1.3.2.1
Overpressure
The spatial distribution of overpressure shall be uniform unless otherwise
specified or indicated. [For overpressure specified or indicated without
duration, the overpressure waveform shall have a zero rise time and
infinite duration.] [For overpressure specified or indicated with duration
only, the waveform shall be a triangle with a zero rise time.] [Special
waveforms are indicated.]
1.3.2.2
Overpressure Direction
[For overpressure identified as seating and for overpressure directions not
otherwise specified or indicated, the positive phase overpressure shall be
in the direction that causes the door to seat toward the frame.] [For
overpressure identified as unseating, the positive phase overpressure shall
be in the direction that causes the door to unseat away from the frame.]
1.3.2.3
Fragment Resistance
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NOTE: Fragment design parameters will be determined
in accordance with TM 5-1300, chapter 2 and TM
5-855-1 as applicable. Exposing blast doors to
primary fragments is not recommended because of the
resulting severe damage to hardware, because molten
fragments can weld the door to the frame preventing
post-blast opening, and because it is difficult to
prevent perforation at the door edges. Also, while
latches and latch mechanisms can be protected, it is
usually not practical to protect the hinges.
Worst-case fragment perforation of the door can be
prevented for structural steel and reinforced
concrete doors by specifying fragment
characteristics or a minimum plate or concrete
thickness in the door assembly paragraph.
The 100 and 200 mm (4 and 8 inch) reinforced
concrete nominal thickness shown are typically
available.
Hollow metal doors cannot prevent perforation by
primary fragments and will not be used for this
purpose.
Fragment parameters or door thickness will be
specified in paragraph BLAST DOOR ASSEMBLIES.
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For doors specified or indicated to resist fragments, the door and the door
and frame interface shall be designed to prevent fragment perforation and
the latches and latching mechanism shall be shielded from fragment damage.
The fragment impact point shall be anywhere on the door and frame face
exposed to overpressure.
1.3.3
Blast Door Operation
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NOTE: Specify swing forces of 90 and 70 N (20 and
SECTION 08390
Page 14
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