 F to90 F). The laboratory test temperature should not
23、be lowerthan the temperature at which the fuel is stored or used as toolow a temperature can cause water haze to form from addi-tional free water separation, making the test more severe.8. Procedure8.1 Temperature ControlAfter the sample container andits contents have equilibrated to laboratory temp
24、erature, be-tween 21 C to 32 C (70 F to 90 F), agitate the full sampleby hand or preferably by a mechanical shaker for 10 min toensure homogeneity.8.2 As soon as possible, to prevent losing any water orsediment by settling, fill the centrifuge tube to the 100 mLmark directly from the sample containe
25、r. Stopper and place ina trunnion cup in the centrifuge.8.3 Prepare a second centrifuge tube to the same mass as thecentrifuge tube in 8.2, and place in the trunnion cup oppositethe first tube to establish a balanced condition. It is practical tofill the second tube with another portion of the sampl
26、e beingevaluated. This practice gives a second tube of consistent massto the first tube, and allows the sample to be analyzed induplicate.8.4 Close the centrifuge cover, turn on and centrifuge for10 min at a speed sufficient to produce a relative centrifugalforce (rcf) of 800 6 60 at the tip of the
27、whirling tubes. (For therelationship between diameter of swing, rcf, and r/min, seeTable 1.)8.5 When the centrifuge has stopped moving after the10 min spin, remove the centrifuge tube, estimate and recordthe combined water and sediment volume at the bottom of thetube to the nearest 0.005 mL.8.6 Sinc
28、e a 100 mL sample is used, the volume of water andsediment in millilitres is numerically the same as the percent byvolume.9. Report9.1 Report the volume of the combined water and sedimentread from the tube as the percentage of the total sample to thenearest 0.01 % and reference this test method.9.1.
29、1 Report results lower than 0.01 mL as 0.01 % byvolume.10. Precision and Bias310.1 PrecisionThe precision of the procedure in this testmethod, for measuring the percent by volume amount ofcombined free water and sediment in middle distillate fuels bycentrifuge was determined by an interlaboratory st
30、udy (ILS)performed by six individuals using 13 samples at a commonsite.3Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D02-1308.TABLE 1 Rotation Speeds Applicable for Centrifugesof Various Diameters of SwingDiameter of SwingAr/m
31、inBat 800rcfin. cm12 30.5 216013 33.0 208014 35.6 200015 38.1 193016 40.6 187017 43.2 182018 45.7 177019 48.3 172020 50.8 168021 53.3 164022 55.9 160023 58.4 156024 61.0 1530AMeasured between tips of opposite tubes when in rotating position.B“r min” is the correct SI symbol for the former term “rpm.
32、”D2709 162NOTE 2Precision data for this test used pear-shaped tubes.10.1.1 RepeatabilityThe difference between successivemeasured volume percent amounts of combined water andsediment obtained by the same operator using the samecentrifuge and type of pear-shaped tube under constant oper-ating conditi
33、ons on identical middle distillate fuel samples atthe same site would, in the long run and in the normal andcorrect operation of the test method, exceed 0.014 % byvolume in 1 case in 20.10.1.2 ReproducibilityThe difference between two singleindependent measurements of volume percent amounts ofcombin
34、ed water and sediment obtained by different operator/centrifuge pairs using the same type of pear-shaped tube onidentical middle distillate fuel samples at the same site would,in the long run, in the normal and correct operation of the testmethod, exceed 0.041 % by volume in 1 case in 20.10.2 BiasSi
35、nce there is no accepted reference materialsuitable for determining the bias for this procedure for mea-suring water, the bias is not available for this test method.11. Keywords11.1 centrifuge; centrifuge tube; middle distillate fuel; waterand sedimentSUMMARY OF CHANGESSubcommittee D02.14 has identi
36、fied the location of selected changes to this standard since the last issue(D2709 96 (2011)1) that may impact the use of this standard. (Approved April 1, 2016.)(1) Numerous editorial changes were made throughout thestandard to align it with current Form and Style requirementsand correct SI units.(2
37、) Scope1.1, 1.2, and Note 1were revised to include Speci-fication D396, related products and blendstocks, and update theformatting of units.(3) Subsection 2.1Terminology D4175 and Practice D4177were added.(4) Distillate fuel definition was deleted from Section 3;subsection 3.2.1, a definition for fr
38、ee water, was added.(5) Subsection 3.1 was added to reference Terminology D4175.(6) Subsection 3.3, Abbreviations, specifically 3.3.1 “rcf” wasadded.(7) Subsection 4.1 was modified to simplify the description ofthe centrifuge tube.(8) Subsections 5.1 and 5.2 were clarified.(9) Table 1, the column fo
39、r “Rpm at 500 rcf” was deleted as notbeing required; added new footnote B for “r/min.”(10) Wording in subsections 6.1, 6.2, and 6.3 was clarified.(11) Subsection 7.1, added reference to Practice D4177.(12) Subsection 7.2, clarified wording.(13) Subsection 8.1, “Warningflammable” was deleted.(14) Sub
40、section 8.2 was modified and rephrased to generatenew subsections 8.3, 8.4, 8.5, and 8.6.(15) Report subsection 9.1 was revised, and new subsection9.1.1 was added to correct the reporting of low results.(16) Precision subsection 10.1 was revised.ASTM International takes no position respecting the va
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