Flat Oval Spiral Duct View the under movie to begin to see the installation of oval duct and fittings. Notice which the reducer being used is undersized on its collar letting the oval duct to slide about the collar. These are applying Unistrut with threaded rods as hangers for that https://ovalconduit12233.blogspothub.com/35618061/oval-conduit-no-further-a-mystery