Filter cartridge for liquid filtration; assembly; and, methods

1. A liquid filter cartridge comprising:

(a) first and second, opposite, end caps;

(i) the first end cap having a first central liquid flow aperture therethrough; and,

(b) an extension of filter media secured to, and extending between, the first and second end caps;

(i) the extension of filter media comprising pleated media defining an open central volume in fluid flow communication with the first central aperture and having a pleat inner diameter and a pleat outer diameter; and,

(ii) the media comprising a total of at least 20 pleats;

(c) a first seal arrangement comprising a first radially directed seal; and,

(d) the first seal arrangement being positioned to provide a larger seal diameter (D s A) when sealing than a diameter of the first central aperture;

(i) D s A being within the range of 0.95-1.05 D b A inclusive, wherein D b A is a calculated seal diameter at which no net surface axial force on the first end cap toward or away from the second end cap due to liquid pressures against the opposite surfaces of the first end cap, in use, results, with D b A calculated assuming that any pressure drop across the media occurs at the media center line and is a step function and that each media pleat assumes a triangular shape the same as each other pleat.

2. A liquid filter cartridge according to claim 1 including:

(a) a first seal support projecting outwardly from the first end cap;

(i) the first radially directed seal being positioned on the first seal support.

3. A liquid filter cartridge according to claim 2 wherein:

(a) the first radially directed seal comprises a radially outwardly directed seal.

4. A liquid filter cartridge according to claim 3 wherein:

(a) the first radially directed seal comprises on an o-ring seal.

5. A liquid filter cartridge according to claim 4 wherein:

(a) the liquid filter cartridge has an axial load coreless construction.

6. A liquid filter cartridge according to claim 5 wherein:

(a) the liquid filter cartridge has an axial load outer liner free construction.

7. A liquid filter cartridge according to claim 3 wherein:

(a) the liquid filter cartridge has an axial load outer liner free construction.

8. A liquid filter cartridge according to claim 3 wherein:

(a) the liquid filter cartridge has an axial load coreless construction.

9. A liquid filter cartridge according to claim 2 wherein:

(a) the first radially directed seal comprises on an o-ring seal.

10. A liquid filter cartridge according to claim 1 wherein:

(a) the first radially directed seal comprises an o-ring seal.

11. A liquid filter cartridge according to claim 1 wherein:

(a) the first radially directed seal comprises a radially outwardly directed seal.

12. A liquid filter cartridge according to claim 2 wherein:

(a) the first radially directed seal comprises a radially inwardly directed seal.

13. A liquid filter cartridge according to claim 12 wherein:

(a) the first radially directed seal comprises on an o-ring seal.

14. A liquid filter cartridge according to claim 13 wherein:

(a) the liquid filter cartridge has an axial load coreless construction.

15. A liquid filter cartridge according to claim 14 wherein:

(a) the liquid filter cartridge has an axial load outer liner free construction.

16. A liquid filter cartridge according to claim 1 wherein:

(a) the second end cap is a closed end cap.

17. A liquid filter cartridge according to claim 1 wherein:

(a) the second end cap is an open end cap.

18. A liquid filter cartridge according to claim 17 wherein:

(a) the second end cap includes a second seal arrangement comprising a radially directed seal thereon.

19. A liquid filter cartridge according to claim 18 wherein:

(a) the second end cap includes a radially outwardly directed seal thereon.

20. A liquid filter cartridge according to claim 18 wherein:

(a) the second end cap includes a radially inwardly directed seal thereon.

21. A liquid filter cartridge according to claim 18 wherein:

(a) a second seal support is positioned on the second end cap;

(i) the radially directed seal being positioned on the second seal support.

22. A liquid filter cartridge according to claim 21 wherein:

(a) the second seal arrangement is positioned to provide a larger seal diameter (D s B) with structure in a filter assembly when sealing than a diameter of the second central aperture;

(i) D s B being within the range of 0.85-1.15 D b B, inclusive, wherein: D b B is a calculated seal diameter at which no net surface axial force on the second end cap toward or away from the first end cap due to liquid pressure against the opposite surfaces of the second end cap results, with D b B calculated assuming the any pressure drop across the media occurs at the media center line and is a step function and that each media pleat assumes a triangular shape the same as each other pleat.

23. A liquid filter cartridge according to claim 22 wherein:

(a) D s B is within the range of 0.95-1.05 D b B, inclusive.

24. A liquid filter cartridge according to claim 22 wherein:

(a) D s B is within the range of 0.90-1.10 D b B, inclusive.

25. A liquid filter cartridge according to claim 18 wherein:

(a) the second seal arrangement is positioned to provide a larger seal diameter (D s B) with structure in a filter assembly when sealing than a diameter of the second central aperture;

(i) D s B being within the range of 0.85-1.15 D b B, inclusive, wherein: D b B is a calculated seal diameter at which no net surface axial force on the second end cap toward or away from the first end cap due to liquid pressure against the opposite surfaces of the second end cap results, with D b B calculated assuming the any pressurem drop across the media occurs at the media center line and is a step function and that each media pleat assumes a triangular shape the same as each other pleat.

26. A liquid filter assembly comprising:

(a) a filter housing;

(i) the filter housing being threaded, for mounting on a filter head, in use; and,

(b) a liquid filter cartridge positioned within the housing, the liquid filter cartridge comprising:

(i) first and second, opposite, end caps;

(A) the first end cap having a first central liquid flow aperture therethrough; and,

(ii) an extension of filter media secured to, and extending between, the first and second end caps;

(A) the extension of filter media comprising pleated media defining an open central volume in fluid flow communication with the first central aperture and having a pleat inner diameter and a pleat outer diameter; and,

(B) the media comprising a total of at least 20 pleats;

(iii) a first cartridge seal arrangement comprising a first radially directed seal; and,

(iv) the first cartridge seal arrangement being positioned to provide a larger seal diameter (D s A), when sealing, than a diameter of the first central aperture;

(A) D s A being within the range of 0.95-1.05 D b A inclusive, wherein D b A is a calculated seal diameter at which no net surface axial force on the first end cap toward or away from the second end cap due to liquid pressures against the opposite surfaces of the first end cap, in use, results, with D b A calculated assuming the any pressure drop across the media occurs at the media center line and is a step function and that each media pleat assumes a triangular shape the same as each other pleat.

27. A liquid filter assembly according to claim 26 including:

(a) a filter head including an inlet channel; and, an outlet channel;

(i) the outlet channel being defined by a liquid flow portion of the filter head; and,

(b) the filter housing being secured to the filter head with the first cartridge seal arrangement sealed to the filter head.

28. A liquid filter cartridge according to claim 22 wherein:

(a) D s B is within the range of 0.92-1.05 D b B, inclusive.