SECTION 15821

4. Damper: Opposed blade, constructed of steel, adjustable thru face with removable key. USE SUBPARAGRAPH BELOW WHEN DUCTWORK PENETRATES CELL SECURITY WALLS, AND WHEN ANY DUCT DIMENSION IS OVER 6 INCHES. INSTALL SECURITY BARS ON 4 INCH CENTERS. IF DUCT HEIGHT IS OVER 12 INCHES PROVIDE HORIZONTAL SECURITY BARS IN DUCTWORK SO 5 INCH … ................
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