For automatic shut-off of the air ducts and prevention of back drafting when the fan off. Suitable for installation in various premises. Compatible with Ø 100 up to 315 mm round air ducts.
Fixing to round ducts with clamps. Provide free gravity actuated movement of the blade. Install the backdraft damper into the ventilation system with respect to the air flow direction.
Galvanized steel case and rotary gravity-actuated blade. Airtight connection with the air ducts due to rubber seals. The damper blade is opened with air pressure and reset automatically when the fan is off and no air pressure is produced. Manual handle with a counterweight to regulate the damper opening-closing sensitivity.