1、Designation: C 447 03Standard Practice forEstimating the Maximum Use Temperature of ThermalInsulations1This standard is issued under the fixed designation C 447; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revi
2、sion. 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 practice covers estimation of the maximum usetemperature of thermal insulation including loose fill, blanket,block, board
3、, and preformed pipe insulation. It is based uponselected performance criteria, and characterization of productproperties during and after use conditions.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 t
4、his standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:C 165 Test Method for Measuring Compressive Propertiesof Thermal Insulations2C 167 Test Methods for Thickness and Densi
5、ty of Blanketor Batt Thermal Insulations2C 168 Terminology Relating to Thermal Insulation2C 177 Test Method for Steady-State Heat Flux Measure-ments and Thermal Transmission Properties by Means ofthe Guarded-Hot-Plate Apparatus2C 203 Test Methods for Breaking Load and Flexural Prop-erties of Block-T
6、ype Thermal Insulation2C 302 Test Method for Density of Preformed Pipe-Covering-Type Thermal Insulation2C 303 Test Method for Density of Preformed Block-TypeThermal Insulation2C 335 Test Method for Steady-State Heat Transfer Proper-ties of Horizontal Pipe Insulation2C 411 Test Method for Hot-Surface
7、 Performance of High-Temperature Thermal Insulation2C 421 Test Method for Tumbling Friability of PreformedBlock-Type Thermal Insulation2C 446 Test Method for Breaking Load and CalculatedModulus of Rupture of Preformed Insulation for Pipes2C 518 Test Method for Steady-State Heat Flux Measure-ments an
8、d Thermal Transmission Properties by Means ofthe Heat Flow Meter Apparatus2D 1621 Test Method for Compressive Properties of RigidCellular Plastics3D 1622 Test Method for Apparent Density of Rigid CellularPlastics33. Terminology3.1 Definitions C 168 shall apply to the terms used in thispractice.4. Su
9、mmary of Practice4.1 Dimensions, weight and other pertinent properties of theinsulation are measured before, during, and after exposure to ahot surface.4.2 Properties during and after exposure, and, in some cases,the degree of change in properties are reported for use inestablishing the maximum serv
10、ice temperature of the insulationmaterial.5. Significance and Use5.1 This practice is intended for use as a guide in evaluatingthe behavior of insulations at elevated temperatures, and injudging suitability for use under the conditions of an intendedapplication. It is not intended for acceptance or
11、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 maximum use temperature be applied to anyinsulation that will be applicable under all possible conditionsof use. Maximum use tempera
12、ture may depend on thickness,temperature gradient, heating rate, and other factors. When thevarious test methods listed herein are employed, the test resultsserve as guides and, as such, must be applied with goodengineering judgment in arriving at an acceptable temperaturelimit for the products and
13、applications being considered.1This 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 April 10, 2003. Published May 2003. Originallyapproved in 1959 . Last
14、previous edition approved in 2001 as C447 85 (2001)e1.2Annual Book of ASTM Standards, Vol 04.06.3Annual Book of ASTM Standards, Vol 08.01.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.3 The criteria used to establish acceptable p
15、erformance isprovided in the material specification or as agreed uponbetween the purchaser and seller.5.4 In most cases, the properties covered by the applicablematerial standards (for example, thermal transmission,strength, etc.) are the properties important to the end use of theproduct. Major chan
16、ges in those properties resulting fromin-service conditions can cause failure or substandard perfor-mance 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 from the e
17、valuation.NOTE 1Installation assemblies: some systems create conditions thatwill affect the performance from the data obtained in the test proceduresof this practice.5.6 The listing of a test procedure in this practice does notimply that the performance of that particular procedure isrequired. Only
18、those tests which are relevant to the require-ments of the application involved, or which are agreed uponbetween the 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 cha
19、nges 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 fairly quicklyonce the critical temperature has been reached.5.7.2 Typi
20、cally, organic 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, oxysul
21、fates, and oxychlorides will lose varyingamounts of water of crystallization at temperatures from 250 to900F (121 to 482C) dependent on the compound involved.Glass fibers and glass foams may start to sinter around 1000F(538C). Rock or slag wools, perlites and refractory fibers mayshow change at temp
22、eratures in excess of 1300F (704C)dependent on specific composition.5.8 If, after testing samples exposed to the maximumservice temperature, additional tests are made of samplesexposed to intermediate temperatures (third or quarter points inthe full service temperature range), the results of such te
23、sts,when plotted with proper curve fit techniques, may give someindication of changes in product characteristics throughout theservice range. These results may also be used to bracket thetemperature range within which a change has occurred (sig-nificant change in slope of curve).5.9 Some properties
24、of thermal insulations containingtrapped gases other than air change with time, and at differentrates, depending upon the age, thickness, facing and boundaryconditions. Elevated temperature exposure accelerates thesechanges. Changes in properties of these materials may continueover a very long perio
25、d of time, however, and it is beyond thescope of this recommended practice to establish a minimumtime period for evaluation of these long-term changes.6. Test Conditions6.1 If required, testing shall begin at the hot face tempera-ture of the desired application or that claimed as the maximumuse temp
26、erature. When there has been significant deteriorationof the properties tested during 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 thecritical tem
27、perature. Additional tests shall be made untilenough data have been obtained to establish acceptable perfor-mance.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 a
28、nd seller. For example, a minimum value ofcompressive strength or a maximum percent dimensionalchange might be specified as the criterion for estimating themaximum use temperature.6.3 With anisotropic materials that are produced initially inlarge cross-sections and mechanically fabricated in subsequ
29、entoperations to produce boards or preformed pipe insulation, it isadvisable to examine properties of interest in all three axes.6.4 Since soaking heat exposure seldom occurs under “asinstalled” conditions, and such exposure will produce resultsthat may be misleading, samples shall be conditioned us
30、inghot-face-/cold-face methods rather than soaking heat. Soakingheat exposure should be limited to preliminary evaluation andquality control testing.6.5 The elevated temperature exposure time required toeffect major change will vary with the generic type of productbeing tested. Preliminary trials sh
31、all be made to establish theminimum hot surface exposure time required for a particularinsulation material. The minimum exposure time has beenreached when the property of interest shows no more thanexpected random variations in three consecutive readings takenat three hour intervals.7. Test Specimen
32、s7.1 The test specimens shall be selected to be representativeof the material under evaluation. Original surfaces shall beretained at least on the hot face of the specimens.7.2 Other specimen dimensions shall conform to the re-quirements of Test Method C 411. Where further fabrication ofthe specimen
33、 after exposure is not practical, additional speci-mens, precut to the required size, shall be exposed separately.8. Procedure8.1 Hot Surface PerformanceTest and report the hotsurface performance of the insulation in accordance with TestMethod C 411 with the following exceptions and additions.8.1.1
34、The thickness of the test specimens shall be theintended thickness of the application or the manufacturersrecommended minimum and maximum thickness for the testtemperature. The number of layers of insulation exposed andtested shall be representative of the intended application or themanufacturers re
35、commendation at the test thickness.8.1.2 Unless a specific heat-up period is dictated by theintended application, included in the material specification orC447032recommended by the manufacturer, the apparatus shall bepreheated to the test temperature using a blank specimen ofsimilar thermal transmis
36、sion 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.8.1.3 The hot face temperature shall be the service tempera-ture being evaluated; 0,+5%.8.1.4 Where specific fastening methods are dictated by
37、thematerial specification, the insulation shall be held against thehot surface by means representing these fastening methods, forexample, screws, exterior frames, etc. The attachment methodshall be included in the report.8.1.5 Measure and report the dimensions and weight of thespecimens before and a
38、fter exposure. Suitable measuringinstruments and procedures can be found in Test MethodsC 167, C 303 or D 1622, and C 302 for blankets or felt, blockor board, and preformed pipe insulation respectively. Dimen-sions, and changes in dimensions, of the hot and cold facesshall be measured and reported s
39、eparately.8.1.6 Record the temperature rise during heat-up at 1-in.(25-mm) increments through the thickness of the specimen asan indication of endothermic or exothermic reactions withinthe insulation. Temperature shall be recorded continuously, orat a maximum interval of 5 min, until equilibrium is
40、reached.Suitable temperature sensors with a maximum response time of1 min and an accuracy of + / 1 % shall be used. The sensorsshall be located at the top center of the specimen for preformedpipe covering.8.2 Thermal Transmission PropertiesTest and report thethermal transmission properties of the in
41、sulation in accordancewith Test Methods C 177 and C 518 for blanket, felt, block orboard insulation or Test Method C 335 for preformed pipeinsulation.8.2.1 The test thickness shall be 112 612in. (38 6 13 mm)for Test Methods C 177 and C 518. For Test Method C 335 thetest thickness is adjusted as requ
42、ired to achieve the proper coldface temperature.8.2.2 The hot face temperature shall be the service tempera-ture being evaluated; 0,+5%.8.2.3 The cold face temperature shall be representative ofthe intended application or a maximum of 200F (93C).8.2.4 Prior to measurement the specimens shall be expo
43、sedon the test apparatus at the test temperature for the minimumperiod determined in 6.5. Separate hot surface exposure is notrequired.NOTE 2Where cyclic operating conditions are anticipated, it isprudent to confirm thermal transmission properties at lower temperaturesfollowing exposure to the maxim
44、um hot face temperature.8.3 Other PropertiesTest and report the other pertinentproperties of the insulation following hot surface exposure.8.3.1 Specimens shall be obtained from material exposed inaccordance with 7.1. Where further fabrication after exposureis not possible, additional specimens prec
45、ut to the required sizeare exposed separately maintaining the thickness and otherexposure parameters of 7.1.8.3.2 The full thickness of the exposed specimen shall betested. Where it is impractical to test the specimens at fullthickness, they may be carefully slit to two or more layers. Theresults of
46、 tests on each layer shall be reported separately andidentified as to the original location through the thickness fromhot to cold face.8.3.3 Where it is useful to compare the properties of theinsulation material before and after exposure, the specimensused for“ before exposure” tests shall be of the
47、 same size andselected from similar material as those used for the “afterexposure” test.8.3.4 Depending on the application, the following propertiesare useful in estimating the suitability of the insulation follow-ing exposure to the test service temperature. Additional perti-nent properties are fou
48、nd in the applicable material specifica-tion and the manufacturers literature. The provisions ofSection 5 shall be considered in selecting properties for testing.8.3.4.1 Compression PropertiesTest Method C 165 orTest Method D 1621.8.3.4.2 Flexural StrengthTest Methods C 203, TestMethod C 446.8.3.4.3
49、 Water/Moisture Absorption/Repellency/WickingAbilityRefer to the appropriate material specification.8.3.4.4 Tumbling FriabilityTest Method C 421.9. 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 determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.
