For failsafe operation of hydraulic systems, optimum filtration of the fluid is essential. 80 % of all failures can be traced back to contaminated fluid. The responsible particles are not visible to the naked eye. New filter media of the fifth generation by Rexroth reliably retain these contaminations. At the same time, they lower the operating costs thanks to a significantly increased service life of the filter elements. In addition, this is the first time a manufacturer has equipped all filter elements in standard sizes with an electrical conductive fleece filter medium by default. In this way, the risk of electric discharges in connection with zinc- and ash-free hydraulic oils is reduced.
Based on the extensive application experience as a world-leading manufacturer of hydraulic systems and with the help of recent insights of materials science and comprehensive flow analyses, Rexroth has developed completely new filter materials. The fifth generation is used in all Rexroth filter elements of all marketable sizes. The ideally coordinated filter systems made of glass fiber achieve high retention rates which is the measure for filter efficiency. These rates indicate at which ratio the filter element retains particles of a defined size. The ß-values of the new filter material according to ISO 16889 are far over 200 depending on the filter rating. In this way, users achieve very good filtering results and increase their system availability thanks to optimally cleaned hydraulic fluids.
Electrical conductive fleece in series
The newly developed filter elements are equipped with an additional conductive fleece filter medium by default. It provides for a charge exchange between oil and filter material and thereby reduces the risk of electrostatic charge and discharge in the filter. End users of hydraulic systems increasingly use zinc- and ash-free oils. These hydraulic media usually have reduced conductivity. If it is less than 300 picosiemens per meter, the danger of electrostatic discharge increases. Discharge processes are often visible in the form of lightning discharges or can be identified by a sizzling noise. Each discharge can burn tiny amounts of oil and reduce the service life of the medium. Discharges can also burn holes in the filter layers. This reduces the retention rate and increases the danger of particles passing through the filter and causing damage in the system.
Only two instead of three filter element exchanges
In addition to the high filtration efficiency, the new material also increases the dirt holding capacity. Compared to the previous generation, the new filter elements absorb up to 50 percent more particles and thereby prolong the service life by the same value under constant operating conditions. Over the operating time, three filter exchanges were required up to now. The new generation reduces the effort to two exchanges. This means that users save costs for filter elements, their disposal and the associated labor.
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