SA B 20 Series - AMCA

Type: Square and Rectangular
Model: 2 Hrs @ 400°C
Construction: Galvanized Steel / Stainless Steel


BETEC CAD. manufactures square, rectangular, cylindrical and cross talk sound attenuators, which are used in commercial, industrial and residential buildings to reduce mechanical equipment noise transmitted through the ducted or un-ducted system achieving desired noise criteria in the occupied space. We design attenuators to achieve desired noise criteria in the occupied space or to reduce environmental noise for generator rooms, to meet
project requirements without compromising attenuator performance.

Economical results are obtained by using properly designed BETEC CAD. factory calibrated/fabricate Sound Attenuators.

BETEC CAD.’s Sound Attenautors are tested for fire integrity of 2 Hrs @ 400°C.


Standard Construction


0.9 mm thick galvanized steel sheet.


0.7 mm / 0.9 mm thick Ø3 mm hole perforated galvanized steel sheet.


48 kg/m³ Density rockwool coverd with Black glass tissue.


25 mm Ductmate flanges on both ends.

Optional Fittings


Mild steel angles with red oxide or zinc coating, having Ø8 mm holes at a pitch of 250 mm. Alternate hole pitch available on customer request.

Optional Construction

Casing :

Thickness Up to 3 mm

Splitters :

0.9 mm thick Ø5 mm hole perforated galvanized steel sheet.

Casing and Splitter Material :

Stainless Steel (304/316L)


48 kg/m³ Density fiberglass wool covered with black glass tissue.


• BETEC CAD.’s B20 series Sound Attenuators are aerodynamically designed with bullnose splitters at inlet for square and rectangular type. The standard construction is suitable to withstand a maximum pressure of 2000 Pa.
• Square and Rectangular type sound attenuators are designed for handling maximum air capacities at minimum pressure drop.
• The turbulence of the airflow is minimized due to the bullnose design of the splitter at the air inlet.
• Solid curved splitter face minimises noise generation at the air inlet.
• Acoustic infill media is of superior quality, non combustible and has fungi resistant characteristics complying to and ASTM C 612
• These sound attenuators are maintanance free.


Sound attenuators are designed to attenuate noises of fans, air-conditioning devices in ventilation and air-conditioning systems , Air Handling Units, Fan Inlet and
Discharge , Generator rooms and HVAC Duct Systems.

BETEC CAD. sound attenuators are suitable for DW 142 class C applications. Attenuator constructional integrity is suitable for pressures up to 2000 pa. Sound Attenuators are tested and certified by INTERTEK USA for ASTM standard E477-13 entitled “ Standard
method for Laboratory Measurements of Acoustical & Airflow performance of Duct liner materials & Prefabricated Silencers”

Note : Please contact BETEC CAD. for customized design and specification.



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