... 2 -TDC Duct Connection: Flange, Corner, G-clamp Air Duct, Duct Flange, Duct Corner Duct Corner TDC Corner : For Transverse Duct Connector system, the ... .0mm , 2.5mm , 3.0mm , 3.5mm ,4.0mm TDF Corner : For Transverse Duct Flange system, the flange is formed from ... China. Our annual processing capacity reaches 120 000 tons (1.5 million M2). We operates 4 efficient production sites for galvanized ...