Dampers

Model HPR-230 industrial pressure relief damper has a double flanged channel frame and streamlined airfoil blades. The damper protects HVAC systems and industrial processes by relieving air pressure.

Blade Type: Fabricated Airfoil
Pressure Relief: ¼ in. wg to 4 in. wg (.06 kPa to 1 kPa)
Back Pressure: 6 - 13½ in. wg (1.5 to 3.4 kPa)
Velocity: Up to 5150 fpm (26.2 m/s)
Temperature: -40°F to 250°F (-40°C to 121°C)

The HPR-330 is an industrial pressure relief damper with double-flanged channel frame. It is designed to protect HVAC systems and industrial processes by relieving air pressure.

Blade Type: Fabricated Airfoil
Pressure Relief: ½ in. wg to 6 in. wg (.012 - 1.5 kPa)
Back Pressure: 13½ - 20 in. wg (3.4 - 5 kPa)
Velocity: Up to 6400 fpm (32.5 m/s)
Temperature: -40°F to 250°F (-40 to 121°C)

The PRAD positive pressure relief door opens automatically at 2 in. wg (0.5 kPa) above normal operating system pressure. These doors prevent ductwork from exploding if system damper(s) close while the fan is still operating.

The VRAD negative pressure relief door also opens automatically at 2 in. wg (0.5 kPa) above normal operating system pressure. This door prevents ductwork from imploding if system damper(s) close while the fan is still operating.