1、Designation: D2068 12aStandard Test Method forDetermining Filter Blocking Tendency1This standard is issued under the fixed designation D2068; 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 pa
2、rentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.INTRODUCTIONThis test method describes three procedures using different filter media. The result of any test isdependent on the filter mandated in the procedur
3、e. If a specification requires a specific D2068procedure, do not substitute a different procedure or filter without agreement from the specifier.1. Scope*1.1 This test method covers three procedures for the deter-mination of the filter blocking tendency (FBT) and filterabilityof middle distillate fu
4、el oils and liquid fuels such as biodieseland biodiesel blends. The 3 procedures and associated filtertypes, are applicable to fuels within the viscosity range of 1.3to 6.0 mm2/s at 40C.NOTE 1ASTM specification fuels falling within the scope of this testmethod are: Specifications D396 Grades No 1 an
5、d 2; Specification D975Grades 1-D, low sulfur 1-D and 2-D; Specification D2880 Grades 1-GTand 2-GT; Specification D6751.1.2 This test method is not applicable to fuels that containfree (undissolved) water (see 7.3).1.3 The values stated in SI units are to be regarded asstandard. No other units of me
6、asurement are included in thisstandard.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 regulatory l
7、imitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D396 Specification for Fuel OilsD975 Specification for Diesel Fuel OilsD2880 Specification for Gas Turbine Fuel OilsD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4176 Test Method for Free Water and Particulate
8、 Contami-nation in Distillate Fuels (Visual Inspection Procedures)D4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD4860 Test Method for Free Water and Particulate Contami-nation in Middle Distillate Fuels (Clear and Bright Nu-merical Rating)D6300 Practice for Determination of
9、 Precision and BiasData for Use in Test Methods for Petroleum Products andLubricantsD6426 Test Method for Determining Filterability of MiddleDistillate Fuel OilsD6708 Practice for Statistical Assessment and Improvementof Expected Agreement Between Two Test Methods thatPurport to Measure the Same Pro
10、perty of a MaterialD6751 Specification for Biodiesel Fuel Blend Stock (B100)for Middle Distillate Fuels2.2 ISO Standard:3ISO 5636-5 Paper and BoardDetermination of Air Per-meance and Air Resistance (Medium Range) Part 5Gurley Method2.3 ASTM Adjuncts:D2PP, Determination of Precision and Bias Data for
11、 Use inTest Methods for Petroleum Products4CompTM, Standard Practice for Statistical Assessment andImprovement of the Expected Agreement between TwoTest Methods that Purport to Measure the Same Propertyof a Material43. Terminology3.1 Definitions of Terms Specific to This Standard:1This test method i
12、s 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 Dec. 1, 2012. Published March 2013. Originallyapproved in 1997. Last previous edition approv
13、ed in 2012 as D206812. DOI:10.1520/D2068-12A.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
14、American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.4This adjunct has been withdrawn and is no longer available.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700
15、, West Conshohocken, PA 19428-2959. United States13.1.1 filter blocking tendency (FBT), nof certain fuels,acalculated dimensionless value that defines the tendency ofparticulates in a fuel to plug or block a filter.3.1.1.1 DiscussionThe value is calculated using the pres-sure across the filter or th
16、e volume of fuel filtered at the end ofthe test. Depending on the outcome of the test, one of twoequations is applied. See Section 10, Calculation. See 5.6 forinterpretation of results.3.1.2 filterability, nof certain fuels, the relationship be-tween the volume of sample filtered and the measured pr
17、essureincrease across the filter.3.1.2.1 DiscussionThe filterability of the fuel can beassessed by recording the pressure when a specific volume offuel has flowed through the filter, or recording the volumewhen a specific pressure across the filter has been achieved.This assessment may be assisted b
18、y plotting a volume versuspressure graph. See Appendix X1.4. Summary of Test Method4.1 A test portion of the fuel to be analysed is passed at aconstant rate of flow (20 mL/min) through a specified filtermedium. The pressure difference across the filter, and thevolume of fuel passing the filter, are
19、monitored until thepressure reaches 105 kPa or the volume of fuel passing thefilter medium reaches 300 mL. The pressure and flow are thenused to calculate the filter blocking tendency, where a lownumber indicates a good fuel (see 5.6).4.2 The glass fiber filters specified for Procedures A and Bare b
20、oth 1.6 m nominal pore diameter; Filter B is a pre-assembled encapsulated type.4.3 The pre-assembled nylon filter specified for Procedure Chasa5mnominal pore diameter.5. Significance and Use5.1 This test method is intended for use in evaluating thecleanliness of middle distillate fuels, and biodiese
21、l and bio-diesel blends for specifications and quality control purposes.5.2 The filter media specified in the three procedures are allsuitable for the materials in the Scope. Specifications calling upthis test method should state the procedure required.5.3 A change in filtration performance after st
22、orage orpretreatment can be indicative of changes of fuel condition.5.4 The filterability of fuels varies depending on filterporosity and structure and therefore results from this testmethod might not correlate with full scale filtration.5.5 Causes of poor filterability in industrial/refinery filter
23、sinclude fuel degradation products, contaminants (includingwater) picked up during storage or transfer, effects due totemperature or composition for bio fuels, incompatibility ofcommingled fuels, or interaction of the fuel with the filtermedia.Any of these could correlate with orifice or filter syst
24、emplugging, or both.5.6 The results of the FBT test can range from 1 with a fuelwith very good filterability, to over 100 for a fuel with poorfilterability. The selection of a single FBT number to define apass or fail criteria is not possible as this will be dependent onthe fuel type and application
25、s.6. Apparatus6.1 GeneralThe apparatus, as described in Annex A1 andshown in Fig. A1.1, is available as a manufactured unit or canbe constructed from individual components.6.2 Filter Media and Assemblies:NOTE 2Effective filtration areas were determined by measuring thediameter of the sediment in the
26、 centre of the filter media.6.2.1 Filter A, for Procedure A.6.2.1.1 Filter Housing,5stainless steel, nominal 13 mmdiameter with a Luer fitting at the top where it connects withthe filtration apparatus. Fig. 1 shows the assembly.6.2.1.2 Filter Media,6glass fiber, 1.6 m nominal porediameter, nominal 1
27、3 mm diameter and with an effectivefiltration area of 63.6 to 78.6 mm2. Filter media shall be batchselected to have a Gurley time (ISO 5636-5) of between 12.5and 13.4 s for 300 mL.6.2.2 Filter B,7for Procedure B.6.2.2.1 Filter Housing, disposable polypropylene “syringetype” with Luer and taper fitti
28、ngs, and factory fitted filtermedia. The filter, as shown in Fig. 2, is used with an adaptor(6.9) to allow the test portion to input through the taper fittingand exit from the Luer fitting. The filter medium is supportedby a coarse glass fiber support pad as shown in Fig. 2.6.2.2.2 Filter Media, gla
29、ss fiber grade GF/A, 1.6 m nomi-nal pore diameter and effective filtration area of 95.0 to113.1 mm2. The filters shall be batch selected (one or morefilters from a batch are tested) and quality controlled (using aprocedure and a fluid with a known pressure/flowcharacteristic, for example, ISO 5636-5
30、) for equivalence withthe assembled Filter A.6.2.3 Filter C,7for Procedure C.6.2.3.1 Filter Housing, disposable polypropylene “syringetype” filter housing, as shown in Fig. 3, which has Luer andtaper fittings, and factory fitted filter media. The test portioninputs via the Luer fitting. The filter m
31、edium is held aboveconcentric/segmented ribbed channels and the exit port isrecessed and segmented to eliminate localized filter blocking.6.2.3.2 Filter Media, nylon, 5 m nominal pore diameterand effective filtration area of 143.2 to 165.2 mm2. The filtersshall be batch selected (one or more filters
32、 from a batch aretested) and quality controlled (using a procedure and a fluidwith a known pressure/flow characteristic, for example, ISO5636-5).5The sole source of supply of the Filter A housing, known to the committee atthis time is Millipore Cat No XX3001200, available from Millipore CorporationH
33、eadquarters, 290 Concord Road, Billerica, MA 01821. If you are aware ofalternative suppliers, please supply this information to ASTM International Head-quarters. Your comments will receive careful consideration by a meeting of theresponsible technical committee,1which you may attend.6Whatman Grade G
34、F/A, has been found satisfactory for this purpose.7The following equipment, as listed in RRSR: IP 387/07 (see Footnote 10), wasused to develop the precision statements; Seta MFT Multi Filtration Tester partnumber 91600, Filter capsule “B” part number 91616-001 and Filter capsule “C”part number 91620
35、. Stanhope-Seta, Chertsey, Surrey, KT16 8AP, UK. This is not anendorsement or certification by ASTM.D2068 12a26.3 Measuring Cylinder, 25 mL, glass or other suitabletransparent material, with graduations every 0.5 mL, forverifying the flow rate.6.4 Measuring Cylinder, 500 mL, glass or other suitablet
36、ransparent material, with graduations every 5 mL, for verify-ing the flow rate, and for measuring the volume of fuel in thefuel receiver if required.6.5 Stopwatch, capable of measuring to the nearest 0.2 s,required for verifying the flow rate and preparing the sample.6.6 Thermometer, electronic or l
37、iquid in glass type ther-mometers with a range of at least 15 to 25C and an accuracyof 6 0.5C or better are suitable.6.7 Forceps, spade ended, for use with Filter A.6.8 Open-ended Spanner Wrenches, plastic or metal, for usewith Filter A.6.9 Adaptor, only for use with Procedure B, to convert theLuer
38、fitting on the apparatus to a fitting compatible with thetapered fitting on Filter B.6.10 Anti-splash Tubing, nylon or silicone rubber, approxi-mately 4 mm inner diameter for Filters A and C, and 6 mminner diameter for Filter B, to reduce splashing of the samplein the fuel receiver beaker.7. Samplin
39、g7.1 Unless otherwise specified, samples shall be obtained inaccordance with Practices D4057, D4177 or other comparablesampling practices.7.1.1 Containers shall have been previously flushed threetimes with the product to be sampled.FIG. 1 Assembly of Filter AFIG. 2 Filter BFIG. 3 Filter CD2068 12a37
40、.2 Obtain at least 400 mL of a representative aliquot of thesample to be tested in an epoxy-lined can or dark glass bottle.7.3 If any undissolved water is visually apparent (as deter-mined by Test Methods D4176 or D4860), discard and replacewith a fresh sample.8. Preparation of Apparatus8.1 Verifica
41、tion:8.1.1 Pressure and TemperatureFollow the manufactur-ers instructions for verifying that the pressure and temperaturereadings are in accordance with the tolerances given in A1.1.3and 6.6 respectively. Verify the pressure reading, at ambientatmospheric pressure (0 kPa) and at approximately 100 kP
42、a, atleast every 6 months or if the apparatus has not been used forthe previous 3 months. Verify the temperature reading iscorrect, at ambient temperature, at least every 12 months. If thereadings do not meet the specified tolerances in A1.1.3 and 6.6,calibrate the sensors (8.2.1).8.1.2 Flow RateFol
43、low the manufacturers instructionsfor verifying that the flow rate is 20 6 1 mL/min through afilter assembly. The flow rate is verified by measuring thevolume pumped during a 15 minute period, at least once amonth, using a suitable measuring cylinder (6.4). If themeasured volume is between 285 and 3
44、15 mL the flow rate iscorrect. More frequent checks on the flow rate may be made bymeasuring the volume during a 1 minute period using a 25 mLmeasuring cylinder (6.3). If the measured volume is notbetween 19 and 21 mL, calibrate the pump (8.2.2).8.2 Calibration:8.2.1 Pressure and TemperatureFollow t
45、he manufactur-ers instructions to calibrate the pressure at atmospheric pres-sure (0 kPa) and approximately 100 kPa, and temperaturemeasuring device at ambient temperature.8.2.2 Flow RateFollow the manufacturers instructions toset and lock the mechanical flow adjustment control on thepump to give a
46、flow rate of 20 6 1 mL/min.8.2.2.1 A filter assembly shall be fitted when the flow rate iscalibrated.8.3 Apparatus AssemblyAssemble the apparatus as shownin Fig. A1.1, without the filter unit connected.8.4 Filter AssemblyAssemble the filter appropriate to thetest procedure specified.8.4.1 Filter A (
47、for Procedure A)Assemble the filter asshown in Fig. 1 using a new filter medium handled with theforceps (6.7) taking care not to damage the filter medium. Placethe medium into the holder with the face marked with a gridpattern uppermost. The open ended spanner wrenches (6.8)may be used to assist in
48、assembling or disassembling thehousing. Attach a suitable length (typically 80 to 90 mm) ofanti-splash tubing (6.10) to the outlet of the filter assembly.NOTE 3It is most important that the filter unit components areassembled in the exact configuration shown in Fig. 1.NOTE 4Over- or under-tightening
49、 of the Filter A assembly can lead toerroneous results.8.4.2 Filter B (for Procedure B)Attach a suitable length(typically 80 to 90 mm) of anti-splash tubing (6.10)totheoutlet of the filter assembly.8.4.2.1 Attach the adaptor (6.9) to the Luer fitting on theoutlet of the apparatus.8.4.3 Filter C ( for Procedure C)Attach a suitable length(typically 80 to 90 mm) of anti-splash tubing (6.10)totheoutlet of the filter assembly.8.5 Rinse the fuel reservoir beaker with some of the productto be tested, and discard.8.6 Remove the adaptor if Procedures A or C a
