Thanks to strong R&D activities in the ﬁeld of tank optimization and, in particular, degassing of hydraulic fluids, engineers at Hydac have developed a new ﬁlter line. The products include a refined housing design and flow based on an in-to-out concept. In-to-out filtration helps ensure low outlet velocity and minimizes turbulence in the tank. Integrated de-aeration windows in the filter assembly help guide the flow and coalesce air bubbles.
The filters — with its special degassing capabilities — reduce the amount of air entrained in oil. It also lets system designers signiﬁcantly reduce the tank size. That means both, OEM and operator save costs due to less material use, smaller oil volume and lower weight.
The products are available in several different designs that are integrated in the tank. They include: RKT Return Line Kit – Top (flow from the top of a tank) and RKB Return Line Kit – Bottom (flow from bottom); as well as filter assemblies RFT Return Line Filter – Top (flow from top) and RF Return Line Filter – Bottom (flow from bottom).
For example, the RKT handles flows up to 1,200 l/min, and pressures to 10 bar. This filter system provides an economical solution for full-flow return line filtration for small and large flows, according to Hydac. The filter mounts in an intermediate chamber in the top part of the tank. This integrates the filter into the tank, so most any design is possible for the return port connections, and several filters can be used without splitting up the return lines.
Optimal flow conditions in the chamber provide effective magnetic prefiltration and long filter service lives. Housings designs meet international regulations and consist of a housing tube, filter cover and an element location spigot. For ease of maintenance, the filter element can be removed from the top.
One optional feature for all versions is Quality Protection (both mechanical and intelligent), which does not permit a hydraulic system to operate with a competitive element installed. Quality Protection is implemented in combination with a special smart Hydac clogging indicator that recognizes and confirms the installation of an original Hydac element.
Advantages of the new return-filter products include longer oil service life thanks to active degassing and in-to-out filtration; high reliability, because the seal is replaced with each element change; lower pressure drop thanks to Hydac’s Helios high-efficiency pleat geometry; and lower service costs due to smaller tank size and lower oil volume.
The filters are compatible with standard hydraulic fluids (ISO 2943) as well as various biodegradable hydraulic fluids, lubrication oils, and compressor oils.