1、Designation: D7840 12Standard Test Method forFoaming Tendencies of Non-Aqueous Engine Coolants inGlassware1This standard is issued under the fixed designation D7840; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a simple glassware test forevaluating the tendency of non-aqueous engine coolants tofoam under labo
3、ratory controlled conditions of aeration andtemperature.1.2 UnitsThe values stated in SI units are to be regardedas the standard. No other units of measurement are included inthis standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is
4、 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. For specificwarning statements, see 7.2 and 7.3.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent Wa
5、terE1 Specification for ASTM Liquid-in-Glass ThermometersE128 Test Method for Maximum Pore Diameter and Perme-ability of Rigid Porous Filters for Laboratory UseE230 Specification and Temperature-Electromotive Force(EMF) Tables for Standardized Thermocouples3. Terminology3.1 Definitions of Terms Spec
6、ific to This Standard:3.1.1 break time, ntime required for the foam to collapse(after the air supply has been shut off) to the first appearance ofan “eye” on the surface of the test solution.3.1.2 eye, nappearance of foam-free area on the surface ofthe test coolant surrounded by a ring of foam cling
7、ing to thecylinder walls.4. Summary of Test Method4.1 The non-aqueous coolant of interest is blown with air ata constant rate for 5 min while maintained at a constanttemperature of 88 6 1C by means of a suitable temperaturebath. The volume of foam and the time for such foam to breakare measured.5. S
8、ignificance and Use5.1 In the test method, coolants generally will be distin-guished that have a tendency to foam excessively from thosethat are suitable for further evaluation to determine perfor-mance in actual service.NOTE 1In use, the foaming tendency of a coolant solution may beincreased by ser
9、vice aging or contamination. A properly functioningpressure cap will tend to suppress foaming in coolant solutions.6. Apparatus6.1 Container, a 500-mL graduated container of heat-resistant glass having a diameter of 45 to 50 mm and a lengthof 380 mm.6.2 Temperature Bath, a heat-resistant glass conta
10、iner largeenough to permit immersion of the graduated container at leastto the 350-mL graduation mark. A 4000-mL beaker is satisfac-tory.6.3 Heat Source, any heating system capable of maintaininga uniform bath temperature of 61C. A 750-W electric hotplate is satisfactory.6.4 Aerator Tube, a 25.4-mm
11、diameter spherical gas-diffuser stone3made of fused crystalline alumina grain thatmeets the following specifications when tested in accordancewith the method given in Annex A1:Maximum pore diameter, m Not greater than 80Permeability at a pressure of 2.45 kPa,mL of air/min3000 to 64006.5 Temperature
12、Measuring Instrument (EnvironmentallySafe Thermometer or Thermocouple)An ASTM Partial Im-mersion Temperature Measuring Instrument having a rangefrom 20 to 150C (0 to 302F) and conforming to the1This test method is under the jurisdiction of ASTM Committee D15 on EngineCoolants and Related Fluids and
13、is the direct responsibility of SubcommitteeD15.22 on Non-Aqueous Coolants.Current edition approved Dec. 1, 2012. Published January 2013. DOI: 10.1520/D7840-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of
14、 ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3For information on aerator supplier and specifications, contact ASTM Subcom-mittee D15.06 through ASTM International Headquarters.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West
15、 Conshohocken, PA 19428-2959. United States1requirements for Thermometer 1C (1F), as prescribed inSpecification E1 or Thermocouple as summarized in Specifi-cation E230.6.6 Air Supply, a clean and dry source, free from grease andother contaminants, capable of maintaining the prescribed flowrate throu
16、gh the diffuser stone.6.7 Timer, a stop watch or suitable timing device accurate to60.2 s.6.8 Vent, a three-way stopcock inserted in the metered airsupply line immediately ahead of the aerator tube.6.9 Typical Assembly Setup, A typical apparatus using ahot-plate heat source is shown in Fig. 1.7. Rea
17、gents and Materials7.1 Purity of WaterUnless otherwise indicated, referencesto water means reagent water as defined by Type II ofSpecification D1193.7.2 Acetone, for flushing and drying the test equipment.(WarningAcetone is extremely flammable.)7.3 Cleaning BathRefers to an acid or base cleaningsolu
18、tion used to clean glassware between tests. The choice ofcleaning baths depends on individual needs. For example,Nochromix and alcoholic sodium (potassium) hydroxide arecommon acid and base cleaning baths, respectively.4(WarningThe cleaning baths are strong oxidants and strongacid and base, respecti
19、vely. Avoid contact with skin, eyes, andclothing. Do not breathe vapor. Handle in a fume hood.)4Nochromix is an inorganic oxidizer that contains no metallic ions. The whitepowder is dissolved in water and mixed with concentrated sulfuric acid, giving asolution that reportedly is more strongly oxidiz
20、ing than chromic acid. The solesource of supply of Nochromix known to the committee at this time is GodaxLaboratories Inc., PO box 422, Cabin John, MD 20818. If you are aware ofalternative suppliers, please provide this information to ASTM InternationalHeadquarters. Your comments will receive carefu
21、l consideration at a meeting of theresponsible technical committee, which you may attend.FIG. 1 Schematic Drawing of Apparatus for Glassware Foam TestD7840 1228. Test Coolant8.1 The non-aqueous coolant is intended to be tested as-is,without dilution or adulteration of any kind.9. Conditioning9.1 Tes
22、t TemperatureThe temperature bath shall be kept ata constant volume (350- to 375-mL mark of the graduatedcylinder) throughout the test. The reference and test coolantsshall be maintained at 88 6 1C throughout.9.2 Aeration RateThe aeration rate shall be 1000 6 25mL/min.9.3 Number of TestsThe non-aque
23、ous test coolant shall betested in triplicate using a fresh sample of the non-aqueous testcoolant from the same lot for each test. The entire containerand aerator tube (see 6.1 and 6.4) shall be cleaned scrupulouslyprior to the first test and between each subsequent test. Thesame container and aerat
24、or tube shall be used in all of the tests.The container shall be cleaned in a cleaning bath as defined by7.3, and the aerator tube shall be immersed first in acetone andflushed back and forth, and then in water, and flushed back andforth using vacuum and air pressure. The entire assembly shallbe tho
25、roughly rinsed with Type II water and then dried beforeeach test.NOTE 2Scrupulous cleaning of the glassware, aerator tube, anddiffuser stone before the initial test and between tests will reduce thepotential carryover of antifoam or other contaminants from previous teststhat can interfere with test
26、reproducibility.10. Procedure10.1 Heat 145 mL of the non-aqueous test coolant to 88Cin the container positioned in the temperature bath. Immersethe aerator tube and read the level of the liquid to the nearest5 mL. Measure the temperature with the temperature measur-ing instrument inside the graduate
27、d container.10.2 Connect air supply, position stopcock to permit air flowto aerator tube, and adjust the air flow rate of 1000 mL/minusing a manometer or other suitable instrument for accuratelymeasuring volumes of air flow.10.3 The timing of the 5-min aeration period shall start atthe appearance of
28、 the first bubbles in the test coolant.10.4 At the end of 5 min, measure the volume of foam at thehighest level and subtract the initial volume read after insertingthe aerator tube. Read the foam volume to the nearest 5-mLgraduation.10.5 Relieve the air pressure by positioning the three-waystopcock
29、to shut off the air supply and vent the inlet tube to theatmosphere simultaneously and record precisely (60.2 s) thetime for the foam to collapse to the first appearance of an “eye”on the surface of the test coolant.11. Recording of Data11.1 The testing shall be done in triplicate using newnon-aqueo
30、us test coolant for each test run. The data shall berecorded as the tests progress in the format of Table 1.Iftheglassware is clean at the beginning of each run, i.e., free ofresidual defoamer, there should be no discernible uptrend in thedata recorded as the tests progress. If there is a discernibl
31、euptrend in either the foam volume or the break time, clean theapparatus as previously described and perform a fourth test.12. Averaging the Results and Presentation12.1 If the test consists of three iterations, average the threeresults. If the test consists of four iterations, average the lasttwo r
32、esults. Present the results in a format similar to that shownin Table 1.13. Precision and Bias13.1 A statement on precision and bias is under review, andround robin testing is currently in progress.14. Keywords14.1 engine coolants; foaming; glassware; non-aqueousANNEX(Mandatory Information)A1. TEST
33、FOR MAXIMUM PORE DIAMETER AND PERMEABILITY OF STONE DIFFUSERS(BASED ON TEST METHOD E128 AND SPECIFICATION E1)TABLE 1 Test ResultsTest RunFoam Volumeat 5 min, mL“Break Time”Appearance of “Eye”, s1234 (if needed)Average of 3Average of Last TwoD7840 123A1.1 DefinitionsA1.1.1 maximum pore diameter, ndia
34、meter in microme-tres of a capillary of circular cross section that is equivalent(with respect to surface tension effects) to the largest pore inthe diffuser under consideration.A1.1.2 permeability, nflow of air, in millilitres per minute,through the diffuser stone at air pressure of 2.5 kPa (250 mm
35、of water).A1.2 ApparatusA1.2.1 Apparatus for the maximum pore diameter determi-nation consists of a regulated source of clean, dry, compressedair; a U-tube water manometer of sufficient length to read apressure differential of 800 mm; and a cylinder of a sizesufficient (250 mL is suitable) to immers
36、e easily a diffuserstone to a depth of 100 mm.A1.2.2 Additional apparatus for permeability determinationconsists of a gas volume meter of sufficient capacity to measureflow rates of at least 6000 mL/min and a filtering flask largeenough that 25.4-mm diameter diffuser stones will passthrough the neck
37、. The flask shall be fitted with a rubber stopperwith a single hole to admit the air-inlet tube (see Fig. A1.1).A1.3 ProcedureA1.3.1 Maximum Pore DiameterSupport the clean dif-fuser by an air-inlet tube at a depth of 100 mm as measured tothe top of the stone in distilled water in a cylinder and allo
38、w itto soak for at least 2 min. Connect the air-inlet tube to acontrollable source of clean, compressed air and a manometeras shown in Fig. A1.2. Increase the air pressure at a rate ofabout 50 mm of water/min until the first dynamic bubble passesthrough the filter and rises through the water. The fi
39、rst dynamicbubble is recognized by being followed by a succession ofadditional bubbles. Read the water level in both legs of themanometer and record the difference as the pressure, p. Theuniformity of the distribution of pores approaching maximumpore size may be observed by gradually increasing the
40、airpressure and noting the uniformity with which streams ofbubbles are distributed over the surface.A1.3.1.1 Calculate maximum pore diameter, D,inmicrometres, as follows:D 5 29 225(p 2 100) (A1.1)A1.3.2 PermeabilityConnect the clean, dry diffuser stoneto a controllable source of clean, dry, compress
41、ed air and placeit in a filtering flask connected to a suitable flowmeter as shownin Fig. A1.1. Adjust the pressure differential to 2.5 kPa (250mm of water) and measure the rate of flow of air through thediffuser stone in millilitres per minute. Depending on thesensitivity of the flowmeter used, thi
42、s observation may bemade for a suitably longer period than the average flow rate perminute recorded.FIG. A1.1 Apparatus for Measuring PermeabilityD7840 124ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard.
43、 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 subject to revision at any time by the responsible technical committee and must be reviewed e
44、very 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 Headquarters. Your comments will receive careful consideration at a meeting of theresponsible tec
45、hnical 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 Conshoho
46、cken, 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), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).FIG. A1.2 Apparatus for Measuring Maximum Pore SizeD7840 125
