The present invention relates to back-flushable filters, namely filters wherein a back-flushing of the filter body is effected by applying pressurized fluid to the downsteam face of the filter body. The invention is particularly useful with respect to the back-flushable filter described in my U.S. Pat. No. 4,806,217, and is therefore described below with respect to that type of filter construction.
My U.S. Pat. No. 4,806,217 describes a filter device comprising a tube partially enclosed by a housing defining an internal chamber with the tube, and having a filter body within the internal chamber. In the normal position of the housing, the inlet receiving the pressurized fluid is applied to the upstream face of the filter body so that the filter operates in the conventional manner to separate particles from the fluid being filtered; but when the housing is moved in the axial direction, the inlet is applied to the downstream face of the filter body to thereby back-flush it in order to clean the filter body.