Backdraft dampers are used in ventilation systems to allow airflow in one direction and prevent airflow in the opposite direction. A pressure relief damper is developed with an elevated and adjustable start-open pressure while providing the backdraft function.

Hercules Industries Backdraft Damper, 4 in Size, Aluminum, 6 in L

• System velocity and back pressure requirements
• Mounting orientation and airflow direction
• Mounting configuration (inserted into duct/opening or flange-mounted)
• Damper operation (gravity or motorized)
• Start-open pressure

• Specification Sheet https://assets.unilogcorp.com/267/ITEM/DOC/Hercules_Industries_4BDD_Specification_Sheet.pdf