1、Designation: C 667 09Standard Specification forPrefabricated Reflective Insulation Systems for Equipmentand Pipe Operating at Temperatures above Ambient Air1This standard is issued under the fixed designation C 667; the number immediately following the designation indicates the year oforiginal adopt
2、ion or, in the case of revision, the year of last 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 specification covers the requirements for all metalprefabricated, re
3、flective insulation systems for equipment andpiping operating in air at temperatures above ambient. Typicalapplications are in nuclear power-generating plants and indus-trial plants.1.2 Reflective insulation is thermal insulation that reducesradiant heat transfer across spaces by the use of surfaces
4、 ofhigh reflectance and low emittance.1.3 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.4 This standard does not purport to address a
5、ll 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 applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C 168 Terminology R
6、elating to Thermal InsulationC 335 Test Method for Steady-State Heat Transfer Proper-ties of Pipe InsulationC411 Test Method for Hot-Surface Performance of High-Temperature Thermal InsulationC 835 Test Method for Total Hemispherical Emittance ofSurfaces up to 1400CC 854 Test for Resistance to Extern
7、al Loads on MetalReflective Pipe Insulation3C 1045 Practice for Calculating Thermal TransmissionProperties Under Steady-State ConditionsC 1058 Practice for Selecting Temperatures for Evaluatingand Reporting Thermal Properties of Thermal InsulationC 1061 Standard Guide for Prefabricated Panel Insulat
8、ionSystems for Ducts and Equipment Operating at Tempera-tures Above Ambient Air3C 1371 Test Method for Determination of Emittance ofMaterials Near Room Temperature Using Portable Emis-someters3. Terminology3.1 Definitions:3.1.1 Terms relating to thermal insulation materials andtesting are in accorda
9、nce with Terminology C 168.3.2 Definitions of Terms Specific to This Standard:3.2.1 convection stopsseals used to reduce convectionlosses.3.2.2 end supportsstructural members placed at the end ofa unit of insulation and fastened to both the inner and outercase.3.2.2.1 DiscussionThe primary purpose o
10、f the end sup-ports is to increase the structural integrity of the unit.3.2.3 inner casethe innermost sheet of the unit of insula-tion (closest to the hot surface).3.2.3.1 Discussion The inner case may perform structuralfunctions in addition to its thermal functions.3.2.4 insulation assemblyan assem
11、bly of insulation unitsarranged and secured together in a prescribed order thatcomprises the complete insulation for a vessel, pump, pipeline,or other component for a single design objective.3.2.5 insulation systema collection of insulation assem-blies, that when secured together in a prescribed ord
12、er, com-prises the complete insulation for a vessel, pump, pipeline, orother component for a single design objective.3.2.6 lap strapsstrips that overlap a longitudinal or cir-cumferential joint in the insulation which aligns adjacentinsulation units and may also serve to restrict air infiltrationand
13、 convection losses and to shed external falling water.3.2.6.1 DiscussionThe lap straps may be integral with onepiece of the outer case or separate strips secured to it.1This specification is under the jurisdiction of ASTM Committee C16 onThermal Insulation and is the direct responsibility of Subcomm
14、ittee C16.21 onReflective Insulation.Current edition approved April 15, 2009. Published May 2009. Originallyapproved in 1992. Last previous edition approved in 2001 as C 667-01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. F
15、or Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA
16、19428-2959, United States.3.2.7 outer casethe outermost sheet or the unit of insula-tion (farthest from the hot surface). It usually performsstructural functions in addition to its thermal functions.3.2.8 penetrationsopenings in a unit of insulation fromthe cold surface through to the hot surface.3.
17、2.9 reflective linersthose reflective sheets or foil inter-posed between the inner and outer case to reflect radiantenergy, to minimize emission of radiant energy, and to restrictinternal convection.3.2.10 thickness(see Fig. 1).3.2.11 unit of insulationa single structurally independentassembly of in
18、ner case, outer case, reflective liners, and endsupports (if required).4. Ordering Information4.1 Ordering information shall include the following:4.1.1 Service requirements including operating hot surfacetemperature, expected ambient temperatures, and ambient airvelocities,4.1.2 Expected service li
19、fe and any special environmentalexposures,4.1.3 Permitted average heat loss per unit of cold surface oras otherwise specified,4.1.4 Personnel exposure surface temperature limitations,4.1.5 Expected seismic, loading, and vibration exposures,4.1.6 Purchasers systems and equipment drawings,4.1.7 Limits
20、, if any, on size, maximum thickness, weight, ornumber of insulation units requiring removal for inspection,4.1.8 Location of components or maintenance, or both, andsystems requiring removal of units for inspections,4.1.9 Any unusual operating or test conditions, and4.1.10 Cleanliness level required
21、.5. Materials and Manufacture5.1 Each insulation unit is a rigid, self-contained, prefabri-cated metal construction comprised of an inner casing and anouter casing, and if needed, one or more reflective linerssupported and spaced so as to minimize internal convectionand conduction. These parts are a
22、rranged to form a durablerigid assembly with separated air spaces between the inner andouter casing and the individual reflective liners.5.2 The reflective insulation described herein is limited tosystems of insulating units, designed by the manufacturer to fitthe equipment or piping to be insulated
23、, and engineered for thepurchasers service requirements.5.3 All parts of reflective insulation units be made of metalsthat meet the thermal, physical, and chemical requirements notonly of the insulation as a unit, but also as an assembly of unitsforming the insulation system. The materials shall per
24、formtheir functions for the service life specified and be compatiblewith the environment in which they will be used.5.4 The stainless steel liners/foils shall be a minimum of0.002 in. (0.05 mm) in thickness. Liners shall have anemittance of 0.25 or less when tested at 75 F (24 C) inFIG. 1 Illustrati
25、on of Terms Relating to Prefabricated Reflective Insulation SystemsC667092accordance with Test Method C 1371. There shall be a mini-mum of three foils per in. of insulation thickness. The optionsfor the foils configuration are flat or patterned.6. Temperature Limitations6.1 Each insulation unit must
26、 effectively limit the flow ofheat through the insulation by radiation, convection, andconduction. The reflective liners (also referred to as radiationshields or foils) are made of metals having low emittance andhigh reflectance. The emittance shall be tested in accordancewith Test Method C 835 or C
27、 1371. The number and spacing ofthe liners are determined by the required limitation of heatflow.6.2 The temperature limits of various materials shall bebased on the potential increase in radiant heat transfer acrossspaces due to a reduction in reflectance and a correspondingincrease in emittance re
28、sulting from surface oxidation. Indi-vidual components of the insulation system operating attemperatures of 750F (400C) or higher shall not be made ofaluminum or aluminum alloys. Components operating at1200F (649C) or higher, shall be manufactured from Type300 series austenitic stainless steel or ma
29、terial with the sameproperties.6.3 A representative unit or assembly shall be tested inaccordance with Test Method C411.7. Thermal Performance7.1 The purchase specification shall clearly indicate thepermissible average rate of heat loss per unit area for each typeof surface. The tests shall be in ac
30、cordance with Test MethodC 335 for pipes, or Test Method C 1061 for flat surfaces, or atest method agreed upon between the purchaser and manufac-turer. Table 1 and Table 2 contain maximum values forapparent thermal conductivity. Butt joint heat losses shall beaccounted for by including at least one
31、butt joint within themetered area in thermal performance test. Practices C 1045 andC 1058 shall be used for determining and reporting thermaltransmission properties.7.2 Due to the limitation of present configurations of reflec-tive insulation, those being flat, cone and cylindrical, there canbe a si
32、gnificant difference between the hot equipment surfacearea and the outer case area. Therefore, the thermal perfor-mance for equipment be referenced to the area of the outercase, unless otherwise specified. To be consistent, the outercase area shall also be used for pipe, unless otherwise specified.7
33、.3 Thermal performance of pipe insulation per unit of coldsurface area shall be obtained by multiplying transference (T)or conductance (C) as determined by Test Methods C 335,byratio of the radii of the insulation outer surface (r2) and the testpipe (ro). Example:Cc 5 C 3 ro/r2(1)where:Cc = conducta
34、nce based on the area of the insulation (coldsurface).7.4 Heat loss shall include consideration of insulation ori-entation (horizontal or vertical) and the insulation joint design.7.5 The specification not limit both heat loss throughinsulation and outer case temperature at the same time. Ifpersonne
35、l exposure to high surface temperatures is consideredto be a danger in limited areas, those areas shall be explicitlyidentified with the maximum allowable surface temperatureand the ambient design conditions, and one or more of thefollowing alternatives shall be used.7.5.1 External guarding,7.5.2 Ad
36、ditional insulation,7.5.3 High emittance outer case, or7.5.4 Other acceptable techniques agreed upon between thepurchaser and the supplier.7.6 Increased heat loss associated with modified insulationor reduced insulation thickness shall be identified.8. Design and Construction8.1 The insulation shall
37、 be metal construction and shallform a system of prefabricated insulation units in integratedassemblies designed to fit the surfaces to be insulated withallowance for thermal expansion and contraction.8.2 Insulation shall be designed to fit the specified surface,being insulated as necessary to limit
38、 heat losses due toconvection and conduction. Insulation shall be manufacturedso that edges or projections do not cause damage to the surfaceof the insulated pipe or equipment.8.3 Insulation units shall have end (or edge) supports andconvection stops at intervals as required to limit convectiveheat
39、loss. Insulation units shall have banded and sealed ends,lapped or stepped ends, or a purchaser approved design thatminimizes heat leakage at joints. Gaps required for thermalexpansion or for internal unit construction are permitted whenapproved by the purchaser.8.4 Insulation units and assemblies s
40、hall have the strengthand rigidity to withstand specified seismic forces, and theoperational loading and vibration requirements. Each unit shallhave strength and rigidity to hold its internal parts in its spacialTABLE 1 PanelsApparent Thermal ConductivityAMean Temperature Btu in./h ft2(W/mk)184 (84.
41、4) 0.369 (0.053)291 (143.8) 0.477 (0.069)398 (203.3) 0.657 (0.095)AThe thermal transmission properties of metal reflective insulation depends ontemperature, temperature difference, dimensions, emittance, and heat flow direc-tion. The apparent thermal conductivity requirements specified in the table
42、arebased on specimens tested as specified in 7.1.TABLE 2 PipingApparent Thermal ConductivityATmean F TmeanC k k (W/mk)Horizontal 181 82 0.506 0.073Horizontal 292 145 0.599 0.087Horizontal 411 211 0.741 0.107Vertical 181 83 0.625 0.091Vertical 294 146 0.755 0.109Vertical 416 213 0.886 0.128AThe therm
43、al transmission properties of metal reflective insulation depends ontemperature, temperature difference, dimensions, emittance, and heat flow direc-tion. The apparent thermal conductivity requirements specified in the table arebased on specimens tested as specified in 7.1.C667093relationship without
44、 bunching or matting. Resistance to exter-nal loads shall be determined by the use of Test Method C 854.8.5 Insulation units and assemblies shall have provisions toretard entrance of liquids and to drain condensate, moisture, orother liquids from spill or other exposures specified in theordering inf
45、ormation.8.6 Units shall have provisions to prevent internal pressurebuild-up.8.7 Attachments, fasteners, and interlocking constructionshall hold the insulation units firmly in place in the assembliesunder all specified operating and test conditions. Locations ofsuch items on interchangeable insulat
46、ion units shall bematched.8.8 Provisions shall be included for mating insulation tobranch piping insulation at valves, pumps, and noncylindricalsections for penetrations through the insulation for instrumen-tation or other purposes.9. Installation and Removal9.1 Individual or groups of removable ins
47、ulation units shallbe provided for examination of component surfaces at loca-tions shown on purchasers drawings, or as otherwise specifiedor agreed upon between the purchaser and supplier. Insulationassembly design shall permit removal of such units with aminimum of disturbance to adjacent insulatio
48、n units.9.2 Insulation units shall be installed either individually orin groups so as to be able to perform replacement, mainte-nance, examination, and repairs of the insulated componentswith minimum disturbance of large portions of the insulationsystem. Limits on size of groups or number of units s
49、hall be asspecified by the purchaser.9.3 The insulation shall permit removal and reinstallationmanually without the use of special tools unless otherwisespecified by the purchaser.9.4 The maximum weight of each individual insulation unitor combination units attached together during removal andreinstallation shall be as specified by the purchaser.10. Cleaning10.1 Materials shall be kept visibly free of oil, grease, andother dirt during all fabricating operations.10.2 All materials components shall be cleaned to anacceptable level as agreed upon between the pu
