Good points

Ø 100 mm
Air tightness class 2
Sendzimir galvanised
Return damper blades

Spiral duct check valve Ø 100 mm

Installing an inline back draugt shutter between ventilation ducts prevents backflow of ventilation air. In addition, air from outside will also not be able to enter the duct. The two non-return valve blades will open or close by means of the air pressure in the spiral duct. This check valve is suitable for a 100 mm diameter duct.

Material
The back draugt shutter is manufactured to the highest standards. They are galvanised (Z275) according to the sendzimir process, which makes them durable in use and guarantees a long service life.

Air tightness class
The spiral duct check valve meets the strict requirements for airtightness class D (ATC 2), according to standard EN12237.