Test
Al Mabani rectangular , cross talk & circular sound attenuators are tested in accordance with BS 4718 : 1971. “Methods of Test for silencers for Air Distribution Systems”. These tests were carried out by the Sound Research Laboratories Limited(SRL) in Sudbury, Suffolk, U.K.
Material
All Al Mabani attenuator are constructed of lock forming quality galvanized steel sheets with Z275g/sqm as per ASTM A924 and ASTM A653
Attenuators are also available in the following materials:
– Stainless steel as per ASTM 240 type 304 or 316.
Acoustic Infill
Al Mabani use fiber glass insulation with woven glass cloth facing as the standard acoustic infill. The material is inert, non-flammable,
non-hygroscopic, will not sustain vermin or fungus, rot proof and odorless. The “Acoustic Infill” shall be faced with glass tissue or equivalent. The infill material is guaranteed against erosion up to air velocities of 30 m/s and temperatures up to 121oC.
The acoustic infill tested to the following tests:
- Surface Burning Characteristics: UL 723, ASTM E84, ASTM E136
- Mold Growth: ASTM D2020, UL 181
- Moisture Absorption: ASTM D-07 B, ASTM C550
- Fire Resistance: NFPA 90A
- Acoustic Performance: ASTM C1071, ASTM C423-77