The ProFlapIII of Keller has succeeded in the certification according the newest standard EN 16447.
Since the beginning of july 2017 is the ProFlapII available which makes it the first ATEX certified non-return valve with this certificate on the market.
The ATEX certified non-return valve ProFlapIII is designed to shut off aspiration ducting of dust extraction filters when a dust explosion occurs so that the overpressure and all the flames are stopped.
The ProFlapIII is not only suitable for organic dust eg. wood, polyethylen, flour, … but can also be used for metal dust.
Temperature of a dust explosion of metal dust like aluminium or zinc raises much higher.
To make the ProFlapIII suitable for metal dust the MESG - maximum experimental safe gap – was decreased to only 1.3mm.
Also the design of the ProFlapIII is further optimised to minize the pressure drop.
For the ProFlapIII, different options are available such as a wear sensor and a measuring of the opening of the flap. The opening of the flap is a measure fort he airflow. The measuring of the opening angle of the flap is done in a redundant way so that it is compliant with performance level d according to EN 13849. Because an ATEX dust extraction has often a safety function for the production process, this is a valuable solution which eliminates extra air flow measuring devices.
Other advantages of the ProFlapIII are e.g. that it is a passive protection which is much cheaper than active protection systems. Also can the ProFlapIII be used for dust concentrations in the aspiration ducts which are higher than the lower explosion limit LEL.
For the American market the ProFlapIII is als certified according the more severe standard NFPA 69.