The chimney systems for industrial kitchens are elements with a high risk of fire. There is also a risk of fire in the chimney system due to the fats which settle down in the system.
This is why the RITE demands that the system is fire resistant for at least 30 minutes, which in this case means the inner pipe.
In this regard Jeremias is the only manufacturer of chimneys and ventilation systems that has tested and certificated a system with this specification consisting of rock wool insulation. In this way we avoid any type of hot spots on the outer wall in case of fire, as the rock wool doesn't allow any metallic connection between the inner and outer wall.
Metallic modular pipe with fire resistance EI30 for double wall isolated air extraction made of stainless steel.