1、Designation: D4625 14Designation: 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. The values in parentheses are for information only.1.5 This standard doe
6、s 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 Documents2.1 ASTM Stan
7、dards:2D86 Test Method for Distillation of Petroleum Products atAtmospheric 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 Diesel Fuel OilsD1193 Specificati
8、on 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 Standard:3.1.1 adherent insolubles, ng
9、ums 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, nof middle distillatefuelthe resi
10、stance 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 of Test Method4.1 Four-hundred m
11、illilitre volumes of filtered fuel are agedby storage in borosilicate glass containers at 43 C (110 F) forperiods of (0, 4, 8, 12, 18, 24) weeks.After aging for a selectedtime period, a sample is removed from storage, cooled to roomtemperature, and analyzed for filterable insolubles and foradherent
12、insolubles.5. Significance and Use5.1 Fuel oxidation and other degradative reactions leadingto formation of sediment (and color) are mildly accelerated bythe test conditions compared with typical storage conditions.Test results have been shown to predict storage stability morereliably than other mor
13、e accelerated tests. See Appendix X1 forinformation on the correlation of test results with actual fieldstorage.1This 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
14、Cleanliness of Liquid Fuels.Current edition approved Dec. 1, 2014. Published March 2015. Originallyapproved in 1986. Last previous edition approved in 2009 as D4625 04 (2009).This test method was adopted as a joint ASTM/IP standard in 1986. DOI:10.1520/D4625-14.2For referenced ASTM standards, visit
15、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 this standardCopyright ASTM International, 100
16、Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.2 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 effe
17、cts 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 storage situation.6. Apparatus6.1 Sample Containers, borosilicate glass bottles. The con-tainers must have
18、a lid or cover, preferably with a polytetra-fluoroethylene (PTFE) insert and a hole for a borosilicate glassvent. The total capacity of the containers is 500 mL.6.2 Storage Oven, large enough to contain all of the samplebottles. The oven shall be thermostatically controlled to main-tain a temperatur
19、e of 43 C 6 1C(110F6 2 F). It shall beas dark as possible to prevent degradation due to photolyticreactions 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 filtermaterials.6.4 Filtration SystemArrange the f
20、ollowing 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, 0.912 mm to 2.59 mm (No. 10 toNo. 19) bare-stranded, flexible stainless steel or copper in-stalled in the flasks and gr
21、ounded 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 Flask, 1.5 L or larger borosilicate glass vacuumfilter flask equipped with a sidearm to
22、 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 of the safety flask.6.4.5 Vacuum System, either a water-aspirated or a mechani-cal va
23、cuum 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 beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform
24、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 sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determ
25、ination.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.)7.3 Hydrocarbon Solvent, 2,2,4-trimethylpentane (iso-octane)ASTM knock test reference f
26、uel 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 cause flash fire)Mix equalvolumes of reagent grade acetone (WarningExtremely flam-mabl
27、e. Vapors may cause flash fire), methyl 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
28、defined by Type III ofSpecification D1193.7.6 Liquid or Powder Detergent, water-soluble, for cleaningglassware.3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society
29、, 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 SystemD4625 1428. Sampling Procedure8.1 Samples for testing shall be obtain
30、ed by an appropriatemethod outlined in Practice D4057 or D4177. Sample contain-ers should be 1 gal (3.78 L) or larger, epoxy-lined cans. Fillsample 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
31、 40 F), prior touse, where possible.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 alkaline laboratory glassware cleaningsolution. Rinse the bottle with tap water, then
32、 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,”(see Fig. 2), to prevent contamination of the sample fromairborne particulates. Insert t
33、he 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, tags, and so forth.9.2.2 Wash with warm tap water containing detergent.9.2.3 Rinse thoro
34、ughly 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 with propan-2-ol that has beenfiltered through a 0.45 m membrane filter.9.2.6 Rinse th
35、oroughly 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, protect the funnel openingof the assembled filtration apparatus with a clean protectiveco
36、ver 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 one set of filters is required. Ifthe fuel is highly contaminated, more than one set
37、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 membrane filters as described in 9.2.9.3.1.1 Using forceps, place the test and control mem
38、branefilters 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 slightly ajar, in adrying oven at 90 C 6 5 C and leave it for 30 min.9.3.1.3 Remove the
39、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 themembrane filters to come to equilibrium with room air tem-perature and humidity.9.3.
40、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, and return it to the petridish.9.3.1.5 Repeat 9.3.1.4 for the test membrane filter.9.
41、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 membrane filter. Install thefunnel and secure with locking ring or spring clip. Do notre
42、move 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 dissolveany separated wax, be certain that the entire fuel sample is atleast 5 C above its
43、 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).Rinse these items with filtered isooctane and then air.11. Procedure11.1 Sample Aging:
44、11.1.1 Adjust the storage oven for sample storage 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 0 weeks, or any of the following: (4, 8, 12,24) weeks). Fill three extra bott
45、les with fuel to be used in caseof accidents, for further tests at other times of storage, or toextend the overall test duration.FIG. 2 Sample Storage ContainerD4625 14311.1.3 Label each storage bottle with the time and date thetest is started, sample identification, and the time and datewhen the bo
46、ttle 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.11.2 Determination of Filterable Insoluble
47、s: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 After cooling, pour fuel from the sample container tothe graduated cylinder, start the vacuu
48、m, and then transfer100 mL 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 samplerequires greater than 10 min for complete filtration, the
49、nremove 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 solvent 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 f
