1、Designation: D 7261 07An American National StandardStandard Test Method forDetermining Water Separation Characteristics of DieselFuels by Portable Separometer1This standard is issued under the fixed designation D 7261; the number immediately following the designation indicates the year oforiginal ad
2、option 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.This standard has been approved for use by agencies of the Department of Defense.
3、1. Scope*1.1 This test method covers a rapid portable means for fieldand laboratory use to rate the ability of diesel fuels (both neatand those containing additives) to release entrained or emulsi-fied water when passed through fiberglass coalescing material.1.2 This test method is applicable to die
4、sel fuels such asD 975 Grade No. 1 and Grade No. 2 of all sulfur levels, andMIL-F-16884, naval distillate fuel (NATO F-76).NOTE 1This test method is similar to Test Method D 3948 which isapplicable to aviation turbine fuels.1.3 The values stated in SI units are to be regarded as thestandard. The val
5、ues given in parentheses are for informationonly.1.4 This standard does 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 re
6、gulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 975 Specification for Diesel Fuel OilsD 1193 Specification for Reagent WaterD 3948 Test Method for Determining Water SeparationCharacteristics of Aviation Turbine Fuels by PortableSeparometerD 4057 Practice for Manual Sam
7、pling of Petroleum andPetroleum ProductsD 4176 Test Method for Free Water and Particulate Con-tamination in Distillate Fuels (Visual Inspection Proce-dures)D 4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD 4306 Practice for Aviation Fuel Sample Containers forTests Affected b
8、y Trace ContaminationD 4860 Test Method for Free Water and Particulate Con-tamination in Mid-Distillate Fuels (Clear and Bright Nu-merical Rating)D 6426 Test Method for Determining Filterability ofMiddle Distillate Fuel Oils2.2 Military Standard:MIL-F-16884 Fuel, Naval Distillate (NATO F-76)33. Term
9、inology3.1 Definitions:3.1.1 Micro-Separometer rating (DSEP rating), na nu-merical value indicating the ease of separating emulsified waterfrom fuel by coalescence as affected by the presence of surfaceactive materials (surfactants) in the fuel.3.1.2 reference fluid, na reference fluid base to which
10、prescribed quantities of a known surface active agent havebeen added.3.1.2.1 DiscussionThe known surface active agent istypically bis-2-ethylhexyl sodium sulfosuccinate, commonlyreferred to as AOT, dissolved in toluene.3.1.3 surfactants, nin petroleum fuels, surface active ma-terials that could disa
11、rm (de-activate) filter separator (coalesc-ing) elements so that free water is not removed from the fuel inactual service.3.1.3.1 DiscussionTechnically, surfactants affect the in-terfacial tension between water and fuel which affects thetendency of water to coalesce into droplets or not.1This test m
12、ethod is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.14 on Stability and Cleanliness of Liquid Fuels.Current edition approved July 1, 2007. Published August 2007. Originallyapproved in 2006. Last previous editio
13、n approved in 2006 as D 726106a.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 Standardizati
14、on Documents Order Desk, Bldg. 4 Section D, 700Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.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.3.1.4 strong surf
15、actants, nin petroleum fuels, surfaceactive materials that disarm filter separator elements.3.1.4.1 DiscussionStrong surfactants can be refinery pro-cess chemicals left in the fuel or contaminants introducedduring transportation of the fuel.3.1.5 weak surfactants, nin petroleum fuels, surface ac-tiv
16、e materials that do not adversely affect the performance offilter separator elements in actual service.3.1.5.1 DiscussionWeak surfactants are typically certaintypes of additives used in fuels.3.2 Definitions of Terms Specific to This Standard:3.2.1 DSEP rating, nthe Micro-Separometer rating ofdiesel
17、 fuels as measured by this test method.3.2.1.1 DiscussionThe “D” in DSEP stands for dieselfuel. (See 14.1 for more information.)3.2.2 reference fluid base, na distillate diesel fuel that hasbeen carefully cleaned in a prescribed manner to remove allsurface-active contaminants, and having a minimum D
18、SEPrating of 97.3.2.2.1 DiscussionThe reference fluid base should be adiesel fuel typical of fuels to be tested.3.3 Abbreviations:3.3.1 acalternating current3.3.2 AOTAerosol OT (see 8.1)3.3.3 C/Scollect sample3.3.4 dcdirect current3.3.5 MSEPMicro-Separometer3.3.6 DSEPMicro-SeparometerDiesel4. Summar
19、y of Test Method4.1 A 50 mL water/fuel sample emulsion is created in asyringe using a high-speed mixer. The emulsion is thenexpelled from the syringe at a programmed rate through astandard fiber-glass coalescer and the effluent is analyzed foruncoalesced water by a light transmission measurement.4.2
20、 The results are reported on a 0-to-100 scale to thenearest whole number, however the effective range of the testequipment is from 50 to 100. High ratings indicate that wateris easily coalesced, implying that the fuel is relatively free ofsurfactants.4.3 A test can be performed in 5 to 10 min.5. Sig
21、nificance and Use5.1 This test method provides a measure of the presence ofsurfactants in diesel fuels, and can be performed in the field orin a laboratory. Like Test Method D 3948 used for jet fuel, thistest method can detect traces of some refinery treating chemi-cals left in fuel. It can also det
22、ect surface active substancesadded to or picked up by the fuel during handling from pointof production to point of use.5.2 Certain additives, which can act as weak surfactants,give a slightly reduced DSEP rating. Other substances whichare strong surfactants give much lower DSEP ratings.5.3 While fil
23、ter separators have not been common in dieselfuel systems, they could become more prevalent with ULSDcontaining increased additive content to ensure clean, dry fuelsin new engine designs. Weak surfactants, with slightly reducedDSEP ratings, do not affect the ability of filter separators toseparate f
24、ree water from the fuel. Strong surfactants give amuch lower DSEP rating and adversely affect the ability offilter separators to separate free water from the fuel.5.4 Results from this test method do not have a knownrelationship to the rate of water settling in tanks.5.5 The Micro-Separometer has a
25、measurement range from50 to 100. Values obtained outside of those limits are undefinedand invalid.NOTE 2In the event a value greater than 100 is obtained, there is agood probability that light transmittance was reduced by material con-tained in the fuel used to set the 100 reference level. The mater
26、ial wassubsequently removed during the coalescing portion of the test, thus, theprocessed fuel had a higher light transmittance than the fuel sample usedto obtain the 100 reference level resulting in the final rating measuring inexcess of 100.6. Interferences6.1 Any suspended particles, whether soli
27、ds or water drop-lets or haze, in a fuel sample will interfere with this testmethod, which utilizes light transmission of a fuel sample afteremulsification with water and subsequent coalescence.6.2 Non-hydrocarbon components such as oxygenates, es-pecially alcohols, or emulsified water have not been
28、 verifiedfor this test method and will likely interfere.7. Apparatus7.1 A Micro-Separometer4,5instrument is used to performthe test. The unit is portable and self-contained, capable ofoperating on an internal rechargeable battery pack or beingconnected to an ac power source using power cords which a
29、reavailable for various voltages. Connection to an ac powersource will provide power to the unit and affect batteryrecharge. The accessories can be packed in the cover of thelockable case.7.1.1 The Emcee Model 1140 Micro-Separometer Mark VDeluxe and associated control panel is shown in Fig. 1. Theem
30、ulsifier is on the right side of the raised panel and thesyringe drive mechanism is on the left side. The control panelcontaining the operating controls (pushbuttons) is mounted onthe fixed panel in the left side of the case. Table 1 lists themanual and audio operating characteristics of the instrum
31、ent.Acircuit breaker located on the control panel provides protectionfor the ac power circuit. The turbidimeter is located under themain control panel and consists of a well in which the samplevial is placed, a light source, and a photocell.NOTE 3Of the lettered (A-G) pushbuttons, only the D pushbut
32、ton isapplicable to this test method.4The sole source of supply of the apparatus known to the committee at this timeis the Model 1140 Micro-Separometer Mark V Deluxe, available from EMCEEElectronics, Inc., 520 Cypress Ave., Venice, FL 34285, U.S.A. www.emcee-. If you are aware of alternative supplie
33、rs, please provide thisinformation to ASTM International Headquarters. Your comments will receivecareful consideration at a meeting of the responsible technical committee,1whichyou may attend.5The Model 1140 Micro-Separometers Mark III and Mark V Standard versionsmay also be used, but they are no lo
34、nger supported by the manufacturer. Foroperating procedures using these instruments, the user is referred to Test MethodD 394887.D72610727.2 Beaker, Catch Pan, or Plastic Container(Suppliedwith each Micro-Separometer) used to receive the waste fuelduring the coalescence period of the test.7.3 PipetA
35、n automatic 50-L hand pipet (supplied witheach Micro-Separometer) designed to accept a disposableplastic tip.8. Reagents and Materials8.1 Aerosol OT, (AOT), solid (100 % dry) bis-2-ethylhexylsodium sulfosuccinate.8.2 Dispersing AgentToluene solution (WarningFlammable. Vapor harmful.) containing 1 mg
36、 of Aerosol OTper milliliter of toluene.8.3 Expendable Materials needed to perform the test areshown in Fig. 2 and consist of the following:68.3.1 Syringe Plug, (A)A plastic plug used to stopper thesyringe during the clean and emulsion cycles.8.3.2 Syringe, (Barrel (B) and Plunger (C)A disposable50
37、mL plastic syringe.8.3.3 Vials, (D), 25-mm outside diameter vial premarked forproper alignment in the turbidimeter well.8.3.4 DCell7Coalescer, (E) an expendable, pre-calibratedaluminum coalescer cell with a tapered end to fit the syringe. Itis labeled in a white background with black lettering:DCELL
38、t, DIESEL FUEL, D 72618.3.4.1 In order for a coalescer to be acceptable for this testmethod, it shall have been manufactured using 2-grades offiberglass and have passed factory calibration tests for air flowand leakage.8.3.5 Disposable Plastic Pipet Tip (F)Used with an auto-matic 50-L hand pipet (Fi
39、g. 2, G).8.3.6 Container (H)A clean container of double-distilledwater (8.7).8.4 Reference Fluid BaseA surfactant-free, clean, distil-late diesel fuel which is used to verify proper operation and isprepared in the manner described in Annex A1 (see 3.2.2).(WarningFlammable. Vapor harmful.)8.5 Referen
40、ce Fluid(WarningFlammable. Vapor harm-ful.) A fluid used for checking the operational performance of6A new syringe, pipet tip, test sample vial, syringe plug, DCell coalescer(trademarked) and double distilled water are used in each test. These expendablematerials are available from Emcee Electronics
41、, Inc. in a kit, termed the DCellMicro-Separometer Six Pack (trademarked), containing supplies for six tests (Fig.3).7The term “DCell” and logo are registered trademarks of EMCEE Electronics,Inc, 520 Cypress Ave., Venice, FL 34285.FIG. 1 Micro-Separometer Mark V Deluxe and Associated Control PanelTA
42、BLE 1 Manual and Audio Operating Characteristics of theEmcee Model 1140 Micro-Separometer Instrument forMode D OperationAvailable Test Mode(s) Function Mark V DeluxeTest Mode - Select Mode DDepress D PushbuttonSyringe Drive Not requiredSpeed Selection Not requiredClean CycleDepress START PushbuttonI
43、nitiate Automatic Test SequenceDepress START PushbuttonCancel Automatic SequenceDepress RESET Pushbutton1st Meter Read1st Meter Adjust Depress ARROWED Pushbuttons2nd Meter Read2nd Meter Adjust Depress ARROWED PushbuttonsCollect Sample Short Tone and C/SAnnunciator Lamp Illuminates3rd Meter ReadRecor
44、d Measurement Pulsed Tone Sounds5sinto3rdMeterReadFIG. 2 Test Supplies and Small PartsFIG. 3 Six Pack and Test AccessoriesD7261073the Micro-Separometer instrument), consisting of increasingconcentrations (0 to 1.6 mL/L) of dispersing agent added to thereference fluid base. The DSEP ratings for this
45、range ofconcentrations appear in Table 2. The reference fluids areprepared and tested as described in Sections 12 and 13.8.6 Toluene, ACS reagent grade. (WarningFlammable.Vapor harmful.)8.7 Water, clean, double-distilled and surfactant-free:D 1193 Type IV reagent water, re-distilled. In practice, re
46、-distillation of commercial distilled water has proven to besatisfactory.8.7.1 Use of water other than double-distilled water (such astap water) will render test results invalid.9. Hazards9.1 The primary hazard in this test method is the flamma-bility of the fuels that are tested. Take suitable prec
47、autions toavoid sparks, flames or sources of ignition.9.2 Minimize worker exposure to breathing fuel vapors.10. Preparation of Apparatus10.1 Locate the instrument on a clean workbench in an areawhere the temperature is between 18 and 29C (65 and 85F)and does not vary more than 63C (5F).10.2 Open the
48、 case, and raise the right panel until com-pletely vertical and locked in place.10.2.1 If ac power is available, connect the power cord.10.2.2 If the internal battery power is used, ensure that thebatteries are charged sufficiently to perform the desired numberof tests.NOTE 4Low battery power is ind
49、icated when the power lamp does notilluminate. To recharge the battery, connect the instrument to an ac powersource for at least 16 h (full charge) prior to use. Approximately 25 testscan then be performed.10.2.3 Turn the Mark V Deluxe instrument on by depressingthe switch (pushbutton) marked ON.NOTE 5The on-power indicator light will alternately pulse on and offwhen the instrument is connected to an ac power source and will stay oncontinuously when operated by the battery pack. Flickering of the powerindicator light, during
