1、Designation: D4625 16Designation: 378/87Standard Test Method forMiddle Distillate Fuel Storage Stability at 43 C (110 F)1This standard is issued under the fixed designation D4625; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、 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.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope*1.1 This test method cover
3、s a method for evaluating theinherent storage stability of distillate fuels having flash pointsabove 38 C (100 F), by Test Methods D93, and 90 % distilledpoints below 340 C (644 F), by Test Method D86.NOTE 1ASTM specification fuels falling within the scope of this testmethod are Specification D396,
4、Grade Nos. 1 and 2; Specification D975,Grades 1-D and 2-D; and Specification D2880, 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 storagetemperatures.1.3 App
5、endix X1 presents additional information aboutstorage stability and the correlation of Test Method D4625results with sediment formation in actual field storage.1.4 The values given in SI units are to be regarded as thestandard.1.4.1 ExceptionThe values in parentheses are for informa-tion only.1.5 Th
6、is 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 limitations prior to use.2. Referenced Documen
7、ts2.1 ASTM Standards:2D86 Test Method for Distillation of Petroleum Products andLiquid Fuels at Atmospheric PressureD93 Test Methods for Flash Point by Pensky-MartensClosed Cup TesterD381 Test Method for Gum Content in Fuels by Jet Evapo-rationD396 Specification for Fuel OilsD975 Specification for D
8、iesel Fuel OilsD1193 Specification for Reagent WaterD2880 Specification for Gas Turbine Fuel OilsD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum Products3. Terminology3.1 Definitions of Terms Specific to This Standa
9、rd:3.1.1 adherent insolubles, ngums formed during storagethat remain tightly attached to the walls of the vessel after fuelhas been flushed from the container.3.1.2 filterable insolubles, nsolids formed during storagethat can be removed from the fuel by filtration.3.1.3 inherent storage stability, n
10、of middle distillatefuelthe resistance of the fuel to change during storage incontact with air, but in the absence of other environmentalfactors such as water, or reactive metals and dirt.3.1.4 total insolubles, nthe arithmetic sum of the filterableinsolubles plus the adherent insolubles.4. Summary
11、of Test Method4.1 Four-hundred (400) mLvolumes of filtered fuel are agedby storage in borosilicate glass containers at 43 C (110 F) forperiods of 4, 8, 12, 18, and 24 weeks. If desired, performzero-week analyses on the same day as the other samples areplaced in storage. Zero-week data are used to pr
12、ovide base dataand ensure satisfactory technique. After aging for a selectedtime period, a sample is removed from storage, cooled to roomtemperature, and analyzed for filterable insolubles and foradherent insolubles.5. Significance and Use5.1 Fuel oxidation and other degradative reactions leadingto
13、formation of sediment (and color) are mildly accelerated by1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricantsand is the direct responsibility ofSubcommittee D02.14 on Stability and Cleanliness of Liquid Fuels.Current edition approved
14、Dec. 1, 2016. Published January 2017. Originallyapproved in 1986. Last previous edition approved in 2014 as D4625 14. DOI:10.1520/D4625-16.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 Se
15、rvice 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 this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 1942
16、8-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Techni
17、cal Barriers to Trade (TBT) Committee.1the 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.5.2
18、 Because the storage periods are long (4 weeks to24 weeks), the test method is not suitable for quality controltesting, but does provide a tool for research on storageproperties of fuels.5.3 Because environmental effects and the materials andnature of tank construction affect storage stability, the
19、resultsobtained by this test are not necessarily the same as thoseobtained during storage in a specific field storage situation.6. Apparatus6.1 Sample Containers, borosilicate glass bottles, nominalcapacity 500 mL (Fig. 1). The containers shall have a cap, lid,or cover, preferably with a polytetrafl
20、uoroethylene (PTFE)insert and a hole for a borosilicate glass vent.6.2 Storage Oven, large enough to contain all of the samplebottles. The oven shall be thermostatically controlled to main-tain a temperature of 43 C 6 1C(110F6 2 F). It shall beas dark as possible to prevent degradation due to photol
21、yticreactions and shall also be explosion proof.6.3 Filter Drying Oven, shall be capable of safely evapo-rating the solvent at 90 C 6 5 C for the drying of filters.6.4 Filtration SystemArrange the following componentsas shown in Fig. 2.6.4.1 Funnel and Funnel Base, with filter support for a47 mm dia
22、meter membrane and a locking ring or spring actionclip.6.4.2 Ground/Bond Wire, 0.912 mm to 2.59 mm (No. 10 toNo. 19) bare-stranded, flexible stainless steel or copper in-stalled in the flasks and grounded as shown in Fig. 2.6.4.3 Receiving Flask, 1.5 L, or larger, borosilicate glassvacuum filter fla
23、sk, into which the filtration apparatus fits,equipped with a sidearm to connect to the safety flask.6.4.4 Safety Flask, 1.5 L, or larger, borosilicate glassvacuum filter flask equipped with a sidearm to connect thevacuum system. A fuel and solvent resistant rubber hose,through which the grounding wi
24、re passes, shall connect thesidearm of the receiving flask to the tube passing through therubber stopper in the top of the safety flask.6.4.5 Vacuum System, either a water-aspirated, or amechanical, vacuum pump may be used if capable of produc-ing a vacuum of 80 kPa to 100 kPa below atmospheric pres
25、surewhen measured at the receiving flask.7. Reagents and Materials7.1 Purity of ReagentsReagent grade chemicals shall beused 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
26、 wheresuch specifications are available.3Other grades may be used,provided it is first ascertained that the reagent is of 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.
27、8 m. (Membrane filterswith a grid imprinted on their surface may be used as controlmembrane filters for identification.)7.3 Hydrocarbon Solvent, 2,2,4-trimethylpentane (iso-octane)ASTM knock test reference fuel grade or equivalent,prefiltered through two glass-fiber or nylon membrane filters,nominal
28、 pore size 0.8 m. (WarningExtremely flammable.Harmful if inhaled. Vapors may cause flash fire.)7.4 Adherent Insolubles Solvent (WarningExtremelyflammable. Vapors harmful. May cause flash fire)Mix equalvolumes of reagent grade acetone (WarningExtremely flam-mable. Vapors may cause flash fire), methyl
29、 alcohol(WarningFlammable. Vapor harmful. May be fatal or causeblindness if swallowed or inhaled. Cannot be madenonpoisonous), and toluene (WarningFlammable. Vaporharmful.).7.5 Purity of WaterUnless otherwise indicated, referencesto water mean reagent water as defined by Type III ofSpecification D11
30、93.7.6 Liquid or Powder Detergent, water-soluble, for cleaningglassware.8. Sampling Procedure8.1 Samples for testing shall be obtained by an appropriatemethod outlined in Practice D4057 or D4177. Sample contain-ers should be 1 gal (3.78 L) or larger, epoxy-lined cans. Fill3Reagent Chemicals, America
31、n 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 United States Pharmacopeiaand National Formulary, U
32、.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.FIG. 1 Sample Storage ContainerD4625 162sample cans almost to the top to avoid a significant air space.Purge the void space with nitrogen. Store the samples atreduced temperature, 7 C to 4 C (20 F to 40 F), prior touse, where possible.9. Prepar
33、ation of Apparatus and Sample Bottles9.1 Sample Storage BottlesScrub each bottle and cap witha detergent solution and rinse it with water. Soak the bottle andcap overnight in an alkaline laboratory glassware cleaningsolution. Rinse the bottle and cap with tap water, then invertthem and flush them wi
34、th a stream of distilled water. Allow thebottles and caps to dry. Prior to introducing the sample, rinsethe bottles with 50 mL of the fuel sample. Vent the bottlesduring storage, using a glass tube bent in an upside down “U,”(see Fig. 1), to prevent contamination of the sample fromairborne particula
35、tes. Insert the glass tube through a cover,preferably equipped with a polytetrafluoroethylene (PTFE)insert (see Fig. 1).9.2 Clean all components of the filtration apparatus asdescribed in 9.2.1 9.2.7.9.2.1 Remove any labels, tags, and so forth.9.2.2 Wash with warm tap water containing detergent.9.2.
36、3 Rinse thoroughly with warm tap water.9.2.4 Rinse thoroughly with deionized water.9.2.5 Rinse thoroughly 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 rinsedwi
37、th filtered flushing fluid) over the top of the sample containeruntil the cap is installed. Similarly, protect 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 t
38、est membranefilter and one control membrane filter. For fuels containinglittle particulate materials, only 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 mark
39、ing the petri dishesused to hold and transport the filters. Clean all glassware usedin preparation of membrane 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
40、clean glass support rods, orwatch glasses, in the petri dish.9.3.1.2 Place the petri dish, with its lid slightly ajar, in adrying oven at 90 C 6 5 C 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 su
41、ch that the membrane filters are still protected fromcontamination from the atmosphere. Allow 30 min for themembrane 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
42、 itcentrally on the weighing pan of the balance. Weigh it, recordthe initial mass to the nearest 0.1 mg, and 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 o
43、f thefiltration apparatus (see Fig. 2). Place the weighed test mem-brane filter on top of the control membrane 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
44、the fuel has been stored at reduced temperature,allow the sample to come to ambient temperature. To dissolveany separated wax, be certain that the entire fuel sample is atleast 5 C above its cloud point before proceeding.10.2 The test fuel shall be filtered prior to placing it instorage. Assemble a
45、filtration system, as shown in Fig. 2,tofilter the fuel. Use a single membrane filter for this filtrationstep. This membrane filter need not be preweighed.10.3 Using this filtration assembly, filter sufficient fuel toput 400 mL of fuel in each storage bottle. For a typical test, thisis 4 L of fuel.
46、It is prudent to filter a small amount of extra fuel.It may be necessary to replace the filter membrane (7.2)throughout this step, depending on the cleanliness of the testfuel.FIG. 2 Schematic of Filtration SystemD4625 16311. Procedure11.1 Sample Aging:11.1.1 Adjust the storage oven for sample stora
47、ge to atemperature of 43 C 6 1C(110F6 2 F).11.1.2 Place 400 mL of filtered fuel into each bottle. Usetwo bottles for each sampling period. (Commonly used sam-pling periods are 4, 8, 12, 18, and 24 weeks). Extra bottles maybe placed in storage to be used in case of accidents, for furthertests at othe
48、r times of storage, or to extend the overall testduration.11.1.2.1 Some operators have found it useful to conduct azero-week test as a demonstration of proper technique. Sincethe fuel is prefiltered, zero-week results should be nil. Azero-week analysis is not a mandatory part of the analysis.11.1.3
49、Label each storage bottle with the time and date thetest is started, sample identification, and the time and datewhen the bottle is to be removed from storage. Place the bottlesin the oven in random order as a means to reduce the possibleeffects of hot zones in the oven.11.2 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 to21 C to 27 C (70 F to 80 F) in a dark environment. Thismay take from 4 h to 24 h.11.2.2 Assemble the
