Appendix B to Part 179 - Procedures for Simulated Pool and Torch-Fire Testing
49:3.1.1.1.2.8.1.1.8 : Appendix B
Appendix B to Part 179 - Procedures for Simulated Pool and
Torch-Fire Testing
1. This test procedure is designed to measure the thermal
effects of new or untried thermal protection systems and to test
for system survivability when exposed to a 100-minute pool fire and
a 30-minute torch fire.
2. Simulated pool fire test.
a. A pool-fire environment must be simulated in the following
manner:
(1) The source of the simulated pool fire must be hydrocarbon
fuel with a flame temperature of 871 °C plus or minus 55.6 °C (1600
°F plus-or-minus 100 °F) throughout the duration of the test.
(2) A square bare plate with thermal properties equivalent to
the material of construction of the tank car must be used. The
plate dimensions must be not less than one foot by one foot by
nominal 1.6 cm (0.625 inch) thick. The bare plate must be
instrumented with not less than nine thermocouples to record the
thermal response of the bare plate. The thermocouples must be
attached to the surface not exposed to the simulated pool fire and
must be divided into nine equal squares with a thermocouple placed
in the center of each square.
(3) The pool-fire simulator must be constructed in a manner that
results in total flame engulfment of the front surface of the bare
plate. The apex of the flame must be directed at the center of the
plate.
(4) The bare plate holder must be constructed in such a manner
that the only heat transfer to the back side of the bare plate is
by heat conduction through the plate and not by other heat
paths.
(5) Before the bare plate is exposed to the simulated pool fire,
none of the temperature recording devices may indicate a plate
temperature in excess of 37.8 °C (100 °F) nor less than 0 °C (32
°F).
(6) A minimum of two thermocouple devices must indicate 427 °C
(800 °F) after 13 minutes, plus-or-minus one minute, of simulated
pool-fire exposure.
b. A thermal protection system must be tested in the simulated
pool-fire environment described in paragraph 2a of this appendix in
the following manner:
(1) The thermal protection system must cover one side of a bare
plate as described in paragraph 2a(2) of this appendix.
(2) The non-protected side of the bare plate must be
instrumented with not less than nine thermocouples placed as
described in paragraph 2a(2) of this appendix to record the thermal
response of the plate.
(3) Before exposure to the pool-fire simulation, none of the
thermocouples on the thermal protection system configuration may
indicate a plate temperature in excess of 37.8 °C (100 °F) nor less
than 0 °C (32 °F).
(4) The entire surface of the thermal protection system must be
exposed to the simulated pool fire.
(5) A pool-fire simulation test must run for a minimum of 100
minutes. The thermal protection system must retard the heat flow to
the plate so that none of the thermocouples on the non-protected
side of the plate indicate a plate temperature in excess of 427 °C
(800 °F).
(6) A minimum of three consecutive successful simulation fire
tests must be performed for each thermal protection system.
3. Simulated torch fire test.
a. A torch-fire environment must be simulated in the following
manner:
(1) The source of the simulated torch must be a hydrocarbon fuel
with a flame temperature of 1,204 °C plus-or-minus 55.6 °C (2,200
°F plus or minus 100 °F), throughout the duration of the test.
Furthermore, torch velocities must be 64.4 km/h ±16 km/h (40 mph
±10 mph) throughout the duration of the test.
(2) A square bare plate with thermal properties equivalent to
the material of construction of the tank car must be used. The
plate dimensions must be at least four feet by four feet by nominal
1.6 cm (0.625 inch) thick. The bare plate must be instrumented with
not less than nine thermocouples to record the thermal response of
the plate. The thermocouples must be attached to the surface not
exposed to the simulated torch and must be divided into nine equal
squares with a thermocouple placed in the center of each
square.
(3) The bare plate holder must be constructed in such a manner
that the only heat transfer to the back side of the plate is by
heat conduction through the plate and not by other heat paths. The
apex of the flame must be directed at the center of the plate.
(4) Before exposure to the simulated torch, none of the
temperature recording devices may indicate a plate temperature in
excess of 37.8 °C (100 °F) or less than 0 °C (32 °F).
(5) A minimum of two thermocouples must indicate 427 °C (800 °F)
in four minutes, plus-or-minus 30 seconds, of torch simulation
exposure.
b. A thermal protection system must be tested in the simulated
torch-fire environment described in paragraph 3a of this appendix
in the following manner:
(1) The thermal protection system must cover one side of the
bare plate identical to that used to simulate a torch fire under
paragraph 3a(2) of this appendix.
(2) The back of the bare plate must be instrumented with not
less than nine thermocouples placed as described in paragraph 3a(2)
of this appendix to record the thermal response of the
material.
(3) Before exposure to the simulated torch, none of the
thermocouples on the back side of the thermal protection system
configuration may indicate a plate temperature in excess of 37.8 °C
(100 °F) nor less than 0 °C (32 °F).
(4) The entire outside surface of the thermal protection system
must be exposed to the simulated torch-fire environment.
(5) A torch-simulation test must be run for a minimum of 30
minutes. The thermal protection system must retard the heat flow to
the plate so that none of the thermocouples on the backside of the
bare plate indicate a plate temperature in excess of 427 °C (800
°F).
(6) A minimum of two consecutive successful torch-simulation
tests must be performed for each thermal protection system.
[Amdt. 179-50, 60 FR 49078, Sept. 21, 1995, as amended at 75 FR
53597, Sept. 1, 2010; 77 FR 60945, Oct. 5, 2012]