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Blauberg VRVS 40x20

Backdraft air damper for rectangular duct.
EAN codeEAN4058448042249
  • Description
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  • Overall dimensions
  • Designation key

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 400x200 up to 600x350 mm rectangular air ducts.


Fixing to rectangular ducts in upright position. 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. 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.

Parameter VRVS 40x20 Measurement unit
Connected air duct size 400х200 mm
Weight 2.9 kg
Casing material galvanized steel -
Air duct for rectangular air ducts -
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VRVS (rectangular) - data sheet (pdf 224.11Kb)
VRVS (rectangular) - image (png 443.28Kb)
Overall dimensions
Overall dimensions

Model Dimensions [mm]
B B1 B2 H H1 L
VRVS 40x20 400 440 461 200 240 202
Designation key
Designation key
Series Flange size [cm]
VRVS 40x20; 50x25; 50x30; 60x30; 60x35