In order to avoid spark strikes that lead to ignition of the Ex atmosphere, only specified material pairings are permitted for ATEX products in accordance with DIN EN 14986. This implementation is shown, for example, in copper/brass rings for the inlet nozzle when using fan wheels.
In general, fan wheels must be able to withstand a test run at 1.15 times the operating speed for at least 60s. The potential deformation of the fan wheel must not result in an ignition hazard that could arise when the fan wheel comes into contact with the housing. Exceptions are fan wheel designs whose maximum stresses are less than 2/3 of the material yield strength.
Clamping bush systems are not permitted for mounting the fan wheels. The shaft-hub connection must consist of a stable, one-piece fixed hub.
Our engineering department will be pleased to support you in your conceptual design and in checking whether the punker ventilation components fit your specifications so that they can be used in an Ex atmosphere.