VI-A-TROL dampers are AMCA certified and tested to AMCA 500 standards. They're certified to -30" w.g. (water gauge) pressure ratings with low-leakage design. AMCA certification verifies that damper performance meets published specifications for airflow control. VI-A-TROL dampers are available from 4" to 120"Ø in round configurations, with rectangular configurations also available. They're manufactured in FRP, PVC, PP, and steel substrate materials to match your ductwork system.

VI-A-DUC® PVC ductwork is FM Approved by Factory Mutual Research Corporation for use in fume exhaust duct systems installed without internal fire sprinklers. The PVC material was tested in accordance with ASTM E-84, with a Flame Spread Rating of 14 and Smoke Development Rating of 754. Ductwork is fabricated in accordance with SMACNA Thermoplastic Duct (PVC) Construction Manual. The PVC material is Type II, Grade I, PVC Class 14333-D per ASTM D-1784, and includes UV radiation inhibitor. All duct components manufactured by Viron bear the FM label.

Viro-Duc® FRP ductwork is FM Approved by Factory Mutual, certified for low flame and low smoke performance. Viron also manufactures FRP duct that is ICBO Approved (International Conference of Building Officials), providing a highly corrosion resistant duct. FRP ductwork specifications reference ASTM standards for material properties and testing procedures. The chemical-resistant FRP uses vinyl ester resin with surface veil reinforcement for maximum chemical resistance.

Standard volume damper flanges are shipped undrilled. This means the bolt holes are not pre-drilled into the flange, allowing you to match your specific bolt pattern and spacing requirements during installation. Dampers are available with plain ends (no flanges) or with flanges attached. When ordered with flanges, the flanges come in standard sizes but without holes drilled, giving you flexibility for field drilling to match your existing ductwork connections. Volume dampers are available in sizes from 4"Ø to 120"Ø with varying duct thickness depending on diameter.

Viron's PVC ductwork systems are designed for 4 inches w.c. (water column) positive pressure for push air ductwork, and 6 inches w.c. negative pressure for exhaust ductwork on the entering side of scrubbers, air washers, or exhaust fans. PVC ductwork is specified for all exhaust ventilation ductwork from tank hood connections to the entering side of scrubbers or fans, and all discharge stacks from scrubbers, air washers, or exhaust fans. The ductwork is fabricated, reinforced, installed, sealed and tested in accordance with SMACNA Thermoplastic Duct (PVC) Construction Manual requirements.