Flat Oval Spiral Duct Watch the underneath video to begin to see the installation of oval duct and fittings. Observe the reducer being used is undersized on its collar enabling the oval duct to slip around the collar. These are applying Unistrut with threaded rods as hangers for your ductwork. https://round-conduit34455.daneblogger.com/35627726/the-single-best-strategy-to-use-for-round-conduit