ASTM D2878-1995(2005) Standard Test Method for Estimating Apparent Vapor Pressures and Molecular Weights of Lubricating Oils《润滑油表面蒸气压力和分子量评估的标准试验方法》.pdf
《ASTM D2878-1995(2005) Standard Test Method for Estimating Apparent Vapor Pressures and Molecular Weights of Lubricating Oils《润滑油表面蒸气压力和分子量评估的标准试验方法》.pdf》由会员分享,可在线阅读,更多相关《ASTM D2878-1995(2005) Standard Test Method for Estimating Apparent Vapor Pressures and Molecular Weights of Lubricating Oils《润滑油表面蒸气压力和分子量评估的标准试验方法》.pdf(6页珍藏版)》请在麦多课文档分享上搜索。
1、Designation: D 2878 95 (Reapproved 2005)An American National StandardStandard Test Method forEstimating Apparent Vapor Pressures and MolecularWeights of Lubricating Oils1This standard is issued under the fixed designation D 2878; the number immediately following the designation indicates the year of
2、original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method provides a calculation procedure forconve
3、rting data obtained by Test Method D 972 to apparentvapor pressures and molecular weights. It has been demon-strated to be applicable to petroleum-based and synthetic esterlubricating oils,2at temperatures of 395 to 535K (250 to500F). However, its applicability to lubricating greases hasnot been est
4、ablished.NOTE 1Most lubricants boil over a fairly wide temperature range, afact recognized in discussion of their vapor pressures. For example, theapparent vapor pressure over the range 0 to 0.1 % evaporated may be asmuch as 100 times that over the range 4.9 to 5.0 % evaporated.1.2 The values stated
5、 in SI units are to be regarded as thestandard. In cases in which materials, products, or equipmentare available in inch-pound units only, SI units are omitted.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the use
6、r of this standard to establish appro-priate safety and health practices and determine the applica-bility or regulatory limitations prior to use. For specificwarning statements, see 6.2, 7.1, 8.2, and Annex A2.2. Referenced Documents2.1 ASTM Standards:3A 240/A 240M Specification for Heat-Resisting C
7、hromiumand Chromium-Nickel Stainless Steel Plate, Sheet, andStrip for Pressure VesselsD92 Test Method for Flash and Fire Points by ClevelandOpen CupD 972 Test Method for Evaporation Loss of LubricatingGreases and OilsD 2503 Test Method for Molecular Weight (Relative Mo-lecular Mass) of Hydrocarbons
8、by Thermoelectric Mea-surement of Vapor PressureD 2595 Test Method for Evaporation Loss of LubricatingGreases over Wide Temperature RangeD 2883 Test Method for Reaction Threshold Temperature ofLiquid and Solid MaterialsE1 Specification for ASTM ThermometersE 659 Test Method for Autoignition Temperat
9、ure of LiquidChemicals3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 apparent vapor pressure (p), nthe time-averagedvalue of the vapor pressure from the start to the end of theevaporation test.3.1.1.1 DiscussionWhile this may include some effects ofdifferences in nonideality
10、of the vapor, heat of vaporization,surface tension, and viscosity between the m-terphenyl and thelubricating oil, these factors have been demonstrated to benegligible. Unless stated, this average shall cover the range 0 to5 6 1%.3.1.2 cell constant (k), nthe ratio of the amount ofm-terphenyl or lubr
11、icating oil carried off per unit volume of gasto that predicted by Daltons law.k 5 22.41 PW /VpM (1)where:k = call constantP = ambient atmospheric pressure, torrW = mass of lubricant evaporated, gV = volume of gas passed through all litres at 273K and101.3 kPa (760 torr)p = apparent vapor pressure,
12、torrM = mole average molecular weight of lubricant vapor,g/moleT = test temperature, KIt has been empirically determined that for m-terphenyl in airk 5 0.1266 2 12.60/ T 2 273! (2)1This test method is under the jurisdiction of Committee D02 on PetroleumProducts and Lubricants and is the direct respo
13、nsibility of Subcommittee D02.11 onEngineering Sciences of High Performance Fluids and Solids.Current edition approved June 1, 2005. Published September 2005. Originallyapproved in 1970. Last previous edition approved in 2000 as D 287895(2000)e1.2Coburn, J. F., “Lubricant Vapor Pressure Derived from
14、 Evaporation Loss,”Transactions,American Society of Lubricating Engineers,ASLTA,Vol 12, 1969, pp.129134.3For 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 standard
15、s Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.and that the cell constant is independent of the compositionof the lubricant.3.1.3 Test Method D 972 is normally run with air, whichmay cause
16、changes in easily oxidized fluids. In such cases, useof common reactive gas nitrogen and recalibration to obtain aslightly different cell constant (k8) is mandatory.4. Summary of Test Method4.1 The test is run at the selected temperature for a sufficienttime to give the selected amount of evaporatio
17、n, which is 5 61 % unless otherwise specified. This evaporation rate is com-pared with a standard value for pure m-terphenyl to yield theapparent vapor pressure and molecular weight of the lubricat-ing oil as defined in Section 3.5. Significance and Use5.1 The vapor pressure of a substance as determ
18、ined bymeasurement of evaporation reflects a property of the bulksample. Little weight is given by the procedure to the presenceof low concentrations of volatile impurities.5.2 Vapor pressure, per se, is a thermodynamic property thatis dependent only upon composition and temperature for stablesystem
19、s. In the present method, composition changes occurduring the course of the test so that the contribution of minoramounts of volatile impurities is minimized.6. Apparatus6.1 Evaporation Cell, as described in Annex A1.6.2 Air Supply System, capable of supplying to the cell therequired flow of air fre
20、e of entrained particles (WarningCompressed gas under high pressure. Use with extreme cautionin the presence of combustible material, since the autoignitiontemperatures of most organic compounds in air are drasticallyreduced at elevated pressures. See Annex A2.1.). A 410-mm(16-in.) length of 1-in. d
21、iameter pipe packed with glass woolhas been found satisfactory for filtering the air.6.3 Oil Bath, as described in Annex A1.NOTE 2Other constant-temperature baths may be used if the exit airpassing over the grease sample is at the test temperature (60.5K (1F).6.4 ThermometersASTM thermometers gradua
22、ted in ei-ther Celsius or Fahrenheit degrees and having a range from 5to 400C (20 to 760F) and conforming to the requirements forThermometers 3C or 3F, respectively, as described in Specifi-cation E1.6.5 Flowmeter4A rotameter calibrated to deliver air at arate of 2.583 6 0.02 g/min between 289 and 3
23、02K (60 and85F) (2 L/min at standard temperature and pressure). It shallbe furnished with a needle valve and mounted as shown in Fig.1.6.6 Oil Sample Cup, as described in Fig. 1 and A1.1.2.7. Calibration of Equipment7.1 It is assumed that equipment conforming to Test MethodD 972 in design and instal
24、lation needs no calibration. Ifquestions arise, carry out the procedure using m-terphenyl(WarningHarmful or fatal if swallowed. See A2.2.) of goodcommercial quality.5The following two points shall be deter-mined:Temperature Evaporation to Conformto Eq 2, gK F Time, h395 250 22 0.267 6 0.027420 300 6
- 1.请仔细阅读文档,确保文档完整性,对于不预览、不比对内容而直接下载带来的问题本站不予受理。
- 2.下载的文档,不会出现我们的网址水印。
- 3、该文档所得收入(下载+内容+预览)归上传者、原创作者;如果您是本文档原作者,请点此认领!既往收益都归您。
下载文档到电脑,查找使用更方便
10000 积分 0人已下载
下载 | 加入VIP,交流精品资源 |
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- ASTMD287819952005STANDARDTESTMETHODFORESTIMATINGAPPARENTVAPORPRESSURESANDMOLECULARWEIGHTSOFLUBRICATINGOILS

链接地址:http://www.mydoc123.com/p-513700.html