that are electric-power operated.]
2.2.4
Guides
Steel structural shapes or formed steel shapes fastened to wall with steel
shapes not less than 5 mm 3/16 inch thick. Guides shall be of sufficient
depth or shall incorporate a steel locking bar to retain the curtain in
place under the wind pressure specified. Provide continuous vinyl or
neoprene weather seals on guides at exterior doors. Securely attach guides
to adjoining construction with not less than 10 mm 3/8 inch diameter bolts,
spaced near each end and not over 750 mm 30 inches apart.
2.2.5
Barrel
Steel pipe or commercial welded steel tubing of proper diameter and
thickness for the size of curtain. Deflection shall not exceed one mm per
400 mm 0.03 inch per foot of span. Close ends of barrel with cast-iron
plugs, machined to fit the pipe and either pinned or attached with screws
in the spring barrel, except that drive end plug may be steel welded in
place. Welding shall not be used on the tension end. Install within the
barrel an oil-tempered, stress relieved, helical, counterbalancing steel
spring, capable of producing sufficient torque to assure easy operation of
the door curtain from any position. At least 80 percent of the door weight
shall be counterbalanced at any position.
Spring-tension shall be
adjustable without removing the hood.
2.2.6
Brackets
Fabricate of steel plate or heavy cast iron to support the barrel, curtain,
and operator and to form a supporting ring and end closure for the hood.
Provide prelubricated, self-aligning ball bearings, shielded or sealed.
2.2.7
Hoods
Steel, not lighter than 0.6 mm thick 24 gage formed to fit contour of end
brackets and reinforced with steel rods, or rolled beads at top and bottom
edges. [Hoods for openings more than 3650 mm 12 feet in width shall have
intermediate supporting brackets.] [Provide a weather baffle at the lintel
or inside the hood of each exterior door.]
2.2.8
Locking Device
For each manually operated exterior rolling door provide manufacturer's
standard chain- or bar-type locking device on the inside. The locking
device shall be of type to receive a padlock with a 8 mm 5/16 inch diameter
shackle.
2.3
MANUAL OPERATION
2.3.1
Manual Push-Up Operation
Provide lifting handles on both sides of door and counterbalance in a
manner to provide easy operation while raising or lowering the curtain by
hand. The force required to operate the door shall not exceed 11 kgs 25
pounds. Provide pull-down straps or pole hooks on bottom rail of doors over
2130 mm 7 feet high.
SECTION 08331N
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