?Material?The 4 inch backdraft damper is made out of a Galvanized steel, the flap leaves are made of aluminum, while the Axis and spring are made of stainless steel.
?Installation?The backdraft damper is installed by pushing it into the ventilation pipe as far as it will go. The position of the spring should be horizontal when the flap is installed horizontally so that it can be opened and closed optimally. This also applies to the vertical installation.
?Function?This airflow regulating backdraft shutter fits over the TD lip and is designed to improve ventilation by preventing air from re-circulating when the fans are not in use.
?Wide Application? These backdraft dampers can be widely used in ACs, exhaust fans, extractors, range hoods, heating ducts, vents and other residential, commercial and industrial applications.
?Note?Back draught valves can be inserted into ventilation ducts which are flexible or non flexible. Cannot be used with plastic ducts as the sizes are different.