Volume Damper Low-Leak OBD 3000-0BDLL-28X18 Smoke-Fire Damper 850 Series Engineering/Performance Data

850 Series Engineering/Performance Data

904 - Double Deflection Adjustable Aluminum Blade Grille For a 20" x 8" Duct Opening  (front blades parallel to shortest dimension)

3/16” crossbars

Double deflection radius mount spiral pipe grille with adjustable blades

955 Series Engineering/Performance Data

Volume Damper Low-Leak OBD 3000-0BDLL-28X18 Smoke-Fire Damper 850 Series Engineering/Performance Datah3. Standard Features * Opposed blade operation for precise volume control * 16 gauge galvanized channel frame * Blades are vee stiffened 16 gauge galvanized for strength and stability * Blades pivot on non metallic celcon bushings * 1 2" square zinc plated steel pivot pins * 1 2" square zinc plated steel adjustable operating shaft extending up to 4" beyond the air control frame * Single blades on dampers with a height of 12" or less * Mill finish h3.