ASTM E970-2008 431 Standard Test Method for Critical Radiant Flux of Exposed Attic Floor Insulation Using a Radiant Heat Energy Source.pdf

1、Designation: E 970 08An American National StandardStandard Test Method forCritical Radiant Flux of Exposed Attic Floor Insulation Usinga Radiant Heat Energy Source1This standard is issued under the fixed designation E 970; the number immediately following the designation indicates the year oforigina

2、l adoption 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 fire-test-response standard describes a procedurefor measurin

3、g the critical radiant flux of exposed attic floorinsulation subjected to a flaming ignition source in a gradedradiant heat energy environment in a test chamber. Thespecimen is any attic floor insulation. This test method is notapplicable to those insulations that melt or shrink away whenexposed to

4、the radiant heat energy environment or the pilotburner.1.2 This fire-test-response standard measures the criticalradiant flux at the point at which the flame advances thefarthest. It provides a basis for estimating one aspect of fireexposure behavior for exposed attic floor insulation. Theimposed ra

5、diant flux simulates the thermal radiation levelslikely to impinge on the floors of attics whose upper surfacesare heated by the sun through the roof or by flames from anincidental fire in the attic. This fire-test-response standard wasdeveloped to simulate an important fire exposure component offir

6、es that develop in attics, but is not intended for use inestimating flame spread behavior of insulation installed otherthan on the attic floor.1.3 The values stated in SI units are to be regarded asstandard. The values given in parentheses are for informationonly.1.4 The text of this standard refere

7、nces notes and footnotesthat provide explanatory information. These notes and foot-notes, excluding those in tables and figures, shall not beconsidered as requirements of this standard.1.5 This standard is used to measure and describe theresponse of materials, products, or assemblies to heat andflam

8、e under controlled conditions, but does not by itselfincorporate all factors required for fire hazard or fire riskassessment of the materials, products, or assemblies underactual fire conditions.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use.

9、 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.1.7 The text of this standard references notes and footnoteswhich provide explanatory material. These notes and footnote

10、s(excluding those in tables and figures) shall not be consideredas requirements of the standard.2. Referenced Documents2.1 ASTM Standards:2C 665 Specification for Mineral-Fiber Blanket Thermal In-sulation for Light Frame Construction and ManufacturedHousingC 764 Specification for Mineral Fiber Loose

11、-Fill ThermalInsulationE84 Test Method for Surface Burning Characteristics ofBuilding MaterialsE 122 Practice for Calculating Sample Size to Estimate,With Specified Precision, the Average for a Characteristicof a Lot or ProcessE 176 Terminology of Fire StandardsE 631 Terminology of Building Construc

12、tionsE 648 Test Method for Critical Radiant Flux of Floor-Covering Systems Using a Radiant Heat Energy Source2.2 Federal Specifications:HH-I-515 Insulation Thermal (Loose Fill for Pneumatic orPoured Application), Cellulosic or Wood Fiber3HH-I-521, Insulation Blankets, Thermal (Mineral Fiber, forAmbi

13、ent Temperature)3HH-I-1030 Insulation, Thermal (Mineral Fiber, for Pneu-matic or Poured Application)33. Terminology3.1 For definitions of terms used in this test method andassociated with fire issues refer to the terminology contained inTerminology E 176.3.2 Definition:1This test method is under the

14、 jurisdiction of ASTM Committee E05 on FireStandards and is the direct responsibility of Subcommittee E05.22 on SurfaceBurning.Current edition approved Oct. 1, 2008. Published November 2008. Originallyapproved in 1983. Last previous edition approved in 2007 as E 970 07.2For referenced ASTM standards

15、, 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 page onthe ASTM website.3Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbin

16、s Ave., Philadelphia, PA 19111-5098, http:/www.dodssp.daps.mil.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.1 attic, nan accessible enclosed space in a buildingimmediately below the roof and wholly or partly within theroof fra

17、ming.3.2.2 See Terminology E 631 for additional definitions ofterms used in this test method.3.3 Definitions of Terms Specific to This Standard:3.3.1 critical radiant flux, nthe level of incident radiantheat energy on the attic floor insulation system at the mostdistant flame-out point. It is report

18、ed as W/cm2(or Btu/ft2s).3.3.2 radiant flux profile, nthe graph relating incidentradiant heat energy on the specimen plane to distance from thepoint of initiation of flaming ignition, that is, 0 mm.3.3.3 total flux metre, nthe instrument used to measure thelevel of radiant heat energy incident on th

19、e specimen plane atany point.4. Summary of Test Method4.1 A horizontally mounted insulation specimen is exposedto the heat from an air-gas radiant heat energy panel locatedabove and inclined at 30 6 5 to the specimen. After a shortpreheat, the hottest end of the specimen is ignited with a smallcalib

20、rated flame. The distance to the farthest advance offlaming is measured, converted to kilowatts per square meterfrom a previously prepared radiant flux profile graph, andreported as the critical radiant flux.5. Significance and Use5.1 This fire-test-response standard is designed to provide abasis fo

21、r estimating one aspect of the fire exposure behavior toexposed insulation installed on the floors of building attics. Thetest environment is intended to simulate conditions that havebeen observed and defined in full-scale attic experiments.5.2 The test is intended to be suitable for regulatory stat

22、utes,specification acceptance, design purposes, or development andresearch.5.3 The fundamental assumption inherent in the test is thatcritical radiant flux is one measure of the surface burningcharacteristics of exposed insulation on floors or between joistsof attics.5.4 The test is applicable to at

23、tic floor insulation specimensthat follow or simulate accepted installation practice.5.5 In this procedure, the specimens are subjected to one ormore specific sets of laboratory fire test exposure conditions. Ifdifferent test conditions are substituted or the anticipatedend-use conditions are change

24、d, caution should be used topredict changes in the performance characteristics measured byor from this test. Therefore, the results are strictly valid onlyfor the fire test exposure conditions described in this procedure.5.5.1 If the test results obtained by this test method are to beconsidered in t

25、he total assessment of fire hazard in a buildingstructure, then all pertinent established criteria for fire hazardassessment developed by Committee E-5 must be included inthe consideration.6. Apparatus6.1 The apparatus shall be as shown in Fig. 1, located in adraft-protected laboratory that maintain

26、s a temperature from10.0 to 26.7C (50 to 80F) and a relative humidity from 30 to70 %:6.1.1 The radiant panel test chamber (Fig. 1 and Fig. 2) shallconsist of an enclosure 1400 mm (55 in.) long by 500 mm(1912 in.) deep by 710 mm (28 in.) above the test specimen.The sides, ends, and top shall be of 13

27、-mm (12-in.) calciumsilicate, 740-kg/m3(46-lb/ft3) nominal density, insulating ma-terial with a thermal conductivity at 177C (350F) of 0.128W/(mK) (0.89 Btu in./(hft2F). One side shall be providedNOTE 1All dimensions in millimetres. 1 in. = 25.4 mm.FIG. 1 Flooring Radiant Tester Schematic, Side Elev

28、ationNOTE 1All dimensions in millimetres. 1 in. = 25.4 mm.FIG. 2 Flooring Radiant Panel Tester Schematic Low Flux End,ElevationE970082with an approximately 100 by 1100 mm (4 by 44 in.) draft-tightfire-resistant glass window so that the entire length of the testspecimen is visible from outside the fi

29、re test chamber. On thesame side and below the observation window is a door which,when open, allows the specimen platform to be moved out formounting or removal of test specimens. At the low flux end ofthe chamber on the 500 mm side, a draft-tight fire-resistantwindow is permitted for additional obs

30、ervations.6.1.2 The bottom of the test chamber shall consist of asliding steel platform which has provisions for rigidly securingthe test specimen holder in fixed and level position. The free,or air access, area around the platform shall be in the rangefrom 0.2580 to 0.3225 m2(400 to 500 in.2).6.1.3

31、 When the flame front advance is to be measured, ametal scale marked with 10 mm intervals shall be installed onthe back of the platform or on the back wall of the chamber.6.1.4 The top of the chamber shall have an exhaust stackwith interior dimensions of 102 6 3mm(46 0.13 in.) wideby 380 6 3 mm (15.

32、00 6 0.13 in.) deep by 318 6 3mm(12.506 0.13 in.) high at the opposite end of the chamber fromthe radiant energy source.6.2 Radiant Heat Energy Source, a panel of porous materialmounted in a cast iron or steel frame, with a radiation surfaceof 305 by 457 mm (12 by 18 in.). It shall be capable ofoper

33、ating at temperatures up to 816C (1500F). The panel fuelsystem shall consist of a venturi-type aspirator for mixing gas4and air at approximately atmospheric pressure, a clean dry airsupply capable of providing 28.3 m3/h (1000 f3t/h) at standardtemperature and pressure at 76 mm (3.0 in.) of water, an

34、dsuitable instrumentation for monitoring and controlling theflow of fuel to the panel.6.2.1 The radiant heat energy panel is mounted in thechamber at 30 6 5 to the horizontal specimen plane. Theradiant energy panel angle shall be adjusted to obtain the fluxprofile within the limits specified in acco

35、rdance with 10.6. Thehorizontal distance from the 0 mark on the specimen fixture tothe bottom edge (projected) of the radiating surface of thepanel is 89 6 3 mm (3.5 6 0.13 in.). The panel-to-specimenvertical distance is 140 6 3 mm (5.5 6 0.13 in.) (Fig. 1).6.2.2 Radiation Pyrometer for standardizin

36、g the thermaloutput of the panel, suitable for viewing a circular area 254 mm(10 in.) in diameter at a range of about 1.37 m (54 in.). It shallbe calibrated over the 460 to 510C (860 to 950F) operatingblackbody temperature range in accordance with the proceduredescribed in Annex A1.6.2.3 Voltmeter,

37、high-impedance or potentiometric, with asuitable millivolt range shall be used to monitor the output ofthe radiation pyrometer described in 6.2.2.6.3 Dummy Specimen Holder (Fig. 3 and Fig. 4), con-structed from heat-resistant stainless steel (UNS N08330 (AISIType 330) or equivalent) having a thickne

38、ss of 1.98 mm (0.078in.) and an overall dimension of 1140 by 320 mm (45 by 1234in.) with a specimen opening of 200 by 1000 mm (7.9 by 39.4in.). Six slots shall be cut in the flange on either side of theholder to reduce warping. The holder shall be fastened to theplatform with two stud bolts at each

39、end.6.4 Dummy Specimen, used in the flux profile determina-tion, made of 19-mm (34-in.) inorganic 740-kg/m3(46-lb/ft3)nominal density calcium silicate board (Fig. 3 and Fig. 4). It is250 mm (10 in.) wide by 1070 mm (42 in.) long with 27-mm(1116-in.) diameter holes centered on and along the centerlin

40、e4Gas used in this test method shall be either commercial grade propane havinga heating value of approximately 83.1 MJ/m3(2500 Btu/ft3), or natural gas, orcommercial grade methane having a minimum purity of 96 %.NOTE 1All dimensions in millimetres. 1 in. = 25.4 mm.FIG. 3 Zero Reference Point Related

41、 to Detecting PlaneNOTE 1All dimensions in millimetres. 1 in. = 25.4 mm.FIG. 4 Dummy Specimen in Specimen HolderE970083at the 100, 200, 300, .,900, and 980-mm locations measuredfrom the maximum flux end of the specimen.6.4.1 To provide proper and consistent seating of the fluxmeter in the hole openi

42、ngs, a stainless steel or galvanized steelbearing plate (Fig. 3 and Fig. 4) shall be mounted and firmlysecured to the underside of the calcium silicate board withholes corresponding to those specified above. The bearing plateshall run the length of the dummy specimen board and have awidth of 76 mm (

43、3.0 in.). The thickness of the bearing plateshall be set in order to maintain the flux meter height specifiedin 10.5. The maximum thickness of the bearing plate shall notexceed 3 mm (18 in.).6.5 Total Heat Flux Transducer, to determine the fluxprofile of the chamber in conjunction with the dummy spe

44、ci-men (Fig. 3), shall be of the Schmidt-Boelter5type, have arange from 0 to 15 kW/m2(0 to 1.32 Btu/ft2s) and shall becalibrated over the operating flux level range from 0.10 to 15kW/m2in accordance with the procedure outlined in AnnexA1. A source of 15 to 25C cooling water shall be provided forthis

45、 instrument.6.5.1 Voltmeter, high-impedance or potentiometric, with arange from 0 to 10 mV and reading to 0.01 mV shall be usedto measure the output of the total heat flux transducer duringthe flux profile determination.6.6 Specimen Tray (Fig. 5), constructed from 14-gageheat-resistant stainless ste

46、el (UNS-N08330 (AISI Type 330) orequivalent), thickness 1.98 mm (0.078 in.). The depth of thetray is 50 mm (2 in.). The flanges of the specimen tray aredrilled to accommodate two stud bolts at each end; the bottomsurface of the flange is 21 mm (0.83 in.) below the top edge ofthe specimen tray. The o

47、verall dimensions of the tray and thewidth of the flanges shall be such that the tray fills the openspace in the sliding platform. The tray must be adequate tocontain a specimen at least 1000 mm (40 in.) long and 250 mm(10 in.) wide. The zero reference point on the dummy specimenshall coincide with

48、the pilot burner flame impingement point(Fig. 3).6.7 Pilot Burner, used to ignite the specimen, is a nominal6mm(14 in.) inside diameter, 10 mm (38 in.) outside diameterstainless steel tube line burner having 19 evenly spaced 0.7 mm(0.028 in.) diameter (No. 70 drill) holes drilled radially alongthe c

49、enterline and 16 evenly spaced 0.7 mm (0.028 in.)diameter (No. 70 drill) holes drilled radially 60 below thecenterline (Fig. 6).6.7.1 In operation, the gas4flow is adjusted to 0.85 to 0.115m2/h (3.0 to 4.0 SCFH) (air scale) flow rate. With the gas flowproperly adjusted and the pilot burner in the test position, thepilot flame will extend from approximately 63.5 mm (2.5 in.)at the ends to approximately 127 mm (5 in.) at the center.6.7.2 The holes in the pilot burner shall be kept clean. Onemeans for opening the holes in the pilot burner is to usen