Filter cartridge

1. A filter cartridge ( 60 , 160 ) comprising a filter wall ( 63 , 163 ) having a tubular shape and at least a support plate ( 61 , 161 ) fixed to an end of the filter wall ( 63 , 163 ), wherein a by-pass conduit ( 66 , 166 ) is fashioned in the support plate ( 61 , 161 ), which by-pass conduit ( 66 , 166 ) is designed to place an internal volume ( 64 , 164 ) delimited by the filter wall ( 63 , 163 ) in communication with outside, which by-pass conduit ( 66 , 166 ) is intercepted by a valve ( 70 , 170 ) which is associated to the support plate ( 61 , 161 ) in an out-of-centre position with respect to a longitudinal axis (A, A 2 ) of the filter wall ( 63 , 163 ), wherein the valve ( 70 , 170 ) comprises an internally-hollow valve body ( 71 , 171 ), which is provided with a hole ( 72 , 172 ) suitable for setting the bypass conduit ( 66 , 166 ) in communication with the internal cavity of the valve body ( 71 , 171 ), an obturator ( 73 , 174 ) housed in the internal cavity of the valve body ( 71 , 171 ), and an elastically-acting element ( 75 , 180 ) suitable for pressing the obturator ( 73 , 174 ) against a valve seating ( 74 , 179 ) such as to close the hole ( 72 , 172 ), the valve ( 70 , 170 ) being housed internally of a blind seating ( 67 , 167 ) afforded in the support plate ( 61 , 161 ), wherein said blind seating ( 67 , 167 ) opens on an external surface of the support plate ( 61 , 161 ) opposite to the filter wall.

2. The filter cartridge ( 60 , 160 ) of claim 1 , wherein the valve ( 70 , 170 ) is aligned with a lateral wall of the filter wall ( 63 , 163 ).

3. The filter cartridge ( 60 , 160 ) of claim 1 , wherein the valve ( 70 , 170 ) is unremovably housed internally of said seating ( 67 , 167 ).

4. The filter cartridge ( 60 , 160 ) of claim 1 , wherein the valve ( 70 , 170 ) is removably housed in the seating ( 67 , 167 ).

5. The filter cartridge ( 60 , 160 ) of claim 1 , wherein the valve ( 70 , 170 ) is configured such as to open the by-pass conduit ( 66 , 166 ) following a pressure increase in the internal volume ( 64 , 164 ) delimited by the filter wall ( 63 , 163 ).

6. The filter cartridge ( 60 ) of claim 1 , wherein the valve ( 70 ) comprises a spherical obturator ( 73 ) and at least an elastic plate ( 76 ) configured to maintain the obturator ( 73 ) pressed against the valve seating ( 74 ), such as to close the by-pass conduit ( 66 ).

7. The filter cartridge ( 60 ) of claim 6 , wherein the valve body ( 71 ) is cylindrical.

8. A filter cartridge ( 161 ) according to claim 1 , further comprising a heat-sensitive element ( 181 ) configured such as to occlude the bypass conduit ( 166 ) when the temperature of the heat-sensitive element ( 181 ) exceeds a predetermined threshold value.

9. The filter cartridge ( 160 ) of claim 8 , whereom the heat-sensitive element ( 181 ) is associated to the valve ( 170 ).

10. The filter cartridge ( 160 ) of claim 9 , wherein the heat-sensitive element ( 181 ) is an elastically-acting element suitable for pressing the obturator ( 174 ) against the valve seating ( 179 ), which element has an elastic constant that grows following an increase in temperature.

11. The filter cartridge ( 160 ) of claim 9 , wherein the heat-sensitive element ( 181 ) is predisposed such that, following an increase in temperature, it is configured to move from an initial configuration, in which it is separated from the obturator ( 174 ) leaving the obturator ( 174 ) free to distance from the valve seating ( 179 ), in contrast with the elastically-acting element ( 180 ), to a final configuration, in which it is in contact with the obturator ( 174 ), blocking the obturator ( 174 ) against the valve seating ( 179 ).

12. The filter cartridge ( 160 ) of claim 8 , wherein the heat-sensitive element ( 181 ) is predisposed such that following an increase in temperature, it is configured to move from an initial configuration, in which it leaves the bypass conduit ( 166 ) open, to a final configuration, in which it obstructs the bypass conduit ( 166 ).

13. A filter ( 10 , 110 ) comprising an external casing ( 20 , 120 ) provided with an inlet ( 23 , 123 ) for a fluid to be filtered and an outlet ( 24 , 124 ) for filtered fluid, and a filter cartridge ( 60 , 160 ) as in claim 1 , configured to divide an internal volume of the casing ( 20 , 120 ) into a first chamber ( 64 , 164 ) communicating with the inlet ( 23 , 123 ) and a second chamber ( 65 , 165 ) communicating with the outlet ( 24 , 124 ).

14. The filter ( 10 , 110 ) of claim 13 , wherein the filter cartridge ( 60 , 160 ) is positioned such that the first chamber is at least partly defined by the internal volume ( 64 , 164 ) delimited by the filter wall ( 63 , 163 ), and in that the by-pass conduit ( 66 , 166 ) is configured to place the internal volume ( 64 , 164 ) in communication with the second chamber ( 65 , 165 ).

15. The filter ( 10 , 110 ) of claim 14 , whereinn the second chamber ( 65 , 165 ) communicates with the outlet ( 24 , 124 ) via a second filter wall ( 55 , 155 ) having a greater porosity than the filter wall ( 63 , 163 ) of the filter cartridge ( 60 , 160 ).