Composition
The flange insulation set Guardian Basic IE uses phenolic material as an sealing and insulating part. The gasket can also be covered with rubber to reduce the permeability in the style IER. The washers and the tubes can also be made by phenolic material but the use of GRE G10 (FR4) is strongly recommended. The lower permeability of this material is in fact a guarantee of stability over time of the system sealing and insulation.