Air supply/exhaust grilles are installed directly and lengthwise on the round ducts and fastened with screws. The grille has been designed so that the bezel flange fits tightly to the round surface of the duct, whatever the duct diameter. The grille is made of galvanized steel sheet without tack or seam welds. As a result, it requires no anti-corrosion protection and its finish matches that of the ductwork. The grille can be optionally fitted with single or double louvre blades positioned horizontally and vertically. The louvre blade angle is adjusted manually. The air grille can also be fitted with the SGR-DA sliding angle damper.
The SGR-DA sliding angle damper is designed for installation on the SGR air grilles intended for round ventilation ducts. The damper is provided with separate clips for mounting on the air grille. The SGR-DA dampers provide a means to control the air flow rate, air flow speed and air flow range. The damper outlet grate is set at an angle to the air grille surface. The air flow is adjusted by repositioning the damper closure behind the damper grate.