1、Designation: D2758 94 (Reapproved 2009)Standard Test Method forEngine Coolants by Engine Dynamometer1This standard is issued under the fixed designation D2758; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisi
2、on. 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 full-scale clean engine testdesigned to evaluate corrosion protection and inhibitor stabilityof engine
3、coolants under simulated heavy-duty driving condi-tions.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresp
4、onsibility 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. Specific hazardsstatements are given in Section 6.2. Referenced Documents2.1 ASTM Standards:2D1121 Test Method for Reserve Alkalinity
5、 of Engine Cool-ants and AntirustsD1287 Test Method for pH of Engine Coolants and Anti-rustsD1384 Test Method for Corrosion Test for Engine Coolantsin GlasswareG1 Practice for Preparing, Cleaning, and Evaluating Corro-sion Test Specimens2.2 Federal Standard:3CFR Title 29 OSHA Regulations3. Summary o
6、f Test Method3.1 This test method involves the operation of a standardpassenger car engine on a dynamometer stand under constantspeed, load, and coolant temperature conditions for a total of700 h. The performance of the coolant is judged by examina-tion of (1) coolant samples, (2) metal corrosion sp
7、ecimens, and( 3) cooling system components.4. Significance and Use4.1 This test method provides a laboratory technique ca-pable of reproducing the complex environmental stresses acoolant encounters under actual engine operating conditions.The test method provides improved discrimination over glass-w
8、are and simulated service tests and improved correlation withfield service. Although the test method is particularly valuablefor developing coolants for increased service requirements, itremains that field testing is necessary to evaluate coolantperformance completely.5. Apparatus5.1 Test Engine The
9、 test engine shall be a volumeproduction passenger car engine of cast iron or aluminumconstruction. Engine speed and brake horsepower should becalculated and adjusted to be equivalent to a 96.5 km/h (60mph) level road load. Aluminum accessories, such as coolantpump and timing chain cover, are option
10、al. The engine shall beequipped with a matching radiator and pressure cap. A coolantoverflow reservoir and closed-system pressure cap are op-tional, except when specified by the manufacturer. Assemblethe test components to provide a complete cooling system. Therelative positioning of the radiator an
11、d engine should duplicate,as closely as practicable, the mounting in the automobile withthe fan omitted. All radiator hose lengths should be held to aminimum. The radiator shall be cooled by forced air.5.2 Instrumentation and Control (See Fig. 1)Run theengine on a test stand coupled to an engine dyn
12、amometer withappropriate accessories for control of the designated operatingconditions. Measure engine coolant temperature out of theengine at a point immediately adjacent to the coolant outlet.Measure manifold vacuum, oil pressure, and exhaust pressureat appropriate points and monitor them througho
13、ut the test inorder to ensure proper engine performance. Install a pressuregage in the outlet tank of a crossflow radiator or the top tank ofa downflow radiator to read the gage pressure.5.3 Corrosion Measurements:5.3.1 Evaluate corrosion protection using metal specimens.The specimen arrangement sha
14、ll be basically that used in TestMethod D1384. The specimen bundle is shown in Fig. 2.Preparation, cleaning, and weighing of the metal specimens are1This test method is under the jurisdiction of ASTM Committee D15 on EngineCoolants and is the direct responsibility of Subcommittee D15.10 on Dynamomet
15、erand Road Tests.Current edition approved Nov. 1, 2009. Published December 2009. Originallyapproved in 1968 as D2758 68 T. Last previous edition D2758 94 (2003). DOI:10.1520/D2758-94R09.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceas
16、tm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from the Occupational Safety and Health Administration, 200Constitution Ave., N.W., Washington, DC 20008.1Copyright ASTM International, 100 Barr Harbor Drive, PO Bo
17、x C700, West Conshohocken, PA 19428-2959, United States.described in Test Method D1384 and Practice G1. Eachspecimen bundle shall be held in a canvas-reinforced phenolictube (see Fig. 3) which, in turn, is contained in a capsule. Usetwo types of specimen capsules: full-flow and bypass. Installthe fu
18、ll-flow capsule in the upper radiator hose, and connect thebypass capsule across the heater taps of the engine. Details ofthe capsules are shown in Fig. 4 and Fig. 5. The full-flowcapsule shall contain three sets of specimens; weigh andreplace one set with a fresh set at 100-h increments, and weight
19、wo sets at the conclusion of the test. The bypass capsule shallcontain three sets of specimens; clean, weigh, and replace thefirst set at 100-h increments. Clean and weigh the second set at400 h. Replace, clean, and weigh this set at the end of the test.Clean and weigh the third set at the end of th
20、e test.5.3.2 Position the full-flow capsule in the upper radiatorhose at a point below the radiator coolant level.5.3.3 The bypass capsule should be located in close prox-imity to the engine in order to avoid excessive coolanttemperature drop.5.3.4 Equip the bypass capsule with a temperature-measuri
21、ng device to assure that normal flow is being main-tained. (Atemperature drop from normal operating temperatureindicates an obstruction in the bypass circuit.) A mountingbracket attached to the radiator stand is recommended. Mountthe capsule below the radiator coolant level in a verticalposition. Co
22、nnect the bottom fitting of the capsule with arubber hose to the standard heater supply nipple, and connectthe top fitting to the return nipple on the coolant pump.5.4 Fuel and Crankcase OilBecause of the extendedduration of this test, it is suggested that high-quality fuels andmotor oils be selecte
23、d to control combustion problems andachieve maximum valve life.6. Precautions6.1 Safety Precautions:6.1.1 CoolantAll coolant concentrates and their solutionsshould be considered harmful or fatal if swallowed.6.1.2 Specimen CleaningWhen cleaning aluminum speci-mens with chromic acid/orthophosphoric a
24、cid solution, usefume hood.6.1.3 Personal ProtectionAppropriate personal protectionequipment (safety glasses, gloves, etc.) should be worn at alltimes when working with hot, pressurized engine systems. Ingeneral, engine speed should be lowered to 1000 rpm at noload, and the temperature and pressure
25、on the cooling systemshould be lowered to a level below the boiling point of thecoolant before approaching the engine. To avoid possibleburns, care should be exercised in venting and opening theradiator pressure cap.6.1.4 Safety Guards Sturdy safety guards must be usedfor the fan belt, pulleys, coup
26、lings, and drive shaft (see OSHARegulations, CFR Title 29).FIG. 1 Air Cooling SetupD2758 94 (2009)26.1.5 Maintenance of Physical EquipmentIn the operationand planning of the dynamometer test facility, adequate fore-thought must be given to the fuel system, exhaust system, firehazards, and general ho
27、usekeeping in order to maintain a highNOTE 1AAlternate specimen bundles are shown in Test Method D D13841384.Metric Equivalentsin. 0.0601161831614176471612 12mm 1.52 1.59 3.18 4.76 6.35 6.75 11.11 12.7 25 51FIG. 2 Corrosion Specimen BundleMetric Equivalentsin.31614716 11516 2116 212mm 4.76 6.35 11.1
28、1 49.21 52.39 63.5NOTE 1To achieve snug fit of the specimen bundle in the tube, add insulating washers as necessary under the brass nut on the specimen bundle.FIG. 3 Specimen Bundle SleeveD2758 94 (2009)3level of safety standards. For example, checks for leaks in thefuel, oil, and exhaust systems mu
29、st be made on a continuingbasis, and consideration must be given to the routing of a hotexhaust system in an area of combustible materials.7. Preparation of Apparatus7.1 Engine Reconditioning:7.1.1 Check the engine and recondition, if necessary, priorto each test run. For each new engine, prior to a
30、 series of tests,and those engines being reconditioned for further testing,install new cylinder head gaskets; the engine manufacturersrecommendations should be followed regarding the use ofgasket sealing compounds. When no specific recommendationis made by the engine manufacturer, the cylinder head
31、gasketsand other coolant sealing gaskets should be coated with anadhesive sealant. This will ensure against coolant and exhaustgas leakage at some advanced point in the test, possiblyvoiding the test and its results. A new radiator should beinstalled before each test. The cooling system should beche
32、cked for the following common defects: (1) cylinder headgasket leakage resulting in exhaust gas contamination of thecoolant, (2) air induction into the coolant due to a worn coolantpump seal, and (3) defective lower radiator hose connection.Methods of checking for these defects appear in Annex A1.7.
33、1.2 Clean the engine cooling system with a chelator-typecommerical cleaner (seeAnnexA2). Replace all hoses after thecleaning procedure, but before each test.7.2 Installation of Test Specimens and Coolant:7.2.1 Prior to the installation of the coolant, install a newaluminum coolant outlet (if the eng
34、ine is so equipped), alongwith a thermostat fixed in the full open position (see Note). Flatwashers should be used under the coolant outlet-attaching boltheads to minimize damage to the mounting flanges. Install thespecimen-containing capsules at this time.NOTE 1Thermostats of different manufacturer
35、s have different designminimum travel positions. “Full open” would mean the maximum travel.To block a thermostat open, the power element should be drilled andtapped for an adjusting screw, soldered into position and cut off. Neversolder the piston to the piston guide as this may cause damage orannea
36、ling of other thermostat components. To determine maximum travel,measure valve position equivalent to 11C (20F) above stamped openingtemperature; for example, 89C 1 11C 5 100C 192F 120F 5 212F!.7.2.2 Based upon careful measurement of the volume of thesystem, add a measured amount of concentrated coo
37、lantdirectly to the cooling system to provide a 40 volume %coolant solution when filled to overflow with water containingMetric Equivalentsin. 112 2214mm 38 50.8 57FIG. 4 Upper Radiator Hose Full Flow Specimen CapsuleMetric Equivalentsin38 214mm 9.5 57FIG. 5 By-Pass Specimen CapsuleD2758 94 (2009)41
38、00 ppm each of chloride, sulfate, and bicarbonate ions (seeAnnex A3). If desired, single-phase-inhibited coolant may bepremixed with corrosive water in a clean container and addedto the cooling system as a solution. Under no conditionspremix external to the cooling system at the initiation of thetes
39、t two-phase coolants containing polar oils. Before startingthe test and after installing test coolant, conduct a 103-kPa(15-psi) pressure leakage test to check for external coolantleakage at hoses, gaskets, and coolant pump.7.2.3 With the engine running at 1000 rpm no load and 93C(200F) coolant outl
40、et temperature, drain sufficient coolant tobring the radiator level from overflow to 19 mm (34 in.) belowthe pressure cap seat for down-flow radiators, and 38 mm (112in.) below the pressure cap seat for cross-flow radiators. (Whenradiator is equipped with an overflow reservoir and closed-system pres
41、sure cap, coolant level should be at the pressure capseat.) Replace radiator cap. Save the drained coolant, and addit to 2-L (2-qt) sample of premixed 40 % test coolant andcorrosive water solution to use as makeup throughout the test.8. Procedure8.1 Maintain the following test conditions throughout
42、thetest method, except for the inspections detailed in subsequentsections:Coolant 40 volume % concentration of test coolantin 100-100-100 corrosive waterCoolant outlet temperature 93 6 2C (200 6 3F) or optionalExhaust pressure 0 to 25.4 mm (0 to 1 in.) HgTest duration 700 hThermostat Fixed to remain
43、 full openRadiator cap Standard specification for the engine cool-ing systemCoolant level 19 mm (34 in.) below pressure cap seat fordown-flow radiators38 mm (112 in.) below pressure cap seat forcross-flow radiatorsAt pressure cap seat when radiator is equip-ped with an overflow reservoir and clos-ed
44、-system pressure capSpeed and brake hP Equivalent to 96.5 km/h (60 mph) levelroad load8.2 Perform periodic inspections throughout the test, asgiven in Table 1.9. Interpretation and Significance of Results9.1 The test method is intended to provide a more compre-hensive evaluation of coolant performan
45、ce than is obtainablewith glassware and stimulated service tests. Correlation withfield service is generally good for engines of similar design andmaterial, but depends to a significant degree on the investiga-tors ability to interpret test results in relation to field serviceexperience. Field servi
46、ce will inherently impose variations inseverity.9.2 The individual specimen weight loss values have limitedsignificance in terms of absolute corrosion protection withrespect to field service. Instead, they must be compared tobaseline values established with coolants of known fieldservice performance
47、. The comparative weight loss valuesencountered with those specimens that remain undisturbed forthe duration of the test indicate overall corrosion protection bythe test coolant. These specimens should be the most valuableto predict field service performance. The specimens, which arereplaced at pred
48、etermined intervals, and present a clean activesurface, may be used to predict extended coolant performanceas related to inhibitor depletion and formula degradation rate.A change in weight loss pattern may indicate coolant deterio-ration even though the solution characteristics and undisturbedspecim
49、en weight losses indicate a satisfactory condition.9.3 Reserve alkalinity depletion also may be used to evalu-ate coolant service life and performance, provided properprecautions in interpretation are observed. After an initialreduction due to inhibitor reaction on cooling system surfaces,the reserve alkalinity will normally decrease gradually with testhours. Variation from this general pattern is cause for investi-gation.9.4 The clean engine dynamometer test provides coolantevaluation under the duration, heat rejection, and other
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