Type ERHK filter elements of filtration grades V, ZN, XN, XXN and A are filter elements with FST filtration technology suitable for the Hankison filter series HF. 

Type ERAC filter elements of filtration grade V (coarse filter) consist of a pleated coarse filter media, filter elements of filtration grades ZN, XN, XXN (coalescing filter) of a pleated depth filter media and a separate drainage media. Thanks to the pleating technology the effective filter surface is increased many times, re-sulting in a higher dirt holding capacity and a longer service life. At the same time flow resistance and there-fore differential pressure, generated by the filter element, are considerably reduced. Due to the separation of the two functional units, filtration and drainage, which are both fundamental for a coalescing filter ele-ment, the function of the remaining layer is guaranteed even if one filter layer breaks. 

To avoid a break-through at an early stage, the pleated depth filter cylinder has at least two or even more layers. In addition, it is provided with a pleated supporting fabric on the inside and outside. Filter elements of filtration grade A (adsorption filter) comprise a special filter media consisting of a loose activated carbon granulate, embedded between two coarse filter layers. In addition, a separate general purpose filter layer (Z) is located towards the outer side, in order to reliably prevent even the finest activated carbon dust from leaving the filter element. 

Using loose activated carbonate granulate results in, for each filter element, an averagely large amount of activated carbon (1.2 kg of activated carbon for each m² of filter surface). This considerably increases the separation capability and the service life. The 3-layer design of the filter media contributes to an adequate thickness of the activated carbon bed and thus to a long contact time between compressed air and activated carbon. 

This results in an extremely low residual oil content. The general purpose filter layer downstream of the activated carbon usually eliminates the need for additional downstream filtration. All media are securely located between the two stainless steel cylinders. In this way, breaking off completely or in parts is impossible. 

All the features mentioned above contribute to a filter element which has a high performance (high separation efficiency) combined with economic efficiency (low differential pressure, long service life) and maximum operating safety (integrated design).