Flat Oval Spiral Duct Observe the down below movie to see the set up of oval duct and fittings. Notice the reducer getting used is undersized on its collar enabling the oval duct to slide over the collar. These are applying Unistrut with threaded rods as hangers with the ductwork. https://oval-conduit67899.bloggactivo.com/35762432/a-simple-key-for-round-conduit-unveiled