Flat Oval Spiral Duct Watch the under video clip to see the installation of oval duct and fittings. Detect that the reducer getting used is undersized on its collar allowing the oval duct to slip about the collar. They're working with Unistrut with threaded rods as hangers for the ductwork. https://cruzgynbp.blogars.com/35482051/top-oval-conduit-secrets