1、Designation: D6986 03 (Reapproved 2016) An American National StandardStandard Test Method forFree Water, Particulate and Other Contamination in AviationFuels (Visual Inspection Procedures)1This standard is issued under the fixed designation D6986; the number immediately following the designation ind
2、icates the year oforiginal adoption or, in the case of revision, the 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.INTRODUCTIONFuel quality is paramount in aviation fue
3、ls because of their critical application. Many successivetypes of inspections are conducted to ensure quality protection. Rapid, visual inspections carried outat various locations in the fuel supply system are a critical part of the inspection program. Experiencehas shown that subjective evaluations
4、 such as described by this test method form an effective field alertsystem that is backed by other, more quantitative tests.The present test method duplicates much of Test Method D4176, a test method applicable to alldistillate fuels. However, the present test method also includes field methods appl
5、icable especially toaviation fuels, and is therefore published as a separate test method.1. Scope1.1 This test method covers two procedures for establishingthe presence of suspended free water, solid particulate, andother contaminants in aviation gasoline and aviation turbinefuels.1.1.1 Both procedu
6、res are intended primarily for use as fieldtests with the fuel at handling temperature.1.1.2 Procedure A uses transparent sample containers; Pro-cedure B uses opaque containers.1.2 Both procedures are rapid methods for contaminationdetection and include ratings of haze appearance and particu-late pr
7、esence.1.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.2. Referenced Documents2.1 ASTM Standards:2D2276 Test Method for Particulate Contaminant in AviationFuel by Line SamplingD3240 Test Method for Undissolved Water In Avia
8、tionTurbine FuelsD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4176 Test Method for Free Water and Particulate Contami-nation in Distillate Fuels (Visual Inspection Procedures)D5452 Test Method for Particulate Contamination in Avia-tion Fuels by Laboratory Filtration2.2 ASTM
9、Adjuncts:ADJD417601 Distillate Fuel Bar Chart3ADJD417602 Distillate Fuel Haze Rating Standard43. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 aviation fuelsas used in this standard, the termincludes both aviation gasoline and aviation turbine fuels.3.1.2 clear and brighta cond
10、ition in which the fuelcontains no visible water drops or particulates and is free ofhaze or cloudiness.3.1.3 free waterwater in excess to that soluble in the fuelat the temperature of the test and may appear in the fuel as ahaze, cloudiness, droplets, or water layer.3.1.4 solid particulatessmall so
11、lid or semi-solid particles,sometimes referred to as silt or sediment, present in a fuel asthe result of contamination by airborne dusts, corrosion by-products, or wear products.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and i
12、s the direct responsibility ofSubcommittee D02.J0 on Aviation Fuels.Current edition approved Oct. 1, 2016. Published November 2016. Originallypublished in 2003. Last previous edition approved in 2010 as D6986 03 (2010).DOI: 10.1520/D6986-03R16.2For referenced ASTM standards, visit the ASTM website,
13、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 ASTM International Headquarters. Order Adjunct No.ADJD417601.4Available from ASTM International Headq
14、uarters. Order Adjunct No.ADJD417602.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Summary of Test Method4.1 The test method describes two types of sampling con-tainers for evaluating the appearance of aviation fuel samples.Proce
15、dure A covers transparent sample containers, includingthe open jar and the closed circuit sampler, while Procedure Buses opaque containers such as the white bucket.4.2 In the open jar procedure, a minimum of 750 mL (24 oz)of fuel is placed into a clear one litre (1 qt) container andexamined visually
16、. The jar is then closed and the sample isswirled and examined for visual sediment and water at thebottom of the vortex. Additionally, fuel clarity may be rated byplacing a standard bar chart behind the sample and comparingits visual appearance with the standard haze rating photo-graphs. The presenc
17、e or absence of free water and of particu-lates is reported.4.3 In the closed circuit sampler procedure, approximately3500 mL (0.9 U.S. gal) of fuel is placed into the sampler and isexamined for clarity and for visual sediment or water dropletson the bottom of the sampler. Additionally, fuel clarity
18、 may berated by placing a standard bar chart behind the sample andcomparing its visual appearance with the standard haze ratingphotographs. The presence or absence of free water and ofparticulates is reported.4.4 In the white bucket procedure fuel to a depth ofapproximately 15 cm (6 in.) is collecte
19、d in a white porcelaincoated or stainless steel bucket. The sample is examined forsolids or sediment, or both, on the bottom of the bucket.Sample clarity can be checked by the appearance of a small,shiny coin on the buckets bottom. If the fuel is dry, the raisedletters on the coin should be easily r
20、eadable. The amount ofsediment can be described by a letter category using a ratingguide.4.5 In both procedures, the sample is inspected for color orother unusual appearance.4.6 Field inspection procedures are performed immediatelyafter sampling at fuel handling temperature conditions.5. Significanc
21、e and Use5.1 The two procedures in the test method provide rapidmethods for field detection of free water and solidcontaminants, or any other visually apparent contamination.Uncertain or marginal results by either of these methods wouldnormally result in the performance of methods such as D2276,D545
22、2,orD3240 for quantitative determination of contami-nants.5.1.1 Particulate determination in appearance tests is sensi-tive to sampling procedures. The presence of a small number ofparticles may indicate, for example, that the sample line wasnot flushed to provide a representative sample. The persis
23、tentpresence of even a small number of particles, however, may because for further investigation depending on the situation.5.2 Experience has shown that an experienced tester using aclear bottle can detect as little as 40 ppm of free, suspendedwater in the fuel. Thus, a fuel rated as clear and brig
24、ht can stillfail lower limits set by quantitative methods. A rater will alsohave difficulty resolving particles smaller than 40 m. Smallerparticles must be determined by other than visual methods suchas D2276, D5452 or chemical field tests listed in Manual 5.55.3 Experience has shown the visual appe
25、arance of fuel in awhite porcelain bucket to be the most suitable method for thedetection of dye contamination or other unusual discoloration.In the U. S., the white porcelain bucket is used to detect thedye.6. Apparatus6.1 Cylindrical Clear Container, such as:6.1.1 Clear Container, with lid, capabl
26、e of holding 750 mL(nominal 1 U.S. qt) of fuel and having a diameter of 100 mm6 10 mm (4 in. 6 0.4 in.). There should be no gasket in the lid.6.1.2 Closed Circuit Sampler, holding about 4 L (1 gal U.S.)of fuel and being permanently mounted to receive fuel from afuel line or a storage tank and having
27、 inlet and outlet valves tocontrol filling and emptying of the container. The sampler baseis normally conical and incorporates the fuel inlet and outlet.The fill port is designed to cause the fuel to swirl around thesides of the clear glass tube. The circuit sampler may alsocontain hydrometer and ch
28、emical water detection ports.6.2 Appearance Card and Photographs:6.2.1 Paper Card (Bar Chart), laminated in clear plastichaving five parallel lines of different widths (see ASTMadjunct ADJD417601).6.2.2 Appearance Photographs, a series of standard photo-graphs of the bar chart through a series of sa
29、mples of differenthaze levels, numbered from one through six. Photograph No. 1is the clearest, while No. 6 represents the densest haze (seeASTM adjunct ADJD417602). A fuel sample rated clear andbright will have a rating of “one.”6.2.2.1 The differences between these haze levels are arbi-trary and ar
30、e not intended to represent equivalent increases insuspended water content or particulates. It is essential,therefore, that only the proper approved bar charts and photo-graphs be used.6.3 Opaque Sample Containers:6.3.1 White Bucket, a circular bucket with straight butnon-parallel sides and a flat b
31、ottom and a minimum capacity of7.5 L (2.0 U.S. gal) and approximately 20 cm (8 in.) high,either coated with white porcelain enamel or made of stainlesssteel. Porcelain coatings must be free of dark spots, chips, orother surface damage, most particularly on the bottom of thebucket. Stainless steel bu
32、ckets shall be made of a rust-resistantsteel and have a polished internal surface. The white porcelainbucket should be used for the optimum detection of unusualcoloration.NOTE 1A quantitative description of acceptable white color is inpreparation.NOTE 2Buckets made of white, hard plastic have been f
33、ound to staina yellow color over time, which can make it difficult to observe a haze orcolor changes. The use of plastic containers is also discouraged unlessprovision is made for bonding such containers to the filling line.5Manual 5, Aviation Fuel Quality Control Procedures, 2nd Ed., ASTMInternatio
34、nal, W. Conshohocken, PA, 1995.D6986 03 (2016)26.4 Color and Particle Assessment Rating Guide:66.4.1 This guide contains both a series of photographs ofparticulates of differing concentrations, each having a differentletter rating, and a series of color photographs for rating filtermembranes obtaine
35、d by Test Methods D2276. For this testmethod, only the particle rating scale is used. The particlerating scale does not bear a direct relationship to the mass ofparticulates but is simply a way of communicating the amountof visible particulates in the sample.7. Sampling7.1 Sampling shall be consiste
36、nt with the procedures inPractice D4057.7.2 Draw the sample for a field test directly into the testcontainer using the following procedure:7.2.1 Ensure that the sampling valve is free of loose solidcontaminants. If rust or other loose encrustation is present,remove with a cloth; then flush the sampl
37、ing valve prior totaking the actual sample.7.2.2 Ensure the displacement the fuel volume in the pipingbetween the sample tap and the storage tank This displacementvolume should be discarded as it may not be representative ofthe fuel to be tested.7.2.2.1 All fluid obtained from a filter sump should b
38、e keptas the sample.7.2.3 Rinse a clean test container thoroughly with the fuelbeing sampled. (WarningFlammable, keep away from heat,sparks, and open flames.)7.2.4 Draw the sample continuously, opening the valvecompletely to obtain a full flush. Do not open or close taps orvalves during sample draw
39、as this action can affect samplequality.7.3 If the test is to be conducted on fuel taken in a separatecontainer for laboratory testing, the container should be shakenvigorously before decanting the fuel into the viewing equip-ment. Sample transfer should be rapid enough to avoid changesin sample tem
40、perature.8. Procedures8.1 Procedure AClear, Transparent Containers:8.1.1 Open Glass or Plastic Container:8.1.1.1 Visual ObservationFill container about three-fourths full. Immediately check for evidence of water orparticulate contamination by holding the sample to the lightand visually examining for
41、 haze or lack of clarity. Close thecontainer and swirl the sample to produce a vortex andexamine the bottom of the vortex for particulate matter andwater droplets. Also look for brown slime or a water layer onthe bottom of the container. Record the particulate and waterappearance rating of the sampl
42、e using the ratings in Tables 1and 2. Record the appearance of any other contaminant usingTable 3 as a guide. Record the ambient temperature.8.1.1.2 Use of Bar Chart and PhotographsImmediatelyon drawing a sample, place the container into a well-lightedarea, avoiding light reflections on the front of
43、 the container asmuch as possible. Place the bar chart directly behind thecontainer, with the lines toward the container and parallel withthe bottom of the container. The narrowest line should be at thebottom of the container. Directly facing the container and barchart, compare the appearance of the
44、 bar chart through thesample with the standard photographs. Place the photographsnext to the container so that they are lighted similarly to thesample. Select the photograph closest in appearance to thesample. Notice that the differences between photographs con-sist both of the successive disappeara
45、nce of lines as well as thegradual lightening of all the lines. Record the number of thethinnest line which is visible through the sample, or record“six” if no lines are visible.8.1.2 Closed Circuit Sampler:8.1.2.1 With fuel flowing under pressure in the main fuelline, open the fill valve wide, fill
46、ing the glass jar to withinabout 25 mm (1 in.) from the top.8.1.2.2 Let the product settle for 1 min or more, if necessary,to remove air bubbles. (CautionThe visual results may differfrom the photographs if the circuit sampler has a diameterdifferent from that of the 100 mm (4 in.) jar used in theph
47、otographs.)8.1.2.3 Examine the glass sampler for hazy/cloudy condi-tions and the bottom for water droplets, solid contaminants,brown slimes, or a combination thereof. Record the particulateand water appearance ratings of the sample using the ratings inTables 1 and 2. Record the appearance of any oth
48、er contami-nant using Table 3 as a guide. If desired, the bar chart andphotos can be used to rate sample clarity as described in8.1.1.2. Record the ambient temperature.NOTE 3While small water droplets and air bubbles may appearsimilar, air bubbles will rise while water droplets will settle upon stan
49、ding.6The “Color and Particle Assessment Rating Guide,” SGTP-3940, is availablefrom Gammon Technical Products, Manasquan, NJ.TABLE 1 Particulate Appearance RatingsRatingRatingGuideDescriptionClear A no particlesA, silt, sediment, dye, rust, orsolids.SlightparticulatesB-C several fine to small size particles.ParticulatematterD many small particles floating or settled onbottomof container.Dirty E-1 discoloration or many particles dispersed infuelor settled on bottom of container.AParticulates determination is sensitive to sampling procedures. See 5.1.1.TABLE 2 Water Cont
