1,Special design for Eroupe duct flange Standard , 2,L shape, U shape, All wraped duct section with formed connections DUCT LINE-7GDF ... Pittsburgh lock ,beaded and Duplex GDF flange,Automatically bending “L”,“U”,“Wrap”section and seam close,The customer can choice ... require.This line uses an enhanced rack Industry CNC control system and MEIFOMER speical duct manufacture software.PLC&coputer control,, ...