Filter incorporating two distinct filtering stacks

In a filter constituted by:

• a filter body comprising a plurality of distinct chambers isolated from one another,
• a main stack of filtering elements contained in one of said chambers, called main chamber,
• a secondary stack of filtering elements contained in another of said chambers, called secondary chamber, each of the filtering elements of the main and secondary stacks having a recessed centre and a cylindrical side, comprising a plurality of sections isolated from one another and being provided on its outer and inner radial circumferences with orifices for communication of each of its sections with said circumferences,
• a shut-off distribution valve which is adjusted to said cylindrical side, which is mounted to rotate about the axis of the cylindrical side, and which comprises one main enclosure capable, in a first position of the distribution valve, of isolating a first section of any one filtering element of the main stack from the other sections of said filtering element and of communicating with said first section via the orifice for communication of said first section, and one secondary enclosure capable, in a second position of the distribution valve of isolating a first section of any one filtering element of the secondary stack from the other sections of said filtering element and of communicating with said first section via the orifice for the communication of said first section, and wherein
• a port, with which the distribution valve is provided, connects the main and secondary enclosures.