3.1.7.4
Tightness
Penetration shall be [weathertight] [fireproof where fire rated surfaces
are penetrated] [vaportight to prevent vapor transmission to conditioned
spaces] [sound tight to prevent sound transmission to or between normally
occupied or finished spaces] [deleterious or hazardous substance-tight
where] [toxic] [flammable] [_____] [substances or gases could migrate].
3.1.7.5
Sealants
Provide sealant of [_____] [elastomeric] type [or foamed silicone type], as
specified under paragraph entitled "Sealants," in this section. Apply to
oil free surfaces to a minimum 10 mm 3/8 inch depth.
3.1.7.6
Closure Collars
Provide a minimum 100 mm 4 inches wide, unless otherwise indicated, for
exposed ducts and items on each side of penetrated surface, except where
equipment is installed. Install collar tight against the surface and fit
snugly around penetrating item without contact. Grind sharp edges smooth
to prevent damage to penetrating surface. Fabricate collars for round ducts
380 mm 15 inches in diameter or less from 20 gage, 1.00 mm 0.0396 inch
nominal thickness, mill galvanized steel. Attach collars a minimum of 4
fasteners to where the opening is 300 mm 12 inches in diameter or less, and
a minimum of 8 fasteners where the opening is 500 mm 20 inches in diameter
or less. Fabricate collars for square and rectangular ducts with a maximum
side of 380 mm 15 inches or less from 20 gage, 1.00 mm 0.0396 inch nominal
thickness, mill galvanized steel. Fabricate collars for round, square, and
rectangular ducts with minimum dimension over 380 mm 15 inches from 18 gage,
1.40 mm 0.0516 inch in nominal thickness, mill galvanized steel. Install
collars with fasteners a maximum of 150 mm 6 incheson center. [Where
penetrating items are irregularly shaped and where approved, smoothly
finished, fire-retardant, foamed silicone elastomer may be utilized without
closure collar.]
3.1.8
Installation of Fire Dampers
Install fire dampers at locations indicated. Provide units and connecting
ductwork in accordance with applicable provisions of [NFPA 91,] [UL Bld Mat
Dir,] AMCA 500-D [and UL 33], [and as indicated]. Install retaining
angles, sleeves, break-away connections, and duct access doors at each
damper, as required. Minimum thickness of sleeves shall be 14 gage [,
except as otherwise indicated]. Duct access doors shall be hinged [and
fitted with UL listed glass viewing port assembly]. Prior to acceptance,
simulate conditions to cause each unit to function automatically. Apply
safe, nonflame, heat source to fusible links and replace test activated
fusible links.
3.1.9
Installation of Flexible Connectors
Flexibly connect duct connected and vibration isolated fans [, ducts
crossing building expansion joints] and specified or indicated components
[, except where direct connections are specified or indicated]. When fans
are started, stopped, or operating, flexible connector surfaces shall be
curvilinear, free of stress induced by misalignment or fan reaction forces,
and shall not transmit vibration. Leakage shall not be perceptible to the
hand when placed within 150 mm 6 inches of the flexible connector surface
or joint. Provide a minimum of 150 mm 6 inches and a maximum of 610 mm 2
feet active length with a minimum of 25 mm one inch of slack, secured at
SECTION 15801N
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