Products» Air Pollution Control»»GFRP Dampers and Ducts Amerair is supplier of Glass Reinforced Plastic Dampers and  Ducts;  Dampers are available for each size from DN100mm to 2000mm. Both  manual and auto actuated types are supplied. Dampers with internal  seals insure minimal air leakage.  Ducts and joints are available in stiffness classes of 1250,  2500, 5000 and 10000 Pa. In nominal pressure classes, it is  available in PN3, PN6, PN10, PN16 and PN20. These pipes are  designed to withstand aggressive environments both for  pressure and gravity applications and available in Nominal  Diameters (DN) from 300mm to 2600mm, AWWA C950, O.D.  series.  Copyright © Amerair International 2008 Air Pollution Control & Monitoring