Grease duct joints are held collectively via shaped V clamps and sealed with 3M Fire Barrier 2000+. Reduction in cross-part: The internal dimensions (width and height for rectangular ducts, diameter for round ducts) with the smoke extracting ductwork shall not lessen by over ten% in the test. Promat calcium silicate https://grease-tight-extract-duct58900.blogginaway.com/37761403/not-known-factual-statements-about-fire-resisting-ductwork-insulation