Flanged joints are made by bending the top from the Uncooked duct or fitting to create a ¼” flange. Underneath will be the code segment with the International Mechanical Code for that permitted welded duct connections kinds. Numerous kinds of commercial kitchen ventilation  and extraction systems cater to diverse kitchen https://greasetightextractductwor89112.blogdomago.com/35797814/commercial-kitchen-extract-systems-for-dummies