Flat Oval Spiral Duct Watch the underneath video to begin to see the installation of oval duct and fittings. Observe that the reducer being used is undersized on its collar permitting the oval duct to slide over the collar. They can be using Unistrut with threaded rods as hangers for https://round-conduit79901.theideasblog.com/37243472/the-definitive-guide-to-oval-conduit