94 FEATURES Made from premium grade extruded aluminium. Suitable for use in corrosive environments like swimming pools or coastal areas. Nylon long life bearings ensure smooth and quiet operation. Blades individually hinged on stainless steel stub shafts. Supplied as overall size as standard. Foam blade tip seals to reduce rattling. Maximum width 500mm per section. DESIGN DETAILS (mm) ADNRD 12 OVERALL SIZE AIRWAY SIZE 65 SPACES 78 Damper NON RETURN DAMPER Model ADNRD APPLICATIONS Non Return Dampers, also known as back draft dampers, are suitable for situations requiring a single direction of airflow to be maintained. These dampers are operated only by air pressure. When the air flows in the desired direction the blades open, however when the air flows in the wrong direction the blades are forced shut. Dampers can be installed inside rigid ductwork, plenums or in-line applications with flanged ductwork.