1、Designation: D 4871 06An American National StandardStandard Guide forUniversal Oxidation/Thermal Stability Test Apparatus1This standard is issued under the fixed designation D 4871; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, t
2、he 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. Scope*1.1 This guide covers an apparatus used to measure theoxidation or thermal stability of liquids by subjecting
3、 them totemperatures in the range from 50 to 375C in the presence ofair, oxygen, nitrogen, or other gases at flow rates of 1.5 to13 L/h, or in the absence of gas flow. Stability may bemeasured in the presence or absence of water or soluble orinsoluble catalysts. Gases evolved may be allowed to escap
4、e,condensed and collected, or condensed and returned to the testcell.1.2 This standard does 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
5、applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D91 Test Method for Precipitation Number of LubricatingOilsD 156 Test Method for Saybolt Color of Petroleum Prod-ucts (Saybolt Chromometer Method)D 445 Test Method for Kinematic Viscosity of Transparenta
6、nd Opaque Liquids (and the Calculation of DynamicViscosity)D 664 Test Method forAcid Number of Petroleum Productsby Potentiometric TitrationD 974 Test Method for Acid and Base Number by Color-Indicator TitrationD 1500 Test Method for ASTM Color of Petroleum Prod-ucts (ASTM Color Scale)D 3339 Test Me
7、thod for Acid Number of Petroleum Prod-ucts by Semi-Micro Color Indicator TitrationD 5763 Test Method for Oxidation and Thermal StabilityCharacteristics of Gear Oils Using Universal GlasswareD 5770 Test Method for Semiquantitative Micro Determi-nation of Acid Number of Lubricating Oils During Oxida-
8、tion TestingD 5846 Test Method for Universal Oxidation Test for Hy-draulic and Turbine Oils Using the Universal OxidationTest ApparatusD 6514 Test Method for High Temperature Universal Oxi-dation Test for Turbine Oils3. Summary of Guide3.1 An apparatus is described in which a sample of testfluid, ty
9、pically from 100 ml or 100 g, is subjected to thermal oroxidative degradation or both. Insoluble or soluble catalystmay be added. Gas may be bubbled through the liquid toprovide agitation or to promote oxidation or both. Water orwater vapor may be added. At the end of the test or at intervalsthrough
10、out the test, the liquid is monitored for change inneutralization number, viscosity, weight loss, formation ofsludge, or for other parameters. The corrosivity of the fluidtoward any catalyst metals can be determined from theappearance and weight change of the metal test specimens, ifpresent, or by m
11、onitoring the oil and any sludge or water formetal content. The test is terminated after a fixed time periodor when a selected parameter reaches a condemning value.NOTE 1The volume of liquid at test temperature should be sufficientto cover the catalysts and should not extend beyond the heated portio
12、n ofthe bath.4. Significance and Use4.1 This standard describes an apparatus that provides theversatility required to conduct oxidation or thermal stabilitytests on liquids using a wide variety of test conditions. It is1This guide is under the jurisdiction of ASTM Committee D02 on PetroleumProducts
13、and Lubricants and is the direct responsibility of Subcommittee D02.09 onOxidation.Current edition approved May 1, 2006. Published May 2006. Originallyapproved in 1988. Last previous edition approved in 2000 as D 487100.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact
14、ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Con
15、shohocken, PA 19428-2959, United States.sufficiently flexible so that new test conditions can be chosen inresponse to the changing demands of the marketplace.4.2 Procedures using this apparatus are described in thefollowing ASTM standard test methods: D 5763, D 5846, andD 6514. Other procedures may
16、be in use, but they have notbeen developed as ASTM standard test methods.5. Apparatus5.1 Heating Block, as shown at the lower right in Fig. 1,toprovide a controlled constant temperature for conducting tests.5.1.1 Test cells are maintained at constant elevated tempera-ture by means of a heated alumin
17、um block which surroundseach test cell.5.1.2 Holes in the aluminum block to accommodate the testcells shall provide 1.0 mm max clearance for 38-mm outsidediameter glass tubes. The glass test cells shall fit into the blockto a depth of 225 6 5 mm.NOTE 2The original test blocks were made with spaces f
18、or ten testcells. Blocks with different number of holes are acceptable if otherrequirements are met.5.1.3 The heating system shall be geometrically and ther-mally balanced. For thermal balance, sizes and locations of theheaters are proportioned against heat losses.5.1.4 The block is cylindrical and
19、constructed from forgedaluminum. The block has a minimum thickness of 38 mm ofinsulation on all sides, top and bottom. An insulation ofthermally efficient ceramic fiber material is suggested.5.1.5 The exterior jacket, sides and top are stainless steel orequivalent.5.1.6 The block is equipped with a
20、well for a thermocouplefor temperature control and measurement, and a thermometerwell for temperature calibration.5.2 Temperature Control System, as shown at lower left inFig. 1, to maintain the heating block at a set temperature.5.2.1 The temperature controller shall be capable of main-taining the
21、block temperature within 60.5C of the desired testtemperature for the duration of the test. The preferred control-ler shall have proportional and integral control modes, and aheater malfunction alarm.FIG. 1 Universal Oxidation Test ApparatusD48710625.2.2 The range for operation is from at least 50 t
22、o 375C.(WarningAn adjustable deviation alarm that automaticallyshuts down the system if temperature varies outside presetlimits is desirable as a safety feature and to avoid erroneous testresults. A separate adjustable high temperature monitor andshutoff is desirable as a safety device.)5.2.3 Temper
23、ature control and uniformity is the most im-portant parameter affecting test result precision. Therefore, theheating system design is critical. Temperature from hole-to-hole and at all sides of each hole in the block shall be uniformwithin the 0.5C tolerance of the total system.5.3 Gas Flow Control
24、System, as shown in Fig. 1, to provideair or other gases to each test cell.5.3.1 A gas flow controller is required for each test cell, toprovide air or other desired gases. (WarningIf reactive gasesare to be used in the test procedure, all fittings in the gascontrol system must be compatible with th
25、ese gases.)5.3.2 The standard gas flow range shall be from 1.5 to 13L/h. Flowmeters shall have a scale length sufficiently long topermit accurate reading and control to within 65 % of fullscale. Floats and tubes may be interchangeable for alternate gasflow ranges.5.3.3 The system shall have a pressu
26、re regulator to provideconstant inlet pressure and 10 flow indicators with individual,integral needle valves with regulating stems for flow adjust-ment.5.3.4 The total system accuracy shall meet or exceed thefollowing tolerances:5.3.4.1 Inlet pressure regulator within 0.34 kPa (0.05 psig)of setpoint
27、,5.3.4.2 Total flow control system reproducibility within 7 %of full scale, and5.3.4.3 Repeatability of measurement within 0.5 % of fullscale.5.4 Alternative DesignsThe equipment in 5.1-5.3 repre-sents a preferred configuration. Alternative apparatus designsfor sample heating, and for temperature an
28、d flow control shallbe acceptable providing they are shown to maintain tempera-ture and gas flow within the specified limits.5.5 Glassware (Note 3), is used to contain the test sample,deliver gas into the sample, and collect, carry off or returncondensable volatiles.NOTE 3Not all glassware is used i
29、n a single test procedure.5.5.1 Test Cell, borosilicate glass, standard wall; 38-mmoutside diameter, 300 6 5-mm length, with open end fittedwith a 34/45 standard-taper, ground-glass outer joint (Note 4).See Fig. 2.NOTE 4Initial lots of glassware were made with 45/50 standard-taper,ground-glass joint
30、s. These are also acceptable for test work; however, the34/45 joints are preferred.5.5.2 Condenser, Allihn-Type, borosilicate glass, 33065-mm jacket, 34/45 standard-taper ground-glass inner joint onlower end. Upper opening must admit gas delivery tube. SeeFig. 2.5.5.3 Gas Inlet Tube I, 8-mm outside
31、diameter, 850 6 5mmlong, lower end with fused capillary 1.5 to 3.5 mm insidediameter. The capillary bore shall be at 15 6 1 mm long. Thelower tip is cut at a 45 angle. The gas inlet tube mayoptionally include a glass ring 15 mm in diameter to supportwasher-type catalysts, or the support ring (see 5.
32、5.8), fromwhich catalyst specimens may be suspended. The position ofthe ring on the gas inlet tube shall be specified in the testmethod requiring such catalyst support. The gas inlet tube I isillustrated in Fig. 2 with a glass ring suitable for support ofwasher-type catalyst.5.5.3.1 The 850-mm tube
33、is required for testing configura-tions using the condenser and sampling head or the interme-diate head in order that the tube extend beyond the top of thecondenser so that a gas supply hose can be attached. A tube ofshorter length may be substituted when other assemblies areused, provided it is lon
34、g enough to attach the gas supply.5.5.4 Gas Inlet Tube II, 8-mm outside diameter 455 6 5mmlong, lower tip cut at 45 angle. The top 50 mm of the tube mayoptionally be bent at a 90 angle. See Fig. 2.5.5.5 Basic Head, with 34/45 standard-taper, ground-glassinner joint, opening for gas inlet tube, septu
35、m port for samplewithdrawal, and exit tube to conduct off-gases and entrainedvapors. Overall length shall be 125 6 5 mm. The head shallhave an adapter by which an air-tight seal may be made withthe gas inlet tube.3The septum port is preferably designed toaccept a flat polytetrafluoroethylene (PTFE)-
36、faced siliconeseptum such as used with gas chromatographic instrumenta-tion. See Fig. 3.5.5.6 Intermediate Head, with standard-taper inner joint atbottom for test cell and outer joint at top for condenser. Overalllength shall be 170 6 5 mm. The outlet for removal ofoff-gases and condensed liquids is
37、 located far enough belowthe gas-escape holes to ensure that condensed liquid will exitthrough the side tube rather than returning to the test cell. Aseptum port (same as in 5.5.5) is provided for sample with-drawal. See Fig. 3.5.5.7 Sampling Head, with standard-taper inner joint atbottom for test c
38、ell and outer joint at top for condenser. Overall3A Wheaton-type thermometer adapter is suitable, with an O-ring seal. Allwetted parts should be of poly-tetrafluoroethylene (PTFE) or similar inert material.FIG. 2 ApparatusD4871063length shall not exceed 175 mm. A septum port (same as in5.5.5) is pro
39、vided for sample withdrawal. See Fig. 3.5.5.8 Support Ring, 9.5-mm inside diameter, 12.7-mm out-side diameter, 7 mm long, to fit on inlet tube I fitted withhigh-mounted glass ring. Four glass hooks are spaced at 90intervals from which catalyst coupons may be suspended. SeeFig. 3.5.5.9 Spacer Ring, 9
40、.5-mm inside diameter, 12.7-mm out-side diameter, 7 mm long, to fit on inlet tube I fitted withlow-mounted glass ring. The spacer is added to separate metalwashers used as catalyst and corrosion test specimens. See Fig.3.6. Procedure6.1 Test Conditions:6.1.1 Stability tests can be run for a fixed ti
41、me period, withmeasurement of selected parameters at the end of the testperiod or at intervals throughout the test.6.1.2 Stability tests can be run until a predetermined failurepoint, with measurement of selected parameters to determinefailure. Samples of fluid are withdrawn at intervals to measurec
42、hanges in the parameters.6.1.3 Fixed time tests are convenient for setting perfor-mance specifications; variable time tests can offer more usefulinformation in screening tests and evaluating formulationchanges.6.2 Possible test parameters that can be monitored include:6.2.1 Change in acid number (Te
43、st Methods D 664, D 974,D 3339,orD 5770),6.2.2 Change in precipitation number (Test Method D91),6.2.3 Change in viscosity (Test Method D 445),6.2.4 Change in color of fluid (Test Methods D 156 orD 1500),6.2.5 Evaporation loss from test fluid,6.2.6 Formation of an insoluble sludge,6.2.7 Formation of
44、a spot on a test blotter,6.2.8 Formation of varnish,6.2.9 Change in weight of catalyst specimens,6.2.10 Change in appearance of catalyst specimens,6.2.11 Weight of material volatilized from sample, and6.2.12 Acid number of volatilized material (Test MethodD 3339 or D 5770).7. Keywords7.1 accelerated
45、 testing-petroleum products; gear oil-stabilitytest apparatus; hydraulic oil-stability test apparatus; oxidationtesting-petroleum; stability-oxidation; stability-thermal; tur-bine oil-stability test apparatus; universal oxidation testapparatusSUMMARY OF CHANGESSubcommittee D02.09 has identified the
46、location of selected changes to this standard since the last issue(D 487100) that may impact the use of this standard.(1) Added Test Methods D 5763, D 5846, and D 6514 toSection 2.(2) Added 4.2 to include Test Methods D 5763, D 5846, andD 6514.ASTM International takes no position respecting the vali
47、dity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subj
48、ect to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquar
49、ters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610
