Flanged joints are made by bending the top with the raw duct or fitting to produce a ¼” flange. Below could be the code portion for your International Mechanical Code with the permitted welded duct connections forms. In all instances the joints and seams are going to be welded, the https://commercial-kitchen-extrac46789.bloggerchest.com/37016174/grease-tight-extract-ductwork-fundamentals-explained