AUTOMATIC BACKFLUSH FILTER
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