 ROLLING
DOORS As manufactured by The City Gates Mfg. Corp.,
College Point, N.Y. shall be of service type and operated
by means of either manual push-up, endless chain or
motor.
WORK EXCLUDED Preparation of openings, structural
supports, access panels, trim, field painting. On motor
operated doors, exclude wire, wiring or disconnect switches.
CURTAINS to be composed of interlocking slats
of (galvanized steel) (aluminum) (stainless steel) ,
designed to withstand a windload of 20 Ibs. per sq.
ft. Windlocks to be applied where required by opening
span or heavier windload. Galvanized steel slats to
be from hot dipped copper bearing strip, with 1.25 oz./sq.
ft. zinc coating, and phosphate coated for paint adhesion.
Strip to conform to ASTM standards. For doors up to
14'-0 wide slats to be #22 Gauge; from 14'-0 to 18'-6
wide slats to be #20 Gauge; over 18'-6 wide, slats to
be #18 Gauge. Alternate slats to be fitted with malleable
iron endlocks. Bottom of curtain to have reinforcing
angles of (steel) (aluminum) (stainless steel)
COUNTERBALANCE ASSEMBLY to consist of helical
torsion springs with a 25% safely factor, mounted on
shaped cast anchors, supported by a continuous solid
torsion rod. This mechanism to be permanently lubricated
and enclosed within a steel pipe shaft , Deflection
of shaft not to exceed .03" per lin. ft. The spring
tension adjusting wheel is to be readily accessible
from outside the bracket plate.
BRACKETS to be not less than 1/4" thick steel
plate, to contain self aligning ball bearings for suspension
of the counter balance assembly. Brackets to be mounted
to the structural wall angle to form a self supporting
member, and form an enclosure to the hood. Brackets
to be reinforced with welded steel bands for support
of hoods. Gears to be of high grade iron, cast from
machine cut patterns.
GUIDES To be composed of structural (steel)
(aluminum) (stainless steel) angles, minimum 3/16" thick,
of sufficient depth to retain curtain under normal wlndload.
For doors requiring windlocks, guides to be provided
with windlock bars. Guides to be assembled with 3/8"
diameter bolts spaced not over 3'-0" on centers.
HOODS to be not less than #24 gauge (hot galvanized
phosphate treated steel) (aluminum) (stainless steel),
formed to fit brackets, and reinforced top and bottom
with stiffening returns, with intermediate hood supports
where required by door width.
LOCKING provision for padlocks to be (slide
bolts on push up doors) (chain holder on chain doors)
(locking disc on crank doors) (self-locking gearing
on motor operators).
FINISH on steel to be one shop coat of rust
inhibiting metal primer, except on galvanized surfaces.
On aluminum, finish to be mill. On stainless steel,
finish to be 2B mill. |
