The quicker way to stiffen rectangular ductwork

To increase the strength and rigidity of rectangular ductwork, CCL Veloduct offers the Type S stiffener. Much less time is required to fit this product compared with traditional angle iron. Overall time savings of 20 to 30% are estimated, depending on the size of duct. These stiffeners can be fitted before or after ductwork has been installed. Sections are made from galvanised steel and comprise a right-angle profile with a roll-over finish to one side. Fixing centres are rolled into the stiffeners during manufacture to eliminate marking out and reduce fitting time. To make a stiffening frame, four sections of profile are cut to match the ductwork dimensions and fixed by spot welding or fasteners using pre-punched dimples No secondary protection is required. Type S stiffeners come in two sizes; DVS2 has an S2 rating and DVS4 and S4 rating. Both comply with Fig. 19 of HVCA specification DW/144.