Models ALRA, ALRB, and ALRC provide improved LOW FREQUENCY performance to solve the toughest noise
Special features of the LOW FREQUENCY tubular attenuators include:
problems. Unit width is diameter plus 16”. Standard unit length is two times the diameter, minimum 36,”
plus 2” long collars on each end.
ASTM E-84 ratings for the acoustical fill are:
- Radius spun inlet note on center
absorber to provide minimum
- Available in one inch diameter increments from
10” - 22” and 2” diameter increments from
24” - 60”.
- LR model casings:
- 12” - 24” diameter - 22 ga. galvanized steel
- 26” - 60” diameter - 18 ga. galvanized steel
- 24 gauge perforated galvanized baffles
- Long strand Fiberglass acoustical fill
- Seams are roll formed and mastic filled to insure airtight units to 8” w.g.
- Optional polyethylene, Mylar or fiberglass cloth liners
- Flamespread 10
- Smoke Developed 10
Components also available in stainless steel or aluminum construction.
Acoustical performance ratings are based on tests conducted by Intertek Testing Services, formerly ETL Testing Laboratories, Inc., Cortland, New York,
in accordance with ASTM E477 “Standard Method of Testing Duct Liner Materials and Prefabricated Silencers for Acoustical and Airflow Performance.” Copies of the test reports are available upon request.