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Constantly increasing levels of performance and the growing degree of automation in hydraulically operated systems require all components to function perfectly. It is therefore vital, for example, to ensure that control valves work accurately. This has been achieved, among others, by reducing the fi t tolerances between housing and piston. To prevent that impurities in the hydraulic fluid as a result of this development cause functions to fail in a system an effective filter has been developed: The fully automatic backflush filter. This filter is used as pressure filter in the main flow and in a hydraulic system has the function of filtering and removing the contaminants of a hydraulic fluid. These contaminants mainly occur in the form of metallic abrasions, lacquer, rubbed off seal parts, dust, and scales. When no backflush filters are installed these dirt particles are taken to all points of a hydraulic system and can thus impair the functional reliability of the system. The backflush filter consists of the filter housing, the filter elements, and the control components. The standard connection is a flange with nominal width DN51SSO which can be adapted to the individual requirements by means of different fittings. 

Contaminated pressure fluid enters the filter housing at the inlet. It flows through the filter elements from the outside in. Dirt particles which are larger than the pore size of the filter element are trapped. The filtered fluid leaves the housing at the outlet. The contaminated filtrate is generally removed via separate lines. The pilot valves are supplied with the backflushed hydraulic fluid internally. 

Pressure sensors at the filter inlet and outlet measure the differential pressure. The latter is an indicator of the degree of contamination: Increased contamination of the filter causes the differential pressure to rise. If the pressure difference exceeds a defined value the filter element is automatically cleaned removing dirt particles from the filter element. Based on preset parameters, the backflush process can be triggered by differential pressure, time or a combination of the two. The lower the differential pressure value set at the filter the more of-ten will backflushing be performed. This essentially increases the life of the filter elements. A signal transmitted from the control unit activates the pilot valve which in turn triggers the back flush process: The internal valves are reversed and the pressure fluid flows through the filter element in the opposite direction for approx. 2 to 3 seconds. The dirt particles are removed from the filter and drained via the leakage port. While one filter element is cleaned by backflushing the other element continues filtration to permit trouble free operation. 

  • Pressure-resistant  backflush filter, nominal  pressure up to 350 bar
  • Fully automatic filter dewatering
  • differential pressure or time control, or a combination of the two
  • Electrohydrauic control
  • Simple operation thanks to standard control units
  • Made of surgical steel
  • Suitable for all fluids
  • Extended maintenance intervals

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