Reinforcement rings are normally not needed for constructive strain and lower destructive tension round ducts. The use of rings helps manage the roundness of your duct as being the measurements get greater. Everytime you have a piece of duct tapping in the facet of Yet another duct you will require https://ovalconduit23445.blogsidea.com/43190190/round-conduit-can-be-fun-for-anyone