2.5.1
General
Material in shielded doors and frames shall be steel conforming to ASTM A
36/A 36M or ASTM A 568/A 568M and shall be stretcher-leveled and installed
free of mill scale. Metal shall be thicker where indicated or required for
its use and purpose. Metal thresholds of the type for proper shielding at
the floor shall be provided. Fire rated shielded doors and assemblies
shall meet NFPA 80 and NFPA 80A requirements and shall bear the identifying
label of a nationally recognized testing agency qualified to perform
certification programs. The EM shielded doors shall be provided by a
single supplier who has been regularly engaged in the manufacture of these
items for at least the previous 5 years. The assemblies shall be supplied
complete with a rigid structural frame, hinges, latches, and parts
necessary for operation. The products supplied shall duplicate assemblies
that have been in satisfactory use for at least 2 years. The door frame
shall be steel suitable for [welding] [bolting] to the surrounding
structure and shield. The EM filters, EM waveguide penetrations for door
systems, and miscellaneous material shall be provided for a complete
system. The enclosure door shall be nonsagging and nonwarping. The EM
shielded door shall provide a shielding effectiveness of [10 dB] [20 dB]
greater than the minimum EM shielding effectiveness requirements. The door
shall have a clear opening [as shown on the drawings] [of [915] [_____] mm
[36] [_____] inches wide and [2135] [_____] mm [84] [_____] inches] high.
The door and frame assembly shall have a sound rating of STC [30] [_____]
minimum. Testing shall be performed in accordance with ASTM E 90.
2.5.1.1
Door Latch
The door latch shall be lever controlled with roller cam action requiring
not more than 67 N 15 pounds of operating force on the lever handle for
both opening and closing. The door shall be equipped with a latching
mechanism having a minimum of three latching points that provides proper
compressive force for the EM seal. The mechanism shall be operable from
both sides of the door and shall have permanently lubricated ball or thrust
bearings as required at points of pivot and rotation.
2.5.1.2
Hinges
Doors shall be equipped with a minimum of three well-balanced adjustable
ball-bearing or adjustable radial thrust bearing hinges suitable for equal
weight distribution of the shielded doors. Hinges shall allow adjustment
in two directions. Force necessary to move the doors shall not exceed 22 N
5 pounds.
2.5.1.3
Threshold Protectors
Threshold protectors shall be furnished for each EM shielded door.
Protectors shall consist of portable ramps that protect the threshold when
equipment carts or other wheeled vehicles are used to move heavy items
across the threshold. The ramps may be asymmetrical to account for
different floor elevations on each side, but the slope of the ramp shall
not exceed 4:1 on either side. Ramps shall be designed to support a [227]
[_____] kg [500] [_____] pound vertical force applied to a 75 x 13 mm 3 x
1/2 inch area for a personnel door, and a [907] [_____] kg [2,000] [_____]
pound vertical force applied to a 75 x 13 mm 3 x 1/2 inch area for an
equipment double leaf door. The force shall be applied to the contact area
between the threshold and the door. Mounting brackets, convenient to the
entry, shall be provided to store the ramp when not in use.
SECTION 13095A
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