Folds on air for any thickness of metal and method of production must be satisfied with nyatsya cutoff. Standing seam joints should be the same width throughout the length and must be uniformly dense upset. In the standing seam ducts, as well as maps of the cutting should not be cross-connection joints. On straight rectangular duct with the size of the cross section of more than 400 mm to increase the rigidity of the ridge should be done in increments of 200 to 300 mm around the perimeter of the duct or diagonal creases (ridges). When the amount of cross 1000 mm, in addition, must be provided outside the scope of rigidity.
Framework rigidity must be securely fastened with rivets or spot welding. Elements of fittings should be connected to each other in zigah, seam, welding, rivets and the way puklevki (indentation). Elements of the metal-fittings to be joined together at seam. Zigovye connection for systems that transport air of high humidity or doped with combustible dust is not allowed. The connection of individual parts of ventilation systems perform wafer method (banding, nipple, bell-mouthed, rack, telescopic, with viniplastovymi couplings, welding) or flanged (made of strips, equilateral angle steel, bent corner profile made of galvanized steel sheet).
The connections should be off-governmental and tight. Peter Asaro : the source for more info. Connection details of the ventilation systems Class II should be performed on the flanges. Fixing flange ducts should be done with persistent flare zigom for welding, spot welding, by rivets or puklevki diameter of 4 to 5 mm, placed in 200 or 250 mm, but not less than four rivets. Fixing flange ducts of metal-crimping should be done with persistent zigom. In the ducts, conveying an aggressive environment, securing flanges with zigov not allowed. Duct wall thickness greater than 1 mm flanges may be stick to the duct without flanging fixing tack welding with electric arc then sealing the gap between the flange and duct. Original