[Code of Federal Regulations]
[Title 16, Volume 2]
[Revised as of January 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 16CFR1209.6]
[Page 288-292]
TITLE 16--COMMERCIAL PRACTICES
CHAPTER II--CONSUMER PRODUCT SAFETY COMMISSION
PART 1209--INTERIM SAFETY STANDARD FOR CELLULOSE INSULATION--Table of Contents
Subpart A--The Standard
Sec. 1209.6 Test procedures for critical radiant flux.
This section provides the test procedure for determining the
critical radiant flux of exposed attic floor insulation using a radiant
heat energy source.
(a) Apparatus and description of test procedure. Test chamber
(Figures 3 and 4 paragraph (b) of this section). An air-gas fueled
radiant heat energy panel or equivalent panel inclined at 30 deg. above
and directed at a horizontally-mounted attic floor insulation specimen.
The radiant panel generates a radiant energy flux distribution ranging
along the approximately 100-cm length of the test specimen from a
nominal maximum of 1.0 W/cm.\2\ to a minimum of 0.1 W/cm\2\. The test is
initiated by open flame ignition from a pilot burner. The distance
burned to flame-out is converted to W/cm\2\ from the flux profile graph
(Figure 8) and reported as critical radiant flux, W/cm\2\. Section
1209.8 provides a procedure for calibrating the radiation pyrometer used
to standardize the thermal output of the panel.
(b) Construction and instrumentation of the radiant panel test
chamber. The radiant panel test chamber shall be constructed and
instrumented as follows:
(1) The radiant panel test chamber employed for this test shall be
located in a draft protected area maintained at 213 deg.C
(69.89 deg.F) and relative humidity of 5020%.
The radiant panel test chamber, (Figures 3 and 4) shall consist of an
enclosure 140 cm (55 in) long by 50 cm (19\1/2\ in) deep by 71 cm (28
in) above the test specimen. The sides, ends, and top shall be of 1.3 cm
nominal (\1/2\ in) calcium silicate board, such as Marinite I, 0.74 g/
cm\3\ (46 lb/ft\3\) nominal density, with a thermal conductivity at 177
deg.C (350 deg.F) of 1.11 cal (g)/hr cm\2\ deg.C/cm [0.89 Btu/(hr)
(ft\2\) ( deg.F/in)]. One side shall be provided with an approximately
10 cm x 110 cm (4 x 44 inches) draft tight fire resistant glass window
so that the entire length of the test specimen may be observed from
ourside the fire test chamber. On the same side and below the
observation window is a door which, when open, allows the specimen
platform to be moved out for mounting or removal of test specimens. A
draft tight, fire resistant observation window may be installed at the
low flux end of the chamber.
(2) The bottom of the test chamber shall consist of a sliding steel
platform which has provisions for rigidly securing the test specimen
holder in a fixed and level position. The free, or air access, area
around the platform shall be
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in the range of 1935-3225 cm\2\ (300-500 square in). The top of the
chamber shall have an exhaust stack with interior dimensions of 10.2 cm
(4 in) wide by 38 cm (15 in) deep by 31.8 cm (12.5 in) high at the
opposite end of the chamber from the radiant energy source. The radiant
heat energy source shall be a panel of porous refractory material
mounted in a cast iron frame, with a radiation surface of 30.5x45.7 cm
nominal (12 by 18 in). The panel fuel system shall consist of a venturi-
type aspirator or equivalent system for mixing gas and air at
approximately atmospheric pressure, a clean dry air supply capable of
providing 28.3 NTP (Normal Temperature and Pressure m\3\ per hr (1000
standard cubic feet per hour) at 7.6 cm (3.0 in) of water, and suitable
instrumentation for monitoring and controlling the flow of fuel to the
panel.
(3) The radiant heat energy panel shall be mounted in the chamber
300.5 deg. to the horizontal specimen plane. The horizontal
distance from the 0 mark on the specimen fixture to the bottom edge
(projected) of the radiating surface of the panel is 8.9
cm0.1 (3\1/2\\1/32\ in). The panel to specimen
vertical distance is 14.0 cm0.1 (5\1/2\\1/32\
in) (see Figure 5). The angle and dimensions given above are critical in
order to obtain the required radiant flux. The radiation pyrometer for
standardizing the thermal output of the panel shall be suitable for
viewing a circular area 25.0 cm (10 in) in diameter at a range of about
1.37 m (54 in). It shall be calibrated over the black body temperature
range of 490-510 deg.C (914-950 deg.F) in accordance with the
procedure described in Sec. 1209.8. A high impedance voltmeter with a
suitable millivolt range shall be used to monitor the output of the
radiation pyrometer described. The dummy holder (see Figure 6), shall be
constructed from 14 gauge heat-resistant stainless steel (AISI Type 300
(UNA-N08330)) or equivalent thickness 0.198 cm (0.078 in), having
overall dimension of 114 cm (45 in) by 32 cm (12\3/4\ in) with a
specimen opening of 20 cm (7.9 inches) by 100 cm (39.4 in). Six slots
are cut in the flange on either side of the holder to reduce warping.
The holder is fastened to the platform with two stud bolts at each end.
(4) The specimen tray (see Figure 7) shall be constructed from 14
gauge heat-resistant stainless steel (AISI Type 300 (UNA-N08330)) or
equivalent, thickness 0.198 cm (0.078 in). The depth of the tray is
5.00.2 cm (2\5/64\ in). The flanges of the
specimen tray are drilled to accommodate two stud bolts at each end; the
bottom surface of the flange is 2.10.1 cm
(0.830.04 in) below the top edge of the specimen tray. The
overall dimensions of the tray and the width of the flanges are not
critical and should be chosen so that the tray essentially fills the
open space in the sliding platform. Tray must be adequate to contain a
specimen at least 100 cm long and 25 cm wide. It is important to note
that the zero reference point on the dummy specimen coincides with the
pilot burner flame impingement point (see Figure 5).
(5) The pilot burner used to ignite the specimen shall be a propane
venturi torch with an axially sysmmetric burner tip having a propane
supply tube with an orifice diameter of 0.00760.0013 cm
(0.0030.0005 in). In operation, the propane flow is adjusted
to give a pencil flame blue inner cone length of 1.3 cm (\1/2\ in). The
pilot burner is positioned so that the flame generated will impinge on
the centerline of the specimen at the zero reference point and at right
angles to the specimen length (see Figures 3 and 4). The burner shall be
capable of being swung out of the ignition position so that the flame is
horizontal and at least 5 cm (2 in) above the specimen plane.
(6) Two 3.2 mm nominal (\1/8\ in) diameter stainless steel sheathed,
grounded junction chromel alumel thermocouples are located in the
flooring radiant panel test chamber (see Figures 3 and 4). Thermocouples
shall be kept clean to ensure accuracy of readout. The chamber
thermocouple is located in the longitudinal central vertical plane of
the chamber 2.5 cm0.1 (1\1/32\ in) down from the
top and 10.2 cm0.1 (4 in\1/32\) back from the
inside of the exhaust stack. The exhaust stack thermocouple is centrally
located 15.20.1 cm (6\1/32\ in) from the top. A
temperature indicating device with a range of 100-500 deg.C (212-932
deg.F) may be used to determine the chamber temperatures prior to a
test.
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(7) An exhaust duct with a capacity of 28.3-85 NTP m\3\ per minute
(1000-3000 standard cubic feet per minute) decoupled from the chamber
stack by at least 7.6 cm (3 in) on all sides and with an effective area
of the canopy slightly larger than the plane area of the chamber with
the specimen platform in the out position shall be used to remove
combustion products from the chamber. With the panel turned on and dummy
specimen in place, there shall be no measurable difference in air flow
through the chamber stack with the exhaust on or off.
(8) The dummy specimen which is used in the flux profile
determination shall be made of 1.90.1 cm (\3/
4\\1/32\ in) 0.74 g/cm\3\ (46 lb/ft\3\) nominal density
calcium silicate board, such as Marinite I (see Figure 6). It is 25 cm
(10 in) wide by 107 cm (42 in) long with 2.70.1 cm (1\1/
16\\1/32\ in) diameter holes centered on and along the
centerline at the 10, 20, 30, 40, 50, 60, 70, 80, 90 cm locations
(within 0.1 cm), measured from the zero reference point at
the maximum flux end of the specimen. The total heat flux transducer
used to determine the flux profile of the chamber in conjunction with
the dummy specimen should be of the Schmidt-Boelter type, having a range
of 0-1.5 W/cm\2\ (0-1.32 Btu/ft\2\ s), and shall be calibrated over the
operating flux level range of .10 to 1.5 W/cm\2\ in accordance with the
procedure outlined in Sec. 1209.8. The incoming cooling water flowing
through the instrument shall be 15-25 deg.C (59-77 deg.F). A high
impedance voltmeter with a resolution of at least 0.01 mV shall be used
to measure the output of the total heat flux transducer during the flux
profile determination. A timer shall be used for measuring preheat and
pilot contact time.
(c) Safety procedures. The possibility of a gas-air fuel explosion
in the test chamber should be recognized. Suitable safeguards consistent
with sound engineering practice should be installed in the panel fuel
supply system. These may include one or more of the following:
(1) A gas feed cut-off activated when the air supply fails,
(2) A fire sensor directed at the panel surface that stops fuel flow
when the panel flame goes out,
(3) A commercial gas water heater or gas-fired furnace pilot burner
control thermostatic shut-off, which is activated when the gas supply
fails, or other suitable and approved device.
Manual reset is considered a desirable feature of any safeguard system
used. In view of the potential hazard from products of combustion, the
exhaust system must be so designed and operated that the laboratory
environment is protected from smoke and gas. The operator should be
instructed to minimize exposure to combustion products by following
sound safety practices, such as ensuring that the exhaust system is
working properly and wearing appropriate clothing, including gloves.
(d) Test specimens--(1) Specimens of insulation intended for
pneumatic applications. (i) Insulation shall be installed into the
specimen tray using the blower/cyclone apparatus described in
Sec. 1209.4(a).
(ii) Insulation shall be conditioned as described in Sec. 1209.4(b).
(iii) Apparatus 4, 6, 7, 8, 9 and 10 shall be used as
described in Sec. 1209.4(d)(1)(i) with the following additional
requirements.
(iv) The fill chamber (apparatus 6) shall be equipped with
openings in the front and back so that a radiant panel specimen tray can
be slid through the fill chamber.
(v) Adjust the blower control(s) (apparatus 9) such that
the supply and overflow blowers will operate at a no load voltage of 40
volts RMS.
(vi) Turn on the blowers simultaneously and proceed to fill the fill
chamber by picking up material from the box using the supply source
hose. Large clumps of insulation shall be broken by hand before feeding
them into the hose. Continue filling the chamber until large amounts of
insulation are being drawn into the overflow hose.
(vii) Slowly slide the specimen tray through the fill chamber so
that the low flux end of the tray is parallel with the back of the fill
chamber filling the tray by sliding the tray forward to allow an excess
of insulation to build up in the tray.
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(viii) Shut off the blowers and remove the specimen tray and gently
screed the insulation so that the insulation is level across the top of
the tray. Take care not to compact the insulation or to leave large
voids in the material. The tray may now be inserted into the radiant
panel.
(2) Specimens of insulation intended for pouring applications.
Insulation intended for pouring applications shall be poured into the
tray until the tray is overfilled and then carefully screeded to the top
of the the tray taking care not to compact the insulation or leave large
voids in the surface of the material.
(3) Specimens of insulation intended for pouring and pneumatic
applications. If the insulation is intended for both pouring and
pneumatic applications, or if it is uncertain whether the insulation
will be poured or blown, the insulation shall be tested using the test
procedures at paragraphs (d) (1) and (2) of this section for each of the
applications. Three specimens shall be tested under the test procedure
for each application. All of the specimens shall meet the criteria at
Sec. 1209.3(b) for passing the attic floor radiant panel test.
(e) Radiant heat energy flux profile standardization. In a
continuing program of tests, determine the flux profile at least once a
week. Where the time interval between tests is greater than one week,
determine the flux profile at the start of the test series.
(1) Mount the dummy specimen in the mounting frame and attach the
assembly to the sliding platform. With the sliding platform out of the
chamber, ignite the radiant panel. Allow the unit to heat for 1 hour.
The pilot burner is off during this determination. Adjust the fuel
mixture to give an air-rich flame. Make fuel flow settings to bring the
panel to an apparent black body temperature as measured by the radiation
pyrometer, of approximately 500 deg.C (932 deg.F), and bring the
chamber to a temperature of approximately 180 deg.C (356 deg.F). When
equilibrium has been established, move the specimen platform into the
chamber. Allow 0.5 hour for the closed chamber to reach equilibrium.
(2) Measure the radiant heat energy flux level at the 40 cm point
with the total flux meter instrumentation. This is done by inserting the
flux meter in the opening so that its detecting plane is 0.16-0.32 cm
(\1/16\-\1/8\ inch) above and parallel to the plane of the dummy
specimen and reading its output after 3010 seconds. If the
level is within the limits specified, the flux profile determination is
started. If it is not, make the necessary adjustments in the panel fuel
flow. A suggested flux profile data log format is shown in Figure 9.
(3) The test shall be run under chamber operating conditions which
give a flux profile as shown in Figure 8. The radiant heat energy
incident on the dummy specimen shall be between 0.87 and .95 W/cm\2\
(0.77 and .83 Btu/ft\2\ sec) at the 20 cm point, between 0.48 and 0.52
W/cm\2\ (0.42 and 0.46 Btu/ft\2\ sec) at the 40 cm point, and between
0.22 and 0.26 W/cm\2\ (0.19 and 0.23 Btu/ft\2\ sec) at the 60 cm point.
Insert the flux meter in the 10 cm opening, following the procedure
given above. Read the millivolt output at 3010 seconds and
proceed to the 20 cm point. Repeat the 10 cm procedure. The 30 to 90 cm
flux levels are determined in the same manner. Following the 90 cm
measurement, make a check reading at 40 cm. If this is within the limits
set forth, the test chamber is in calibration, and the profile
determination is completed. If not, carefully adjust fuel flow, allow
0.5 hour for equilibrium and repeat the procedure. Plot the radiant heat
energy flux data as a function of distance along the specimen plane on
rectangular coordinate graph paper. Carefully draw the best smooth curve
through the data points. This curve will hereafter be referred to as the
flux profile curve.
(4) Determine the open chamber apparent black body and chamber
temperatures that are identified with the standard flux profile by
opening the door and moving the specimen platform out. Allow 0.5 hour
for the chamber to reach equilibrium. Read the radiation pyrometer
output and record the apparent black body temperature. This is the
temperature setting that can be used in subsequent test work in lieu of
measuring the radiant flux at 20 cm, 40 cm, and 60 cm using the dummy
specimen. The chamber temperature also shall be determined again after
0.5
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hour and is an added check on operating conditions.
(f) Conditioning. Test specimens shall be conditioned to equilibrium
at 213 deg.C (69.85.4 deg.F) and a relative
humidity of 505 percent immediately prior to testing. A less
than 1% change in net weight of the specimen in two consecutive
weighings with two hours between each weighing constitutes equilibrium.
The maximum cumulative time a conditioned sample may be exposed to
conditions different from 213 deg.C (69.85.4
deg.F) and relative humidity of 505% before insertion in to
the radiant panel chamber for testing is 10 minutes.
(g) Test Procedure. (1) With the sliding platform out of the
chamber, ignite the radiant panel. Allow the unit to heat for 1 hour. It
is recommended that a sheet of inorganic millboard be used to cover the
opening when the hinged portion of the front panel is open and the
specimen platform is moved out of the chamber. The millboard is used to
prevent heating of the specimen and to protect the operator. Read the
panel apparent black body temperature and the chamber temperature. When
these temperatures are in agreement to within 5 deg.C
(9 deg.F) with those determined previously, during the flux
profile standardization procedure, the chamber is ready for use.
(2) Mount the specimen tray with insulation on the sliding platform
and position with stud bolts (see Figure 9). Ignite the pilot burner,
move the specimen into the chamber, and close the door. Start the timer.
After 2 minutes 5 seconds preheat, with the pilot burner on
and set so that the flame is horizontal and about 5 cm above the
specimen, bring the pilot burner flame into contact with the center of
the specimen at the 0 mark. Leave the pilot burner flame in contact with
the specimen for 2 minutes 5 seconds, or until all flaming
other than in the area of the pilot burner has ceased, then remove to a
position of at least 5 cm above the specimen and leave burning until the
test is terminated.
(3) If the specimen does not ignite within 2 minutes following pilot
burner flame application, the test is terminated by extinguishing the
pilot burner flame. For specimens that do ignite, the test is continued
until the flame goes out. When the test is completed, the door is
opened, and the specimen platform is pulled out.
(4) Measure the distance burned, (the point of farthest advance of
the flame front) to the nearest 0.1 cm (.03 in). From the flux profile
curve, convert the distance to W/cm\2\ (Btu/ft2sec) critical radiant
heat flux at flame out. Read to two significant figures. A suggested
data log format is shown in Figure 10.
(5) Remove the specimen tray from the moveable platform. The
succeeding test can begin as soon as the panel apparent black body
temperature and chamber temperature are verified. The specimen tray
should be at room temperature before the next specimen is inserted.