1、Designation: D 3427 07Designation 31301An American National StandardStandard Test Method forAir Release Properties of Petroleum Oils1This standard is issued under the fixed designation D 3427; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、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.1. Scope*1.1 This test method covers the ability of turbine, hydraulic,and gear oils to separate entrained a
3、ir.NOTE 1This test method was developed for mineral based oils. It maybe used for some synthetic fluids; however, the precision statement appliesonly to petroleum oils.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of
4、 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:2D 1193 Specification for Reagent WaterD 1401 Test Method for Water Separability of PetroleumOils and Syn
5、thetic FluidsE1 Specification for ASTM Liquid-in-Glass Thermometers2.2 DIN Standard:3DIN 51 3813. Terminology3.1 Definitions 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 t
6、est and at the specified temperature.4. Summary of Test Method4.1 Compressed air is blown through the test oil, which hasbeen heated to a temperature of 25, 50, or 75C. 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
7、 release time.NOTE 2By agreement between the customer and the laboratory, theoil may be heated at other temperatures. 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, coupling
8、s, gears, pumps, and oil return lines, mayproduce a dispersion of finely divided air bubbles in the oil. Ifthe residence 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 i
9、nan inability to maintain oil pressure (particularly with centrifu-gal pumps), incomplete oil films in bearings and gears, 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 st
10、andardized set of test conditions and hence permitsthe comparison of the ability of oils to separate entrained airunder 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 ofsensitivi
11、ty of the control of turbine and hydraulic systems. Thistest may not be suitable for ranking oils in applications whereresidence 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 Ve
12、ssel, made of borosilicate glass as shown in Fig.2, consisting of a jacketed sample tube fitted with an air inletcapillary, 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 testv
13、essel conforms to the stated dimensions.6.1.2 Pressure Gage, covering the range from 0 to 35 kPa,with divisions at least every 2 kPa, and an accuracy of 1.5 kPa.6.1.3 Thermometers:1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct
14、responsibility of SubcommitteeD02.C0.02 on Corrosion and Water/Air Separability.Current edition approved Nov. 1, 2007. Published December 2007. Originallyapproved in 1975. Last previous edition approved in 2006 as D 342706.Adopted as a joint ASTM/IP standard in 2006.2For referenced ASTM standards, v
15、isit 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.3Available from Beuth Verlag GmbH, Burggrafenstrasse 6, 1000 Berlin 30,Germany.1*A Summary of
16、Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.1.3.1 Air Thermometer, for measuring compressed airtemperature. ASTM Precision Thermometer having a rangefrom 20 to 102C, graduated
17、in 0.2C and conforming to therequirements for Thermometer 12C as prescribed in Specifi-cation E1is suitable. A temperature sensor of at least equiva-lent performance is also suitable. Care shall be taken to avoidrestricting the air path with the thermometer bulb or anyadapter used.6.1.3.2 Sample The
18、rmometer, for measuring the tempera-ture of the sample during preparation and trial runs. ASTMPrecision Thermometer having a range from 20 to 102C,graduated in 0.2C and conforming to the requirements forThermometer 12C as prescribed in Specification E1is suit-able.Atemperature sensor of at least equ
19、ivalent performance isalso suitable.6.1.4 Heater, to bring the compressed air up to measure-ment temperature. A coil of copper tubing immersed in thecirculating bath (see 6.1.5) is suitable at 25C, but additionalheating is necessary at 50 and 75C.This can be obtained by anadditional bath, or by usin
20、g a separate steam or electric heatexchanger. The temperature of the air shall be measured by athermometer 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 carry-ing the heated compressed air i
21、s recommended.6.1.5 Circulating Bath, approximately 10-L capacity with arate of flow of 10 L/min and capable of maintaining the test cellat a temperature of 25, 50, or 75C within 60.1C.NOTE 4Use of water in the bath has been found to minimizeelectrostatic effects.NOTE 5The application of thermal ins
22、ulation to the pipework carry-ing the heated bath fluid is recommended.(WarningThe use of glass vessels with glass host fittingsfor circulating 75C (167F) bath medium is potentiallydangerous. Back pressure in excess of a gage pressure of 70kPa (10 psi) can be generated when the bath medium ispumped
23、at the required rate; this can cause fracture of the glassor slippage of the hose connections. Use of a pressure reliefvalve set at 70 kPa (10 psi) is recommended. In addition, useof a safety shield is recommended.)6.2 Balance, capable of measuring density, accurate to 0.5kg/m3.6.3 Sinker, having a
24、round or tapered bottom of 5 or 10-mLdisplacement, 80.0 6 1.5-mm length. If the sinker contains athermometer, it shall be usable between 25 and 75C.6.4 Oven, capable of heating samples to 10C above the testtemperature.6.5 Timer, readable to 0.1 min, with an accuracy of betterthan 0.1 %.6.6 Pump, wit
25、h a nonpulsating output and capable ofmaintaining an air flow of 40 L/min at a pressure 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 C
26、ommittee onAnalytical Reagents of the American Chemical Society wheresuch specifications 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 WaterRea
27、gent water as defined by Type II ofSpecification D 1193.7.3 Acetone, minimum reagent grade. (WarningFlammable. Health hazard.)7.4 Air, Compressed, dry and free from moisture, particu-lates, and oil. Air from a cylinder or a nonpulsating pump maybe used. (WarningCompressed gas under high pressure.)7.
28、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 example, Test Method D 1401) have demonstratedacceptable, stat
29、istically equivalent results when Nochromix or Micro isused to replace sulfuric chromic acid for cleaning.7.6 n-Heptane, reagent grade. (WarningFlammable.Harmful if inhaled.)4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the
30、 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.5The sole source of supply of Nochromix kno
31、wn to the 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 technica
32、l 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
33、 receive careful consideration at a meeting of theresponsible technical committee,1which you may attend.FIG. 1 Apparatus for the Determination of Air Release TimeD3427072NOTE 7Other alternate solvents, such as toluene, etc., may be used inplace of n-heptane.8. Preparation of Apparatus8.1 Clean the i
34、nterior of the test vessel, including the airinlet and sinker, and all other glassware coming in contact withthe sample, before each determination in the following manner:8.1.1 Rinse away the oil residue with n-heptane(Warningsee 7.6) and acetone (Warningsee 7.3) and dryby air blowing.8.1.2 Clean th
35、e apparatus by immersing in cleaning reagentin order to remove completely any traces of silicone.8.1.3 Rinse with reagent water.FIG. 2 Test VesselD34270738.1.4 Rinse with acetone (Warningsee 7.3) and dry withclean compressed air (Warningsee 7.4).NOTE 8Oil misting occurs during blowing. The test vess
36、el should bein a hood, or the air outlet tube should be connected to a vent that removesthe vapors.9. Procedure9.1 Assemble the test apparatus as shown in Fig. 1. Set thecompressed air temperature to within 0.2C of the desired testtemperature. Set the circulating bath to give a specimentemperature w
37、ithin 0.1C of the desired test temperature. Therequired bath temperature setting and time for the specimen toequilibrate can be established for an equipment setup bymaking trial runs with a thermometer in the oil specimen. Foroils with a viscosity at 40C of less than 9.0 cSt, the testtemperature sha
38、ll be 25C. For oils with a viscosity at 40Cbetween 9.0 and 90 cSt, the test temperature shall be 50C. Oilshaving a viscosity at 40C greater than 90 cSt shall be tested at75C.9.2 Warm approximately 200 mLof the oil to be tested in anoven set at a temperature of 10C higher than the testtemperature. Al
39、low the sample to reach the test temperature.This may take about 20 min.9.3 Pour 180 6 5 mL of the heated sample into the testvessel.9.4 Allow the sample to equilibrate to the desired testtemperature, using the heating-up time previously established(see 9.1) or by directly measuring the temperature.
40、9.5 Warm the sinker of the balance to the test temperature inan air bath, such as a glass cylinder fitted with a suitable coversituated in the circulating bath. When the sinker has reachedthe test temperature, immerse it in the sample, taking care thatno air bubbles cling to it. Attach the sinker to
41、 the beam of thedensity balance by means of the platinum wire so that thebottom of the sinker is 10 6 2 mm from the bottom of the testvessel.NOTE 9The sinker can take approximately 20 min to reach 50C or 35min to reach 75C.9.6 Allow the density reading to stabilize, read the densityfrom the balance
42、to the nearest 0.1 kg/m3, and record it as theinitial density.9.7 Return the sinker to the air bath and replace 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
43、(25, 50, and75C) by readjustments, if necessary.9.8 After 7 6 0.1 min, shut off the air and immediately startthe timer. Quickly remove the inlet tube from the test vessel,and immerse the sinker in the oil/air dispersion.Attach the wireto the beam and maintain a distance of 10 6 2 mm between thebotto
44、m of the sinker and the bottom of the test vessel.NOTE 10In the case of certain oils, which form a considerable volumeof oil/air dispersion, the top of the sinker can initially be in foam, andhence, density readings at this time can be in error.9.9 Record the time, to the nearest 0.1 min, for the de
45、nsityto return to the target of 99.8 % of the initial density (d0). If thetime is greater than 30 min, discontinue the test.NOTE 11The test 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 curve
46、may be required. This can be implemented by recording the density atintervals, as required.9.10 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
47、 air release value information is requiredfor such oils, an air releasing time curve may be 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.10. Calculation of Density10.1 Density:Density of sample
48、kg/m3!5 (1)Weight of sinker in air kg! Weight of sinker in sample kg!#Volume of sinker m3!NOTE 13A 10 mL sinker has a volume of 10 3 10-6m3.10.2 Target Density:Initial density d0!30.998. (2)10.3 If the tare key of the balance is pressed while the sinkeris being weighed in air so that the reading is
49、zeroed, then thefollowing may be used:Density of sample kg/m3!5Weight of sinker in sample kg!Volume of sinker m3!(3)NOTE 14Some instruments automatically make the above calcula-tions.10.4 The volume of the sinker may be determined byweighing it in air, then in water. The difference in weight (kg)3 103= volume in m3.11. Reporting11.1 Report the air release time, as recorded in 9.9, and thetest temperature in C.12. Precision and Bias7NOTE 15The program was run by six laboratories, using five samplesof unused steam turb
