Furnish and install, at locations shown on plans, or in accordance with schedules, Low leakage dampers shall meet the following minimum construction standards: Frames shall be 4” x 1” (102 x 25) 6063T6 extruded aluminum channel. Blades shall be airfoil type extruded aluminum with integral structural reinforcing tube running full length of each blade. Blade edge seals and finger style jamb shall be Santoprene and be mechanically locked in extruded slots. Adhesive or clip-on type blade seals are not acceptable. Bearings shall be non-corrosive molded synthetic. Axles shall be hexagonal (round not acceptable) to provide positive locking connection to blades and linkage. Linkage shall be concealed in frame. Damper widths from 12” to 60” (305 to 1524) wide shall not leak any greater than 8 cfm sq. ft. @ 4” w.g. and a maximum of 3 CFM sq. ft. @ 1” w.g. Dampers shall be in all respects equivalent to Ruskin Model CD450.
4.3 
