VentAir Systemss is the manufacturer and supplier of Duct Flanges made of G.I. Sheet Material. VentAir Systemss offers air conditioning duct, pre fabricated duct, air conditioning duct, ventilation duct, exhaust duct and duct accessories. The Duct Flanges made of G.I. Sheet Material are supplied in various lengths and quantity as per the pre fabricated duct. Four G.I. Flange channels of required length are riveted at corners to form a flange. These products are used in a wide range of industrial and commercial applications.