Flat Oval Spiral Duct Look at the under online video to see the installation of oval duct and fittings. Notice that the reducer being used is undersized on its collar allowing the oval duct to slip more than the collar. They are really employing Unistrut with threaded rods as hangers https://holdenjaodq.spintheblog.com/37140345/new-step-by-step-map-for-round-conduit