1、Designation: D3427 14Designation 31301Standard Test Method forAir Release Properties of Petroleum Oils1This standard is issued under the fixed designation D3427; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revi
2、sion. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the ability of turbine, hydraulic,and gear oils to separate entrained air.NOTE 1This test method was d
3、eveloped for mineral based oils. It maybe used for some synthetic fluids; however, the precision statement appliesonly to petroleum oils.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to a
4、ddress 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 Standards:2D1193 Speci
5、fication for Reagent WaterD1401 Test Method forWater Separability of Petroleum Oilsand Synthetic FluidsD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsE1 Specification for ASTM Liquid-in-Glass Thermometers2.2 DIN Standard:3DIN 51 3813. Terminology3.1 Definitions of Terms Specifi
6、c to This Standard:3.1.1 air release time, nthe number of minutes needed forair entrained in the oil to reduce in volume to 0.2 % under theconditions of this test and at the specified temperature.4. Summary of Test Method4.1 Compressed air is blown through the test oil, which hasbeen heated to a tem
7、perature of (25, 50, 75) C. After the airflow is stopped, the time required for the air entrained in the oilto reduce in volume to 0.2 % is recorded as the air release time.NOTE 2By agreement between the customer and the laboratory, the oilmay be heated at other temperatures. However, the precision
8、at thesedifferent temperatures is not known at present.5. Significance and Use5.1 Agitation of lubricating oil with air in equipment, suchas bearings, couplings, gears, pumps, and oil return lines, mayproduce a dispersion of finely divided air bubbles in the oil. Ifthe residence time in the reservoi
9、r is too short to allow the airbubbles to rise to the oil surface, a mixture of air and oil willcirculate through the lubricating oil system. This may result inan inability to maintain oil pressure (particularly with centrifu-gal pumps), incomplete oil films in bearings and gears, andpoor hydraulic
10、system performance or failure.5.2 This test method measures the time for the entrained aircontent to fall to the relatively low value of 0.2 % volumeunder a standardized set of test conditions and hence permitsthe comparison of the ability of oils to separate entrained airunder conditions where a se
11、paration time is available. Thesignificance of this test method has not been fully established.However, entrained air can cause sponginess and lack ofsensitivity of the control of turbine and hydraulic systems. Thistest may not be suitable for ranking oils in applications whereresidence times are sh
12、ort and gas contents are high.6. Apparatus6.1 Aschematic diagram of the apparatus is shown in Fig. 1.The component parts are described as follows:6.1.1 Test Vessel, made of borosilicate glass as shown in Fig.2, consisting of a jacketed sample tube fitted with an air inlet1This test method is under t
13、he jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.C0.02 on Corrosion and Water/Air Separability.Current edition approved May 1, 2014. Published June 2014. Originallyapproved in 1975. Last previous edition appr
14、oved in 2012 as D3427 12. DOI:10.1520/D3427-14.This standard has been developed through the cooperative effort betweenASTMInternational and the Energy Institute, London. The EI and ASTM Internationallogos imply that the ASTM International and EI standards are technicallyequivalent, but does not impl
15、y that both standards are editorially identical. Adoptedas a joint ASTM/IP standard in 2006.2For 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 S
16、ummary page onthe ASTM website.3Available from Beuth Verlag GmbH, Burggrafenstrasse 6, 1000 Berlin 30,Germany.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1capillary,
17、baffle plate, and air outlet tube. The two parts of eachtest vessel should be marked and preferably used as a pair.Interchanged parts may be used so long as the resultant testvessel conforms to the stated dimensions.6.1.2 Pressure Gage, covering the range from 0 kPa to35 kPa, with divisions at least
18、 every 2 kPa, and an accuracy of1.5 kPa.6.1.3 Thermometers:6.1.3.1 Air Thermometer, for measuring compressed airtemperature. ASTM Precision Thermometer having a rangefrom 20 C to 102 C, graduated in 0.2 C and conforming tothe requirements for Thermometer 12C as prescribed in Speci-fication E1 is sui
19、table. A temperature sensor of at leastequivalent performance is also suitable. Care shall be taken toavoid restricting the air path with the thermometer bulb or anyadapter used.6.1.3.2 Sample Thermometer, for measuring the temperatureof the sample during preparation and trial runs. ASTM Preci-sion
20、Thermometer having a range from 20 C to 102 C,graduated in 0.2 C and conforming to the requirements forThermometer 12C as prescribed in Specification E1 is suitable.Atemperature sensor of at least equivalent performance is alsosuitable.6.1.4 Heater, to bring the compressed air up to measurementtempe
21、rature. A coil of copper tubing immersed in the circulat-ing bath (see 6.1.5) is suitable at 25 C, but additional heatingis necessary at 50 C and 75 C. This can be obtained by anadditional bath, or by using a separate steam or electric heatexchanger. The temperature of the air shall be measured by a
22、thermometer located as close as possible to the testing vesseland meeting the specifications shown in 6.1.3.NOTE 3The application of thermal insulation to the pipework carryingthe heated compressed air is recommended.6.1.5 Circulating Bath, approximately 10 L capacity with arate of flow of 10 L/min
23、and capable of maintaining the test cellat a temperature of (25, 50, 75) C within 60.1 C.NOTE 4Use of water in the bath has been found to minimizeelectrostatic effects.NOTE 5The application of thermal insulation to the pipework carryingthe heated bath fluid is recommended.(WarningThe use of glass ve
24、ssels with glass hose fittingsfor circulating 75 C bath medium is potentially dangerous.Back pressure in excess of a gage pressure of 70 kPa can begenerated when the bath medium is pumped at the requiredrate; this can cause fracture of the glass or slippage of the hoseconnections. Use of a pressure
25、relief valve set at 70 kPa isrecommended. In addition, use of a safety shield is recom-mended.)6.2 Balance, capable of measuring density, accurate to0.5 kg/m3.6.3 Sinker, having a round or tapered bottom of 5 mL or10 mL displacement, 80.0 mm 6 1.5 mm length. If the sinkercontains a thermometer, it s
26、hall be usable between 25 C and75 C.6.4 Oven, capable of heating samples to 10 C above the testtemperature.6.5 Timer, readable to 1 s, with an accuracy of better than0.1 %.6.6 Pump, with a nonpulsating output and capable ofmaintaining an air flow of 40 L/min at a pressure of 20 kPa(optional, see 7.4
27、).7. 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 wheresuch specifications are available.4Other grade
28、s 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 Purity of WaterReagent water as defined by Type II ofSpecification D1193.7.3 Acetone, minimum reagent grade. (WarningFlammable. Healt
29、h hazard.)7.4 Air, Compressed, dry and free from moisture,particulates, and oil. Air from a cylinder or a nonpulsatingpump may be used. (WarningCompressed gas under highpressure.)4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions o
30、n 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.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.FIG. 1 Apparatus for the Determination
31、 of Air Release TimeD3427 142FIG. 2 Test VesselD3427 1437.5 Cleaning Reagent, Cleaning either in hot Nochromix5(WarningCorrosive health hazard oxidizer), or a 24 h soakat room temperature in Micro6solution.NOTE 6Previously, chrome sulfuric acid was used in this procedure.Other test methods (for exam
32、ple, Test Method D1401) have demonstratedacceptable, statistically equivalent results when Nochromix or Micro isused to replace sulfuric chromic acid for cleaning.7.6 n-Heptane, reagent grade. (WarningFlammable.Harmful if inhaled.)NOTE 7Other alternate solvents, such as toluene, etc., may be used in
33、place of n-heptane.8. Sampling8.1 Sample in accordance with the instructions described inPractice D4057.9. Preparation of Apparatus9.1 Clean the interior of the test vessel, including the airinlet and sinker, and all other glassware coming in contact withthe sample, before each determination in the
34、following manner:9.1.1 Rinse away the oil residue with n-heptane(Warningsee 7.6) and acetone (Warningsee 7.3) and dryby air blowing.9.1.2 Clean the apparatus by immersing in cleaning reagentin order to remove completely any traces of silicone.9.1.3 Rinse with reagent water.9.1.4 Rinse with acetone (
35、Warningsee 7.3) and dry withclean compressed air (Warningsee 7.4).NOTE 8Oil misting occurs during blowing. The test vessel should bein a hood, or the air outlet tube should be connected to a vent that removesthe vapors.10. Procedure10.1 Assemble the test apparatus as shown in Fig. 1. Set thecompress
36、ed air temperature to within 0.2 C of the desired testtemperature. Set the circulating bath to give a specimentemperature within 0.1 C of the desired test temperature. Therequired bath temperature setting and time for the specimen toequilibrate can be established for an equipment setup bymaking tria
37、l runs with a thermometer in the oil specimen. Foroils with a viscosity at 40 C of less than 9.0 mm2/s, the testtemperature shall be 25 C. For oils with a viscosity at 40 Cbetween 9.0 mm2/s and 90 mm2/s, the test temperature shall be50 C. Oils having a viscosity at 40 C greater than 90 mm2/sshall be
38、 tested at 75 C.10.2 Warm approximately 200 mL of the oil to be tested inan oven set at a temperature of 10 C higher than the testtemperature. Allow the sample to reach the test temperature.This may take about 20 min.10.3 Pour 180 mL 6 5 mLof the heated sample into the testvessel.10.4 Allow the samp
39、le to equilibrate to the desired testtemperature, using the heating-up time previously established(see 10.1) or by directly measuring the temperature.10.5 Warm the sinker of the balance to the test temperaturein an air bath, such as a glass cylinder fitted with a suitablecover situated in the circul
40、ating bath. When the sinker hasreached the test temperature, immerse it in the sample, takingcare that no air bubbles cling to it. Attach the sinker to thebeam of the density balance by means of the platinum wire sothat the bottom of the sinker is 10 mm 6 2 mm from thebottom of the test vessel.NOTE
41、9The sinker can take approximately 20 min to reach 50 C or35 min to reach 75 C.10.6 Allow the density reading to stabilize, read the densityfrom the balance to the nearest 0.1 kg/m3, and record it as theinitial density.10.7 Return the sinker to the air bath and replace it with theair inlet tube as s
42、hown in Fig. 2. After 5 min, start the supplyof air at a gage pressure of 20 kPa at the required temperature.Maintain the pressure and temperature of the air (25, 50, 75) Cby readjustments, if necessary.10.8 After 7 min 6 0.1 min, shut off the air and immediatelystart the timer. Quickly remove the i
43、nlet tube from the testvessel, and immerse the sinker in the oil/air dispersion. Attachthe wire to the beam and maintain a distance of 10 mm 62 mm between the bottom of the sinker and the bottom of thetest vessel.NOTE 10In the case of certain oils, which form a considerable volumeof oil/air dispersi
44、on, the top of the sinker can initially be in foam, andhence, density readings at this time can be in error.10.9 Record the time, to the nearest 1 s, for the density toreturn to the target of 99.8 % of the initial density (d0). If thetime is greater than 30 min, discontinue the test.NOTE 11The test
45、may be run for a longer period of time by agreementbetween the laboratory and the customer.NOTE 12For some applications, the shape of the air release time curvemay be required. This can be implemented by recording the density atintervals, as required.10.10 Certain oils may lose light components duri
46、ng the airsaturation, thus changing their effective density. This will benoted if the time for the density to return to the initial figure isinstantaneous. Where air release value information is requiredfor such oils, an air releasing time curve may be drawn. If theloss causes any part of the sinker
47、 to be exposed, discontinue thetest and repeat, using a sample that is 10 mL larger thanpreviously used.11. Calculation of Density11.1 Density:Mass of sinker in air kg! 2 Mass of sinker in sample kg!#Volume of sinker m3!(1)Density of sample kg/m3!55The sole source of supply of Nochromix known to the
48、 committee at this timeis Godax Laboratories, Inc., 720-B Erie Ave., Takoma Park, MD 20912. If you areaware of alternative suppliers, please provide this information to ASTM Interna-tional Headquarters. Your comments will receive careful consideration at a meetingof the responsible technical committ
49、ee,1which you may attend.6The sole source of supply of Micro known to the committee at this time isInternational Products Corp., P.O. Box 70, Burlington, NJ 08016. If you are awareof alternative suppliers, please provide this information to ASTM InternationalHeadquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee,1which you may attend.D3427 144NOTE 13A 10 mL sinker has a volume of 10 m310-6m3.11.2 Target Density:Initial density d0! 30.998. (2)11.3 If the tare
