BAROMETRIC RELIEF DAMPER
ADJUSTABLE COUNTERBALANCE
DAMPERS AND LOUVERS
BR-30 SERIES
Vertical Mount Horizontal Airflow
Application and Design
The BR-30 series is an eccentrically pivoted backdraft damper for low velocity systems. BR-30 series is a vertical mounted
damper and designed to allow horizontal airflow and prevent reverse airflow. To increase sensitivity and reduce blade mounted
counterbalance, the blade skin is formed aluminum. On-blade counterweights are provided to fine tune start-to-open and full
open blade operation. Ball bearings minimize friction.
Recommended Applications:
• Gravity hood intake and exhaust
• Stairwell pressurization
• Room pressurization
W*
• Ductwork outlets
Poor Applications:
• Propeller fan outlets (high velocity)
• Centrifugal fan outlets (high velocity)
• Building pressurization (sensitive to wind)
• Pressure relief exceeding 0.13 in. wg (32 Pa)
Ratings
Back Pressure: 2.0 in. wg (500 Pa)
Start-to-Open Pressure: 0.05 in. wg (12 Pa)
H*
Velocity: 2000 fpm (10.2m/s)
Temperature: 180°F (82ºC)
Standard Construction
Frame: Insert mount 16 ga. (1.5mm) galvanized steel
hat channel
*W & H dimensions furnished approximately 1/4 in.(6mm) under size.
Blades: 0.063 in. (1.6mm) thick formed aluminum,
eccentrically pivoted
3
Axles: /8 in. (9.5mm) square plated steel
1.5 in.
1.5 in.
Bearings: Galvanized steel press-fit ball
Linkage: Side mounted (out of airstream)
Blade Seals: Pressure activated vinyl
Counterbalance: Blade mounted with adjustable
weights
4 3/8 in.
MAX
1 in.
MAX
Size Limitations
Airflow
Minimum Size: 8 in. W x 6 in. H
(203mm x 152mm)
Maximum Panel Size: 48 in. W x 74 in. H
(1220mm x 1880mm)
5 in.
Options
• EPDM segmented jamb seals
• Stainless steel or aluminum frame
• Stainless steel axles and linkage
BR-32
Flange on
Intake
BR-30
No flange
BR-31
Flange on
Discharge
• Type 316 ball bearings with acetal races
• Selectable start open from .05 to .13 in. wg (12 Pa - 32 Pa)
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