the duct in which installed. Unless otherwise indicated, multileaf dampers
shall be opposed blade type with maximum blade width of 300 mm 12 inches.
Provide access doors or panels for all concealed damper operators and
locking setscrews. Unless otherwise indicated, the locking-type quadrant
operators for dampers, when installed on ducts to be thermally insulated,
shall be provided with stand-off mounting brackets, bases, or adapters to
provide clearance between the duct surface and the operator not less than
the thickness of the insulation. Stand-off mounting items shall be
integral with the operator or standard accessory of the damper manufacturer.
2.6.2.4
Automatic Smoke-Fire Dampers
**************************************************************************
NOTE: Use this paragraph for Navy projects only.
When this paragraph is not used, delete "Automatic
Smoke-Fire Dampers" from the submittal list.
For smoke-fire dampers, use UL 555S Class III,
unless the particular building and application such
as hospital dictates the use of UL 555S Class II
instead.
**************************************************************************
Multiple blade type, 82 degrees C 180 degrees F fusible fire damper link;
smoke damper assembly to include pneumatically powered operator. UL 555 as
a 1.5 hour rated fire damper; further qualified under UL 555S as a leakage
rated damper. Leakage rating under UL 555S shall be no higher than Class
[II] [or] [III] at an elevated temperature Category B (121 degrees C 250
degrees F for 30 minutes). Pressure drop in the damper open position shall
not exceed 25 Pa 0.1 inch water gauge with average duct velocities of 13
m/second 2500 fpm.
2.6.2.5
Automatic Smoke Dampers
**************************************************************************
NOTE: Use this paragraph for Navy projects only.
When this paragraph is not used, delete "Automatic
Smoke Dampers" from the submittal list.
For smoke-fire dampers, use UL 555S Class III,
unless the particular building and application such
as hospital dictates the use of UL 555S Class II
instead.
**************************************************************************
UL listed multiple blade type, supplied by smoke damper manufacturer, with
pneumatic damper operator as part of assembly. Qualified under UL 555S
with a leakage rating no higher than class [II] [or] [III] at an elevated
temperature Category B (121 degrees C 250 degrees F for 30 minutes).
Pressure drop in the damper open position shall not exceed 25 Pa 0.1 inch
water gauge with average duct velocities of 13 m/second 2500 fpm.
2.6.2.6
Air Deflectors and Branch Connections
**************************************************************************
NOTE: Air deflectors are for Army and Air Force
projects only.
**************************************************************************
SECTION 15895
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