1、Designation: C447 15Standard Practice forEstimating the Maximum Use Temperature of ThermalInsulations1This standard is issued under the fixed designation C447; 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 practice covers estimation of the maximum usetemperature of thermal insulation including loose fill, blanket,block, board, a
3、nd preformed pipe insulation. It is based uponselected performance criteria, and characterization of productproperties during and after use conditions.1.2 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that
4、 are provided for information onlyand are not considered standard.1.3 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 app
5、lica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C165 Test Method for Measuring Compressive Properties ofThermal InsulationsC167 Test Methods for Thickness and Density of Blanket orBatt Thermal InsulationsC168 Terminology Relating to Thermal InsulationC17
6、7 Test Method for Steady-State Heat Flux Measure-ments and Thermal Transmission Properties by Means ofthe Guarded-Hot-Plate ApparatusC203 Test Methods for Breaking Load and Flexural Proper-ties of Block-Type Thermal InsulationC302 Test Method for Density and Dimensions of Pre-formed Pipe-Covering-Ty
7、pe Thermal InsulationC303 Test Method for Dimensions and Density of Pre-formed Block and BoardType Thermal InsulationC335/C335M Test Method for Steady-State Heat TransferProperties of Pipe InsulationC411 Test Method for Hot-Surface Performance of High-Temperature Thermal InsulationC421 Test Method f
8、or Tumbling Friability of PreformedBlock-Type and Preformed Pipe-Covering-Type ThermalInsulationC518 Test Method for Steady-State Thermal TransmissionProperties by Means of the Heat Flow Meter ApparatusD1621 Test Method for Compressive Properties of RigidCellular PlasticsD1622/D1622M Test Method for
9、 Apparent Density of RigidCellular Plastics3. Terminology3.1 Definitions contained in Terminology C168 shall beused in this practice.4. Summary of Practice4.1 Dimensions, weight and other pertinent properties of theinsulation are measured before, during, and after exposure to ahot surface.4.2 Proper
10、ties during and after exposure, and, in some cases,the degree of change in properties are reported for use inestablishing the maximum service temperature of the insula-tion.5. Significance and Use5.1 This practice is intended for use as a guide in evaluatingthe behavior of insulations at elevated te
11、mperatures, and injudging suitability for use under the conditions of an intendedapplication. It is not intended for acceptance or certificationtesting on a lot basis.5.2 No single test for estimating maximum use temperaturecan be used that will apply to all types of insulations, nor canany single m
12、aximum use temperature be applied to anyinsulation that will be applicable under all possible conditionsof use. Maximum use temperature depends on thickness,temperature gradient, heating rate, and other factors. When thevarious test methods listed herein are employed, the test resultsserve as guides
13、 and, as such, shall be applied with good1This practice is under the jurisdiction of ASTM Committee C16 on ThermalInsulation and is the direct responsibility of Subcommittee C16.31 on Chemical andPhysical Properties.Current edition approved Sept. 1, 2015. Published October 2015. Originallyapproved i
14、n 1959. Last previous edition approved in 2010 as C447 03R10. DOI:10.1520/C0447-03R10.2For 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 standards Document Summary
15、 page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1engineering judgment in arriving at an acceptable temperaturelimit for the products and applications being considered.5.3 The criteria used to establish acceptab
16、le performance isprovided in the material specification or as agreed upon by thepurchaser and seller.5.4 In most cases, the properties covered by the applicablematerial standards (for example, thermal transmission,strength, and so forth) are the properties important to the enduse of the product. Maj
17、or changes in those properties resultingfrom in-service conditions often causes failure or substandardperformance of the installed system.5.5 Unless removal and reuse of the insulation is an impor-tant consideration, properties that relate primarily to handlingand installation shall be eliminated fr
18、om the evaluation.NOTE 1Installation assemblies: some systems create conditions thataffect the performance from the data obtained in the test procedures of thispractice.5.6 The listing of a test procedure in this practice does notimply that the performance of that particular procedure isrequired. On
19、ly those tests which are relevant to the require-ments of the application involved, or which are agreed upon bythe purchaser and the seller are preformed.5.7 Most of the changes that occur in the functionallyimportant characteristics of all types of thermal insulationduring service result from chang
20、es in the matrix or bindersystem first, followed by changes in the bulk filler materialswhere such fillers have been used.5.7.1 In general, these changes are temperature-dependentand the major portion of the change takes place quickly oncethe critical temperature has been reached.5.7.2 Typically, or
21、ganic thermoplastic materials or binderswill change in the 140 to 240F (60 to 116C) temperaturerange. Thermosetting organic materials or binders will start todeteriorate above 350F (177C). Hydrated inorganic binderssuch as clays, Portland and lumnite cements, gypsum, sodiumsilicates, oxysulfates, an
22、d oxychlorides lose varying amountsof water of crystallization at temperatures from 250 to 900F(121 to 482C) depending on the compound. Glass fibers andglass foams start to sinter around 1000F (538C). Rock or slagwools, perlite and refractory fibers occassionally show changeat temperatures in excess
23、 of 1300F (704C).5.8 If, after testing specimens exposed to the maximumservice temperature, additional tests are made of specimensexposed to intermediate temperatures (third or quarter points inthe full service temperature range), the results of such tests,when plotted with proper curve-fit techniqu
24、es, give indicationsof changes in product characteristics throughout the servicerange. These results are used to bracket the temperature rangewithin which a change has occurred (for example, significantchange in slope of curve).5.9 Some properties of thermal insulations containingtrapped gases other
25、 than air change with time at different ratesdepending on the age, thickness, facing and boundary condi-tions. Elevated temperature exposure often accelerates thesechanges. In many cases changes in properties continue over avery long period of time. It is beyond the scope of thisrecommended practice
26、 to establish a minimum time period forevaluation of long-term changes.6. Test Conditions6.1 If required, testing shall begin at the hot-face tempera-ture of the desired application or the maximum use temperaturethat is claimed. When there has been significant deteriorationof the properties tested d
27、uring or after exposure at themaximum hot-face temperature, additional specimens will beexposed at lower temperatures (third or quarter points of thetemperature range from ambient to maximum) to establish themaximum hot-face temperature. Additional tests shall be madeuntil enough data have been obta
28、ined to establish acceptableperformance.6.2 The criteria necessary to establish acceptable perfor-mance by any of the methods described shall be as provided inthe material specification or as agreed upon between thepurchaser and seller. For example, the specification of aminimum compressive strength
29、 or a maximum percent dimen-sional change as criterion for estimating the maximum usetemperature.6.3 With anisotropic materials that are produced initially inlarge cross-sections and mechanically fabricated in subsequentoperations to produce boards or preformed pipe insulation, it isadvisable to exa
30、mine properties of interest in all three axes.6.4 Since soaking heat exposure seldom occurs under “asinstalled” conditions, and such exposure often produces mis-leading results test specimens shall be conditioned usinghot-face-/cold-face methods. Limit soaking heat exposure topreliminary evaluation
31、and quality control testing.6.5 The elevated temperature exposure time required toeffect major change depends on the type of product beingtested. Preliminary trials shall be made to establish the mini-mum hot surface exposure time required for a particularinsulation material. The minimum exposure ti
32、me has beenreached when the property of interest shows no more thanexpected random variations in three consecutive readings takenat three hour intervals.7. Test Specimens7.1 The test specimens shall be selected to be representativeof the material under evaluation. Original surfaces shall beretained
33、at least on the hot face of the specimens.7.2 Other specimen dimensions shall conform to the re-quirements of Test Method C411. Where further fabrication ofthe specimen after exposure is not practical, additionalspecimens, precut to the required size, shall be exposedseparately.8. Procedure8.1 Hot S
34、urface PerformanceTest and report the hotsurface performance of the insulation in accordance with TestMethod C411 with the following exceptions and additions.8.1.1 The thickness of the test specimens shall be theintended thickness of the application or the manufacturersrecommended minimum and maximu
35、m thickness for the testC447 152temperature. The number of layers of insulation exposed andtested shall be representative of the intended application or themanufacturers recommendation.8.1.2 Unless a specific heat-up period is specified theintended application, included in the material specification
36、 orrecommended by the manufacturer, the apparatus shall bepreheated to the test temperature using a blank specimen ofsimilar thermal transmission properties. Once the test tempera-ture has been reached, the blank specimen shall be removedand the test specimen(s) quickly applied to the hot surface.8.
37、1.3 The hot-face temperature shall be the service tempera-ture being evaluated.8.1.4 Where specific fastening methods are contained in thematerial specification, the insulation shall be held against thehot surface by means representing these fastening methods, forexample, screws, exterior frames. Th
38、e attachment method shallbe included in the report.8.1.5 Measure and report the dimensions and weight of thespecimens before and after exposure. Suitable measuringinstruments and procedures can be found in Test MethodsC167, C303 or D1622/D1622M, and C302 for blankets orbatts, block or board, and pre
39、formed pipe insulation respec-tively. Dimensions, and changes in dimensions, of the hot andcold faces shall be measured and reported.8.1.6 Record the temperature rise during heat-up at 1-in.(25-mm) increments through the thickness of the specimen todetect of endothermic or exothermic reactions withi
40、n theinsulation. Temperature shall be recorded continuously, or at amaximum interval of five minutes, until the steady-state isreached. Suitable temperature sensors with a maximum re-sponse time of one minute and an accuracy of 6 1C shall beused. The sensors shall be located at the top center of the
41、specimen for preformed pipe covering.8.2 Thermal Transmission PropertiesTest and report thethermal transmission properties of the insulation in accordancewith Test Methods C177 or C518 for blanket, felt, block orboard insulation. Test Method C335/C335M shall be used forpreformed pipe insulation.8.2.
42、1 The test thickness shall be 112 612 in. (38 6 13 mm)for Test Methods C177 or C518. For Test Method C335/C335M the test thickness is adjusted as required to achieve theproper cold-face temperature.8.2.2 The hot-face temperature shall be the service tempera-ture being evaluated.8.2.3 The cold-face t
43、emperature shall be representative ofthe intended application or a maximum of 200F (93C).8.2.4 Prior to measurement the specimens shall be exposedon the test apparatus at the test temperature for the minimumperiod determined in 6.5. Separate hot-surface exposure is notrequired.NOTE 2Where cyclic ope
44、rating conditions are anticipated, it isprudent to confirm thermal transmission properties at lower temperaturesfollowing exposure to the maximum hot face temperature.8.3 Other PropertiesTest and report the other pertinentproperties of the insulation following hot-surface exposure.8.3.1 Specimens sh
45、all be obtained from material exposed inaccordance with 7.1. Where further fabrication after exposureis not possible, additional specimens precut to the required sizeare exposed separately while maintaining the thickness andother exposure parameters of 7.1.8.3.2 The full thickness of the exposed spe
46、cimen shall betested. Where it is impractical to test the specimens at fullthickness, carefully slit and test two or more layers. The resultsof tests on each layer shall be reported separately and identifiedas to the original location through the thickness from hot faceto cold face.8.3.3 Where it is
47、 useful to compare the properties of theinsulation material before and after exposure, the specimensused for“ before exposure” tests shall be of the same size andselected from similar material as those used for the “afterexposure” test.8.3.4 Depending on the application, the following propertiesare
48、useful in estimating the suitability of the insulation follow-ing exposure to the test-service temperature. Additional perti-nent properties are found in the applicable material specifica-tion and the manufacturers literature. The provisions ofSection 5 shall be considered in selecting properties fo
49、r testing.8.3.4.1 Compression PropertiesTest Method C165 or TestMethod D1621.8.3.4.2 Flexural StrengthTest Methods C203.8.3.4.3 Water/Moisture Absorption/Repellency/WickingAbilityRefer to the appropriate material specification.8.3.4.4 Tumbling FriabilityTest Method C421.9. Keywords9.1 hot-surface performance; maximum-use temperature;thermal insulationASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determinatio
