[Code of Federal Regulations]
[Title 16, Volume 2]
[Revised as of January 1, 2004]
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 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 C (69.89
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
C (350 F) of 1.11 cal (g)/hr cm\2\
C/cm [0.89 Btu/(hr) (ft\2\) (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 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
C (914-950 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 C
(212-932 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 C (59-77 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 C (932 F),
and bring the chamber to a temperature of approximately 180
C (356 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 C (69.85.4 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 C
(69.85.4 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
C (9 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.