Flanged valves require a gasket between the duct and valve flanges, with the addition of nuts and bolts as flange fasteners. Ensure that the metal straps support both sides of the valve weight and the duct work. For correct hardware, mounting, sealing and installation requirements, consult local building codes.
Note: Gasket, nuts, and bolts are field supplied. They do not come with the valve.
Figure 1. Mounting a flanged valve