Flat Oval Spiral Duct View the underneath movie to see the installation of oval duct and fittings. Detect which the reducer being used is undersized on its collar letting the oval duct to slide more than the collar. These are using Unistrut with threaded rods as hangers to the ductwork. https://roundconduit79901.creacionblog.com/36393699/oval-conduit-fundamentals-explained