Model BT-91
Bubble-Tight Damper
Single Blade - Rectangular
The BT-91 is an industrial control damper designed for isolation and decontamination applications. Bubble-tight dampers are designed to have the lowest leakage ratings possible. Typical applications include industrial processing plants, laboratories, clean rooms, pharmaceutical facilities, nuclear facilities, DOE facilities, and other applications that require extremely low leakage. The BT-91 is tested for bubble-tight leakage ratings in accordance with AMCA 500-D up to 10 in. wg (2.5kPa). The damper frame is flanged for easy mounting and the blade seal is mechanically fastened to the blade.
Standard Construction
Frame: Steel channel
Blades: Steel
Blade Seals: Silicone rubber, mechanically fastened to blade
Blade Stop: Full open and closed position pin stop
Blade Style: Parallel rectangular steel blade; reinforced where required
Axles: Plated steel
Axle Seals: Double gland
Bearings: Relubricable ball bearing, outboard mounting
Control Shaft: 6" (152) long round drive axle
Finish: Hi-Pro poly powder coat, gray (Two year warranty)
Minimum Size: 6" × 6" (152 × 152)
Maximum Size: 48" × 52" (1219 × 1321)
Lifting Lugs: Two 1" (25) lifting lugs provided on dampers > 16" (406) wide and/or tall, one on each jamb of frame
Ratings
Leakage: Bubble-tight in accordance with AMCA-500D
Velocity: Up to 4,000 fpm (20.3 m/s)
Temperature:
Minimum: -40oF (-40oC)
Maximum: 250oF (121oC)
Pressure: Up to 10.0 in.wg. (2.5 kPa) - differential pressure
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