1、Designation: D3427 15Designation 31301Standard Test Method forAir Release Properties of Hydrocarbon Based 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 l
2、ast revision. 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 meth
3、od was developed for hydrocarbon based oils.It may be used for some synthetic fluids; however, the precision statementapplies only to hydrocarbon based 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 d
4、oes 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 St
5、andards:2D1193 Specification 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 Definiti
6、ons of Terms Specific 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 has
7、been heated to a temperature of 25 C, 50 C, or 75 C. Afterthe air flow is stopped, the time required for the air entrainedin the oil to reduce in volume to 0.2 % is recorded as the airrelease time.NOTE 2By agreement between the customer and the laboratory, the oilmay be heated at other temperatures.
8、 However, the precision 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 reside
9、nce time in the reservoir 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 g
10、ears, andpoor hydraulic 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 airund
11、er conditions where a separation 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 whe
12、reresidence times are short 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 inlet1Thi
13、s test method is under the 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 Oct. 1, 2015. Published November 2015. Originallyapproved in 197
14、5. Last previous edition approved in 2014 as D3427 14a1. DOI:10.1520/D3427-15.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 technical
15、lyequivalent, but does not imply 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, re
16、fer to the standards Document Summary 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-
17、2959. United States1capillary, 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.NOTE 3Users are advised to verify the distance betwee
18、n the air inletcapillary and the bottom of the test cell as described in the method, byusing an appropriate measuring device. It has been noted by somelaboratories that variation from the required measurements has significanteffect on results.6.1.2 Pressure Gage, covering the range from 0 kPa to35 k
19、Pa, with divisions at least 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
20、in Speci-fication E1 is suitable. 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 t
21、rial runs. ASTM Preci-sion 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
22、 air up to measurementtemperature. 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
23、 air shall be measured by athermometer located as close as possible to the testing vesseland meeting the specifications shown in 6.1.3.NOTE 4The application of thermal insulation to the pipework carryingthe heated compressed air is recommended.6.1.5 Circulating Bath, approximately 10 L capacity with
24、 arate of flow of 10 L/min and capable of maintaining the test cellat a temperature of 25 C, 50 C, or 75 C within 60.1 C.NOTE 5Use of water in the bath has been found to minimizeelectrostatic effects.NOTE 6The application of thermal insulation to the pipework carryingthe heated bath fluid is recomme
25、nded.(WarningThe use of glass vessels 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 hos
26、econnections. Use of a pressure 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 kgm3.6.3 Sinker, having a round or tapered bottom of 5 mL or10 mL displacement, 80.0 mm 6 1.5 mm length. If the sin
27、kercontains a thermometer, it shall 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 press
28、ure of 20 kPa(optional, see 7.4).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 specificat
29、ions are available.4Other 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 Purity of WaterReagent water as defined by Type II ofSpecification D1193.7.3 Acetone, minimum reagent
30、grade. (WarningFlammable. Health hazard.)4Reagent Chemicals, American 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, Dorse
31、t, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.FIG. 1 Apparatus for the Determination of Air Release TimeD3427 152FIG. 2 Test VesselD3427 1537.4 Air, Compressed, dry and free from moisture,particulates, and oil. Air from a
32、cylinder or a nonpulsatingpump may be used. (WarningCompressed gas under highpressure.)7.5 Cleaning Reagent, Cleaning either in hot Nochromix5(WarningCorrosive health hazard oxidizer), or a 24 h soakat room temperature in Micro6solution.NOTE 7Previously, chrome sulfuric acid was used in this procedu
33、re.Other test methods (for example, 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 8Other alternate solvents, such a
34、s toluene, etc., may be used inplace 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, be
35、fore each determination in the 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 w
36、ater.9.1.4 Rinse with acetone (Warningsee 7.3) and dry withclean compressed air (Warningsee 7.4).NOTE 9Oil 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 s
37、hown in Fig. 1. Set thecompressed 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 a
38、n equipment setup bymaking trial 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
39、C greater than 90 mm2/sshall be 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
40、 testvessel.10.4 Allow the sample 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 suita
41、blecover situated in the circulating 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 the
42、bottom of the test vessel.NOTE 10The 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 replac
43、e it with theair inlet tube as shown 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 C, 50 C,or 75 C by readjustments, if necessary.10.8 After 7 min 6 0.1 min, shut off the air and immediately
44、start the timer. Quickly remove the inlet 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 11In the case of certain oils, which form a c
45、onsiderable volumeof oil/air dispersion, 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 0.1 min (6 s), for thedensity to return to the target of 99.8 % of the initial density(d0). If the time is greater tha
46、n 30 min, discontinue the test.NOTE 12The test may be run for a longer period of time by agreementbetween the laboratory and the customer.NOTE 13For some applications, the shape of the air release time curvemay be required. This can be implemented by recording the density atintervals, as required.10
47、.10 Certain oils may lose light components during 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
48、drawn. If theloss causes any part of the sinker to be exposed, discontinue thetest and repeat, using a sample that is 10 mL larger thanpreviously used.5The sole source of supply of Nochromix known to the committee at this timeis Godax Laboratories, Inc., 720-B Erie Ave., Takoma Park, MD 20912. If yo
49、u 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 committee,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 consideratio
