The HB-330 heavy duty industrial backdraft damper features a double flanged galvanized steel frame and double thickness fabricated airfoil blades. External heavy duty linkage, blade counterbalance and ball bearings all are standard.
Pressure: Up to 20 in. wg (5 kPa)
Velocity: Up to 6400 fpm (32.5 m/s)
Temperature: -40°F to 250°F (-40°C to 121°C)
