1、Designation: D 4625 04Designation: 378/87An American National StandardStandard Test Method forMiddle Distillate Fuel Storage Stability at 43C (110F)1This standard is issued under the fixed designation D 4625; the number immediately following the designation indicates the year oforiginal adoption or,
2、 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.1. Scope*1
3、.1 This test method covers a method for evaluating theinherent storage stability of distillate fuels having flash pointsabove 38C (100F), by Test Methods D 93, and 90 % distilledpoints below 340C (644F), by Test Method D 86.NOTE 1ASTM specification fuels falling within the scope of this testmethod a
4、re Specification D 396, Grade Nos. 1 and 2; Specification D 975,Grades 1-D and 2-D; and Specification D 2880, Grades 1-GT and 2-GT.1.2 This test method is not suitable for quality controltesting but, rather it is intended for research use to shortenstorage time relative to that required at ambient s
5、toragetemperatures.1.3 Appendix X1 presents additional information aboutstorage stability and the correlation of Test Method D 4625results with sediment formation in actual field storage.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is t
6、heresponsibility 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.2. Referenced Documents2.1 ASTM Standards:2D 86 Test Method for Distillation of Petroleum Products atAtmospheric PressureD 93 Te
7、st Methods for Flash-Point by Pensky-MartensClosed Cup TesterD 381 Test Method for Gum Content in Fuels by JetEvaporationD 396 Specification for Fuel OilsD 975 Specification for Diesel Fuel OilsD 1193 Specification for Reagent WaterD 2880 Specification for Gas Turbine Fuel OilsD 4057 Practice for Ma
8、nual Sampling of Petroleum andPetroleum ProductsD 4177 Practice for Automatic Sampling of Petroleum andPetroleum Products3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 adherent insolubles, ngums formed during storagethat remain tightly attached to the walls of the vessel.3.1.
9、2 filterable insolubles, nsolids formed during storagethat can be removed from the fuel by filtration.3.1.3 inherent storage stability, nof middle distillatefuelthe resistance to change in storage in contact with air, butin the absence of other environmental factors such as water, orreactive metalli
10、c surfaces and dirt.3.1.4 total insolubles, nsum of the filterable insolublesplus the adherent insolubles.4. Summary of Test Method4.1 Four-hundred millilitre volumes of filtered fuel are agedby storage in borosilicate glass containers at 43C (110F) forperiods of 0, 4, 8, 12, 18, and 24 weeks. After
11、 aging for aselected time period, a sample is removed from storage, cooledto room temperature, and analyzed for filterable insolubles andfor adherent insolubles.5. Significance and Use5.1 Fuel oxidation and other degradative reactions leadingto formation of sediment (and color) are mildly accelerate
12、d bythe test conditions compared with typical storage conditions.Test results have been shown to predict storage stability morereliably than other more accelerated tests. See Appendix X1 forinformation on the correlation of test results with actual fieldstorage.1This test method is under the jurisdi
13、ction 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 June 1, 2004. Published July 2004. Originally approvedin 1986. Last previous edition approved in 2003 as D 4625
14、03.This test method was adopted as a joint ASTM/IP standard in 1986.2For 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 w
15、ebsite.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.5.2 Because the storage periods are long (4 to 24 weeks), thetest method is not suitable for quality control tes
16、ting, but doesprovide a tool for research on storage properties of fuels.5.3 Because environmental effects and the materials andnature of tank construction affect storage stability, the resultsobtained by this test are not necessarily the same as thoseobtained during storage in a specific field stor
17、age situation.6. Apparatus6.1 Sample Containers, borosilicate glass bottles. The con-tainers must have a lid or cover, preferably with a polytet-rafluoroethylene (PTFE) insert and a hole for a borosilicateglass vent. The total capacity of the containers is 500 mL.6.2 Storage Oven, large enough to co
18、ntain all of the samplebottles. The oven shall be thermostatically controlled to main-tain a temperature of 43 6 1C (110 6 2F). It shall be as darkas possible to prevent degradation due to photolytic reactionsand shall also be explosion proof.6.3 Filter Drying Oven, shall be capable of safely evapo-
19、rating the solvent at 90 6 5C for the drying of filter materials.6.4 Filtration SystemArrange the following componentsas shown in Fig. 1.6.4.1 Funnel and Funnel Base, with filter support for a47-mm diameter membrane and a locking ring or spring actionclip.6.4.2 Ground/Bond Wire, 0.9122.59 mm (No. 10
20、No. 19)bare-stranded, flexible stainless steel or copper installed in theflasks and grounded as shown in Fig. 1.6.4.3 Receiving Flask, 1.5 L or larger borosilicate glassvacuum filter flask, which the filtration apparatus fits into,equipped with a sidearm to connect to the safety flask.6.4.4 Safety F
21、lask, 1.5 L or larger borosilicate glass vacuumfilter flask equipped with a sidearm to connect the vacuumsystem. A fuel and solvent resistance rubber hose, throughwhich the grounding wire passes, shall connect the sidearm ofthe receiving flask to the tube passing through the rubberstopper in the top
22、 of the safety flask.6.4.5 Vacuum System, either a water-aspirated or a mechani-cal vacuum pump may be used if capable of producing avacuum of up to 100 kPa below atmospheric pressure whenmeasured at the receiving flask.7. Reagents and Materials7.1 Purity of ReagentsReagent grade chemicals shall beu
23、sed in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.3Other grades may be used,provided it is first ascertained that the reagent is of
24、 sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.7.2 Nylon Test and Control Membrane Filtersplain,47-mm diameter, nominal pore size 0.8-m. (Membrane filterswith a grid imprinted on their surface may be used as controlmembrane filters for identification.)7
25、.3 Hydrocarbon Solvent, 2,2,4-trimethylpentane (iso-octane)ASTM knock test reference fuel grade, prefilteredthrough two glass-fiber filters. (WarningExtremely flam-mable. Harmful if inhaled. Vapors may cause flash fire.)7.4 Adherent Insolubles Solvent (WarningExtremelyflammable. Vapors harmful. May
26、cause flash fire)Mix equalvolumes of reagent grade acetone (WarningExtremely flam-mable. Vapors may cause flash fire), methyl alcohol(WarningFlammable. Vapor harmful. May be fatal or causeblindness if swallowed or inhaled. Cannot be made nonpoison-ous), and toluene (WarningFlammable. Vapor harmful.)
27、.7.5 Purity of WaterUnless otherwise indicated, referencesto water mean reagent water as defined by Type III ofSpecification D 1193.7.6 Liquid or Powder Detergent, water-soluble, for cleaningglassware.8. Sampling Procedure8.1 Samples for testing shall be obtained by an appropriatemethod outlined in
28、Practice D 4057 or D 4177. Sample con-tainers should be 1 gal (3.78 L) or larger, epoxy-lined cans. Fillsample cans almost to the top to avoid a significant air space.3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testin
29、g of reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.FIG. 1 Schematic of Filtration SystemD4625042Purge
30、 the void space with nitrogen. Store the samples atreduced temperature, -7 to 4C (20 to 40F), prior to use, wherepossible.9. Preparation of Apparatus and Sample Bottles9.1 Sample Storage BottlesScrub each bottle with a de-tergent solution and rinse it with water. Soak the bottleovernight in a mildly
31、 alkaline laboratory glassware cleaningsolution. Rinse the bottle with tap water, then invert it and flushit with a stream of distilled water. Allow the bottles to dry andrinse the bottles with 50 mL of the fuel sample. Vent the bottlesduring storage, using a glass tube bent in an upside down “U,”(s
32、ee Fig. 2), to prevent contamination of the sample fromairborne particulates. Insert the glass tube through a cover,preferably equipped with a polytetrafluoroethylene (PTFE)insert (see Fig. 2).9.2 Clean all components of the filtration apparatus asdescribed in 9.2.1-9.2.7.9.2.1 Remove any labels, ta
33、gs, and so forth.9.2.2 Wash with warm tap water containing detergent.9.2.3 Rinse thoroughly with warm tap water.9.2.4 Rinse thoroughly with deionized water. Containercaps should be handled only externally with clean laboratorycrucible tongs during this and subsequent washings.9.2.5 Rinse thoroughly
34、with propan-2-ol that has beenfiltered through a 0.45-m membrane filter.9.2.6 Rinse thoroughly with filtered flushing fluid and dry.9.2.7 Keep a clean protective cover (the cover may be rinsedwith filtered flushing fluid) over the top of the sample containeruntil the cap is installed. Similarly, pro
35、tect the funnel openingof the assembled filtration apparatus with a clean protectivecover until ready for use.9.3 Preparation of Membrane Filters:9.3.1 Each set of test filters consists of one test membranefilter and one control membrane filter. For fuels containinglittle particulate materials, only
36、 one set of filters is required. Ifthe fuel is highly contaminated, more than one set of filtersmay be required. The two membrane filters used for eachindividual test shall be identified by marking the petri dishesused to hold and transport the filters. Clean all glassware usedin preparation of memb
37、rane filters as described in 9.2.9.3.1.1 Using forceps, place the test and control membranefilters side by side in a clean petri dish. To facilitate handling,the membrane filters should rest on clean glass support rods, orwatch glasses, in the petri dish.9.3.1.2 Place the petri dish, with its lid sl
38、ightly ajar, in adrying oven at 90 6 5C and leave it for 30 min.9.3.1.3 Remove the petri dish from the drying oven, andplace it near the balance. Keep the petri dish cover ajar, butkeep it such that the membrane filters are still protected fromcontamination from the atmosphere. Allow 30 min for them
39、embrane filters to come to equilibrium with room air tem-perature and humidity.9.3.1.4 Remove the control membrane filter from the petridish with forceps, handling by the edge only, and place itcentrally on the weighing pan of the balance. Weigh it, recordthe initial mass to the nearest 0.0001 g, an
40、d return it to the petridish.9.3.1.5 Repeat 9.3.1.4 for the test membrane filter.9.3.1.6 Using clean forceps, place the weighed controlmembrane filter centrally on the membrane filter support of thefiltration apparatus (see Fig. 1). Place the weighed test mem-brane filter on top of the control membr
41、ane filter. Install thefunnel and secure with locking ring or spring clip. Do notremove the plastic film from the funnel opening until ready tostart filtration.10. Preparation of Sample10.1 If the fuel has been stored at reduced temperature,allow the sample to come to ambient temperature. To dissolv
42、eany separated wax, be certain that the entire fuel sample is atleast 5C above its cloud point before proceeding.10.2 Assemble a filtration system, as shown in Fig. 1, tofilter the fuel. Clean the receiving flask, separatory funnel, andglass funnel in the same manner as the storage bottles (9.1).Rin
43、se these items with filtered isooctane and then air.11. Procedure11.1 Sample Aging:11.1.1 Adjust the storage oven for sample storage to atemperature of 43 6 1C (110 6 2F).11.1.2 Place 400 mL of filtered fuel into each bottle. Usetwo bottles for each sampling period. (Commonly used sam-pling periods
44、are 0, or any of the following: 4, 8, 12, and 24weeks). Fill three extra bottles with fuel to be used in case ofaccidents, for further tests at other times of storage, or toextend the overall test duration.11.1.3 Label each storage bottle with the time and date thetest is started, sample identificat
45、ion, and the time and datewhen the bottle is to be removed from storage. Place the bottlesin the oven in random order.11.1.4 Perform zero-week analyses on the same day as theother samples are placed in storage. Zero-week data arenecessary to provide base data and assure satisfactory tech-nique.FIG.
46、2 Sample Storage ContainerD462504311.2 Determination of Filterable Insolubles:11.2.1 At the end of each prescribed period of time, removetwo bottles from the storage oven and allow them to cool to 21to 27C (70 to 80F) in a dark environment. This may takefrom4to24h.11.2.2 After cooling, pour fuel fro
47、m the sample container tothe graduated cylinder, start the vacuum, and then transfer 100mL of fuel to the filter funnel.11.2.2.1 Continue transferring 100-mL increments of fuel tothe filter funnel. When all the fuel from the sample containerhas been filtered, or if filtration slows so that 100 mL of
48、 samplerequires greater than 10 min for complete filtration, thenremove the filter support/filter funnel from the receiving flask,pour the filtered fuel into a clean graduated cylinder, and recordthe volume of fuel that was filtered in millilitres. Keep the fuelsample filtrate separate from the solv
49、ent washings filtrate. Thisallows the fuel to be used for additional analyses. If all the fuelhas been filtered, thoroughly rinse the sample container and thegraduated cylinder with one or more portions of filteredflushing fluid, pour the rinses into the funnel, and proceed to11.2.2.2. If all the fuel has not been filtered, proceed to 11.2.2.2and 11.2.2.3, and then repeat from 11.2.2.1.11.2.2.2 Wash down the inside of the funnel and the outsideof the joint between the funnel and filter base filtered withflushing fluid. With the vacuum applied,
