Couplings slip inside the ends of two round ducts being joined together after which sheet metallic screws are fixed to hold it set up. Couplings could be demanded at a certain measurement including connections 18” and larger. The shaded area in the impression beneath may be the coupling. Everytime you https://simonbxqhx.worldblogged.com/42742316/a-simple-key-for-round-conduit-unveiled