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DocuSign Envelope ID: E9612703-F25B-492D-9C8C-EC3F9728ECE6 <br /> 13" to 30" 24 ga. .025" <br /> 31" to 60" 22 ga. .031" <br /> 61"to 90" 20 ga. .0375" <br /> Over 90" <br /> C. Joints: <br /> Longitudinal joints in ducts not exceeding 50 inches in either dimension and in ducts exceeding 60 <br /> inches in the large dimension but not exceeding 18 inches in the smaller dimension shall be inside <br /> grooved seams, standing seams,sliding corner seams,Pittsburg lock seams, or equal. Longitudinal <br /> joints in all other ducts shall be inside standing seams. <br /> Ductmate or W.D.C.I.proprietary duct connection systems will be accepted. Duct constructed using <br /> these systems will refer to the manufacturer's guidelines for sheet gauge,intermediate reinforcement <br /> size and spacing, and joint reinforcements. <br /> All ducts shall be strongly and rigidly constructed and joints shall be mechanically tight as well as <br /> substantially air tight. <br /> Transverse joint and bracing angles shall be as follows: <br /> Duct Size-Long Size Transverse Joint Bracing Angles <br /> 18" or less S-slip & drive cap None <br /> 19"to 24" 3/4" bar slip & drive cap None <br /> 25"to 42" 1" bar or pocket slip 1"x 1" x 1/8" <br /> 43"to 90" 1-1/2" bar or pocket slip 1-1/2"x 1-1/2"x 1/8" <br /> D. Dampers & Splitters: <br /> Dampers and splitters shall be installed in ducts at all branches where shown on drawings and <br /> wherever required to permit complete adjustment of air quantities. A splitter or opposed blade <br /> dampers shall be installed in each branch duct serving four or more outlets,and wherever shown,in <br /> addition to dampers,or other means of volume control provided at the outlets. Dampers and splitters <br /> shall be located where they can be adjusted at any time after completion of work, means of <br /> adjustment and access panels being furnished as required. Dampers on main branch lines shall be <br /> manufactured opposed blade type items. <br /> Control dampers shall be equal to Ruskin type CD50- 10 CFM per square foot at 4"W.C.maximum <br /> leakage. Splitters shall be manufactured type. <br /> E. Stiffeners: <br /> 15H-26 <br />