1、Designation: D3427 07D3427 12Designation 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 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 met
3、hod was developed for mineral based oils. It may be 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 as standard. No other units of measurement are included in this standard.1.3 This standard does not
4、purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D
5、1193 Specification for Reagent WaterD1401 Test Method for Water Separability of Petroleum Oils and Synthetic 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
6、 minutes needed for air 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 been heated to a temperature of 25, 50, or 75C. After the air flowis stoppe
7、d, the time required for the air entrained in the oil to reduce in volume to 0.2 % is recorded as the air release time.NOTE 2By agreement between the customer and the laboratory, the oil may be heated at other temperatures. However, the precision at these differenttemperatures is not known at presen
8、t.5. Significance and Use5.1 Agitation of lubricating oil with air in equipment, such as bearings, couplings, gears, pumps, and oil return lines, mayproduce a dispersion of finely divided air bubbles in the oil. If the residence time in the reservoir is too short to allow the air bubbles1 This test
9、method is under the jurisdiction of ASTM Committee D02 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee D02.C0.02on Corrosion and Water/Air Separability.Current edition approved Nov. 1, 2007Dec. 1, 2012. Published December 2007January 2013. Originally approved in
10、 1975. Last previous edition approved in 20062007as D342706. 07. DOI: 10.1520/D3427-12.This standard has been developed through the cooperative effort between ASTM International and the Energy Institute, London. The EI and ASTM International logosimply that the ASTM International and EI standards ar
11、e technically equivalent, but does not imply that both standards are editorially identical. Adopted as a joint ASTM/IPstandard in 2006. DOI: 10.1520/D3427-07.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of AS
12、TM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from Beuth Verlag GmbH, Burggrafenstrasse 6, 1000 Berlin 30, Germany.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what c
13、hanges have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the of
14、ficial document.*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 States1to rise to the oil surface, a mixture of air and oil will circulate through the lubricating oil system. T
15、his may result in an inabilityto maintain oil pressure (particularly with centrifugal pumps), incomplete oil films in bearings and gears, and poor hydraulicsystem performance or failure.5.2 This test method measures the time for the entrained air content to fall to the relatively low value of 0.2 %
16、volume undera standardized set of test conditions and hence permits the comparison of the ability of oils to separate entrained air underconditions where a separation time is available. The significance of this test method has not been fully established. However,entrained air can cause sponginess an
17、d lack of sensitivity of the control of turbine and hydraulic systems. This test may not besuitable for ranking oils in applications where residence times are short and gas contents are high.6. Apparatus6.1 A schematic diagram of the apparatus is shown in Fig. 1. The component parts are described as
18、 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 inletcapillary, baffle plate, and air outlet tube. The two parts of each test vessel should be marked and preferably used as a pair.Interchanged parts may be used so lon
19、g as the resultant test vessel 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:6.1.3.1 Air Thermometer, for measuring compressed air temperature. ASTM Precision Thermometer
20、having a range from 20to 102C, graduated in 0.2C and conforming to the requirements for Thermometer 12C as prescribed in Specification E1 issuitable. A temperature sensor of at least equivalent performance is also suitable. Care shall be taken to avoid restricting the airpath with the thermometer bu
21、lb or any adapter used.6.1.3.2 Sample Thermometer, for measuring the temperature of the sample during preparation and trial runs. ASTM PrecisionThermometer having a range from 20 to 102C, graduated in 0.2C and conforming to the requirements for Thermometer 12Cas prescribed in Specification E1 is sui
22、table. A temperature sensor of at least equivalent performance is also suitable.6.1.4 Heater, to bring the compressed air up to measurement temperature. A coil of copper tubing immersed in the circulatingbath (see 6.1.5) is suitable at 25C, but additional heating is necessary at 50 and 75C. This can
23、 be obtained by an additional bath,or by using a separate steam or electric heat exchanger. The temperature of the air shall be measured by a thermometer locatedas close as possible to the testing vessel and meeting the specifications shown in 6.1.3.NOTE 3The application of thermal insulation to the
24、 pipework carrying the heated compressed air is recommended.6.1.5 Circulating Bath, approximately 10-L capacity with a rate 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 minimize electrosta
25、tic effects.NOTE 5The application of thermal insulation to the pipework carrying the heated bath fluid is recommended.(WarningThe use of glass vessels with glass host fittings for circulating 75C (167F) bath medium is potentially dangerous.Back pressure in excess of a gage pressure of 70 kPa (10 psi
26、) can be generated when the bath medium is pumped at the requiredFIG. 1 Apparatus for the Determination of Air Release TimeD3427 122rate; this can cause fracture of the glass or slippage of the hose connections. Use of a pressure relief valve set at 70 kPa (10 psi)is recommended. In addition, use of
27、 a safety shield is recommended.)6.2 Balance, capable of measuring density, accurate to 0.5 kg/m3.6.3 Sinker, having a round or tapered bottom of 5 or 10-mL displacement, 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 sam
28、ples to 10C above the test temperature.6.5 Timer, readable to 0.1 min, with an accuracy of better than 0.1 %.FIG. 2 Test VesselD3427 1236.6 Pump, with a nonpulsating output and capable of maintaining an air flow of 40 L/min at a pressure of 20 kPa (optional, see7.4).7. Materials7.1 Purity of Reagent
29、sReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that allreagents conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society where suchspecifications are available.4 Other grades may be used, provided it is fi
30、rst ascertained that the reagent is of sufficiently high purityto permit its use without lessening the accuracy of the determination.7.2 Purity of WaterReagent water as defined by Type II of Specification D1193.7.3 Acetone, minimum reagent grade. (WarningFlammable. Health hazard.)7.4 Air, Compressed
31、, dry and free from moisture, particulates, and oil.Air from a cylinder or a nonpulsating pump may be used.(WarningCompressed gas under high pressure.)7.5 Cleaning Reagent, Cleaning either in hot Nochromix5 (WarningCorrosive health hazard oxidizer), or a 24-h soak at roomtemperature in Micro6 soluti
32、on.NOTE 6Previously, chrome sulfuric acid was used in this procedure. Other test methods (for example, Test Method D1401) have demonstratedacceptable, statistically equivalent results when Nochromix or Micro is used to replace sulfuric chromic acid for cleaning.7.6 n-Heptane, reagent grade. (Warning
33、Flammable. Harmful if inhaled.)NOTE 7Other alternate solvents, such as toluene, etc., may be used in place of n-heptane.8. Preparation of Apparatus8.1 Clean the interior of the test vessel, including the air inlet and sinker, and all other glassware coming in contact with thesample, before each dete
34、rmination in the following manner:8.1.1 Rinse away the oil residue with n-heptane (Warningsee 7.6) and acetone (Warningsee 7.3) and dry by air blowing.8.1.2 Clean the apparatus by immersing in cleaning reagent in order to remove completely any traces of silicone.8.1.3 Rinse with reagent water.8.1.4
35、Rinse with acetone (Warningsee 7.3) and dry with clean compressed air (Warningsee 7.4).NOTE 8Oil misting occurs during blowing. The test vessel should be in a hood, or the air outlet tube should be connected to a vent that removes thevapors.9. Procedure9.1 Assemble the test apparatus as shown in Fig
36、. 1. Set the compressed air temperature to within 0.2C of the desired testtemperature. Set the circulating bath to give a specimen temperature within 0.1C of the desired test temperature.The required bathtemperature setting and time for the specimen to equilibrate can be established for an equipment
37、 setup by making trial runs witha thermometer in the oil specimen. For oils with a viscosity at 40C of less than 9.0 cSt, the test temperature shall be 25C. Foroils with a viscosity at 40C between 9.0 and 90 cSt, the test temperature shall be 50C. Oils having a viscosity at 40C greaterthan 90 cSt sh
38、all be tested at 75C.9.2 Warm approximately 200 mL of the oil to be tested in an oven set at a temperature of 10C higher than the test temperature.Allow 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 test vessel.9.4 Allow the sa
39、mple to equilibrate to the desired test temperature, using the heating-up time previously established (see 9.1)or by directly measuring the temperature.9.5 Warm the sinker of the balance to the test temperature in an air bath, such as a glass cylinder fitted with a suitable coversituated in the circ
40、ulating bath. When the sinker has reached the test temperature, immerse it in the sample, taking care that noair bubbles cling to it. Attach the sinker to the beam of the density balance by means of the platinum wire so that the bottom ofthe sinker is 10 6 2 mm from the bottom of the test vessel.4 R
41、eagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For Suggestions on the testing of reagents not listed bythe American Chemical Society, see Annual Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacope
42、ia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.5 The sole source of supply of Nochromix known to the committee at this time is Godax Laboratories, Inc., 720-B Erie Ave., Takoma Park, MD 20912. If you are awareof alternative suppliers, please provide this informat
43、ion toASTM International Headquarters.Your comments will receive careful consideration at a meeting of the responsibletechnical committee,1 which you may attend.6 The sole source of supply of Micro known to the committee at this time is International Products Corp., P.O. Box 70, Burlington, NJ 08016
44、. If you are aware of alternativesuppliers, please provide this information to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the responsible technicalcommittee,1 which you may attend.D3427 124NOTE 9The sinker can take approximately 20 min to reach
45、50C or 35 min to reach 75C.9.6 Allow the density reading to stabilize, read the density from the balance to the nearest 0.1 kg/m3, and record it as the initialdensity.9.7 Return the sinker to the air bath and replace it with the air inlet tube as shown in Fig. 2. After 5 min, start the supply ofair
46、at a gage pressure of 20 kPa at the required temperature. Maintain the pressure and temperature of the air (25, 50, and 75C)by readjustments, if necessary.9.8 After 7 6 0.1 min, shut off the air and immediately start the timer. Quickly remove the inlet tube from the test vessel, andimmerse the sinke
47、r in the oil/air dispersion.Attach the wire to the beam and maintain a distance of 10 6 2 mm between the bottomof the sinker and the bottom of the test vessel.NOTE 10In the case of certain oils, which form a considerable volume of oil/air dispersion, the top of the sinker can initially be in foam, a
48、nd hence,density readings at this time can be in error.9.9 Record the time, to the nearest 0.1 min, for the density to return to the target of 99.8 % of the initial density (d0). If the timeis greater than 30 min, discontinue the test.NOTE 11The test may be run for a longer period of time by agreeme
49、nt between the laboratory and the customer.NOTE 12For some applications, the shape of the air release time curve may be required.This can be implemented by recording the density at intervals,as required.9.10 Certain oils may lose light components during the air saturation, thus changing their effective density. This will be notedif the time for the density to return to the initial figure is instantaneous. Where air release value information is required for suchoils, an air releasing time curve may be drawn. If the loss causes
