Flange sealing system

1. A sealing element in combination with a flange sealing system including a pair of pipe end flanges of adjoining pipes and a centering ring mounted between the end flanges, the annular sealing element comprising:

an annular solid core structure having an outer circumference wedged within the inner circumference of the centering ring and having first and second faces arranged for sealing engagement with respective ones of the end flanges so as to provide a fluid-tight seal between the end flanges;

wherein one of the inner circumference of the centering ring and the outer circumference of the sealing element has a wedge-shaped cross-section in the form of a convex wedge-shaped edge comprising first and second surface portions that are generally flat and transverse relative to one another so as to project outwardly towards a central apex and so as to define an interior angle between the first and second surface portions which is less than 180 degrees, and another one of the inner circumference of the centering ring and the outer circumference of the sealing element has a concave cross-section in the form of a concave wedge-shaped edge comprising first and second surface portions that are generally flat and transverse relative to one another so as to be inclined inwardly towards a recessed central apex and define an exterior angle between the first and second surface portions which is less than 180 degrees and so as to be shaped to receive the convex wedge-shaped edge therein, and

wherein the interior angle between the first and second surface portions of the convex wedge-shaped edge that are generally flat is greater than the exterior angle between the first and second surface portions of the concave wedge-shaped edge that are generally flat such that the sealing element is readily removable from the centering ring.

2. The combination according to claim 1 wherein:

the centering ring comprises a discontinuous centering ring received between the pipe end flanges surrounding the annular sealing element so as to be arranged to locate the sealing element relative to the fastening of the pipe end flanges;

the discontinuous centering ring is discontinuous in a circumferential direction of the centering ring between two ends of the discontinuous centering ring which are disconnected from one another in a mounted position between the pipe end flanges;

the discontinuous centering ring being flexible relative to the sealing element so as to permit insertion and removal of the sealing element within the centering ring; and

the discontinuous centering ring being resilient such that the sealing element is retained in the discontinuous centering ring solely by tension of the discontinuous centering ring which compresses the outer circumference of the sealing element within the inner circumference of the discontinuous centering ring.

3. The combination according to claim 1 wherein one of the inner circumference of the centering ring and the outer circumference of the sealing element has a wedge-shaped cross-section in the form of a convex wedge-shaped edge comprising first and second surface portions which are generally flat and transverse relative to one another so as to project outwardly towards a central apex and so as to define an interior angle between the first and second surface portions which is less than 180 degrees, and another one of the inner circumference of the centering ring and the outer circumference of the sealing element has a concave cross-section in the form of a concave wedge-shaped edge comprising first and second surface portions which are generally flat and transverse relative to one another so as to be inclined inwardly towards a recessed central apex and define an exterior angle between the first and second surface portions which is less than 180 degrees and so as to be shaped to receive the convex wedge-shaped edge therein, and wherein the interior angle between the first and second surface portions of the convex wedge-shaped edge is greater than the exterior angle between the first and second surface portions of the concave wedge-shaped edge.

4. The combination according to claim 1 wherein the centering ring has a concave wedge-shaped edge on the inner circumference and wherein the sealing element has a convex wedge-shaped edge on the outer circumference thereof.

5. The combination according to claim 4 wherein an outer diameter of the apex of the convex wedge-shaped edge of the sealing element is less than a maximum inner diameter of the centering ring at the apex of the concave wedge-shaped edge and is greater than an minimum inner diameter of the concave wedge-shaped edge of the centering ring adjacent the first and second faces of the sealing element.

6. The combination according to claim 1 further comprising an inner member having an outer circumference comprising a concave wedge-shaped edge, wherein the annular sealing element has an inner circumference comprising a convex wedge-shaped edge, the outer circumference of the inner member being received within the inner circumference of the sealing element such that the convex wedge-shaped edge of the inner circumference of the annular sealing element is received within the concave wedge-shaped edge of the outer circumference of the inner member.

7. The combination according to claim 6 wherein the concave wedge-shaped edge of the outer circumference of the inner member comprises first and second surface portions which are generally flat and transverse relative to one another so as to be inclined inwardly towards a recessed central apex and so as to define an exterior angle between the first and second surface portions which is less than 180 degrees and the convex wedge-shaped edge of the inner circumference of the sealing element comprises first and second surface portions which are generally flat and transverse relative to one another so as to project outwardly towards a central apex and define an interior angle between the first and second surface portions which is less than 180 degrees, and wherein the exterior angle between the first and second surface portions of the concave wedge shaped edge is greater than the interior angle between the first and second surface portions of the convex wedge-shaped edge of the inner circumference of the sealing element.

8. The combination according to claim 6 wherein the inner member comprises a spacer spanning between the sealing element and an inner diameter of the pipes.

9. The combination according to claim 6 wherein the inner member comprises a metal insert having a thickness which is substantially identical to a thickness of the sealing element between the first and second faces thereof.

10. The combination according to claim 6 wherein the inner member comprises a material which is softer than a material of the sealing element, the inner member having a thickness which is greater than a thickness of the sealing element between the first and second faces thereof.

11. The combination according to claim 2 wherein the pair of pipe end flanges are joined to one another by suitable fastening comprising a plurality of flange bolts and wherein the flange sealing system further comprises a mounting ring fixed at the outer circumference of the centering ring diametrically opposite from said two ends of the centering ring so as to be received between the pipe end flanges together with the centering ring, the mounting ring defining a fastener aperture extending therethrough and being located relative to the centering ring so as to receive a respective one of the flange bolts therethrough.

12. The combination according to claim 2 wherein the centering ring is made discontinuous by the provision of a radial cut which forms a gap in the circumference of the ring which is between about 1.0 mm to 2.0 mm wide in the circumferential direction.

13. The combination according to claim 1 in combination with a plurality of centering rings of different size so as to be arranged to fit a wide range of standard pipe and flange sizes, each centering ring comprising an inner circumference into which the outer circumference of said annular sealing element is arranged to be wedged such that the plurality of centering rings are interchangeable with one another.

14. The combination according to claim 1 wherein the first and second faces of the sealing element are each formed with a serrated surface.

15. The combination according to claim 1 wherein the first and second faces of the sealing element are provided with a suitable sealing compound to further improve the fluid-tight seal.

16. The combination according to claim 15 wherein the sealing compound is selected from the group including polytetrafluoroethylene, graphite, a mica based compound, composite non-asbestos fiber, and rubber based laminations.

17. The combination according to claim 1 in further combination with an inner member having an outer circumference comprising a concave wedge-shaped edge, wherein the annular sealing element has an inner circumference comprising a convex wedge-shaped edge, the outer circumference of the inner member being received within the inner circumference of the sealing element such that the convex wedge-shaped edge of the inner circumference of the annular sealing element is received within the concave wedge-shaped edge of the outer circumference of the inner member.

18. The combination according to claim 1 wherein the centering ring comprises a full face centering ring.

19. The combination according to claim 1 wherein the sealing element comprises a solid core sealing element.

20. The combination according to claim 1 wherein the wedge-shaped edge at the outer circumference of the sealing element consists solely of the first and second surface portions which are generally flat and meet at the respective central apex.

21. The combination according to claim 20 wherein the wedge shaped edge at the inner circumference of the centering ring consists solely of the first and second surface portions which are generally flat and meet at the respective central apex.

22. The combination according to claim 1 wherein the outer circumference of the sealing element is wedged within the inner circumference of the centering ring such that the compressive engagement between the sealing element and the centering ring is limited to two annular contact areas which are spaced apart from one another adjacent said first and second faces of the annular solid core structure.

23. The combination according to claim 1 wherein the interior angle between the first and second surface portions of the convex wedge-shaped edge is greater than the exterior angle between the first and second surface portions of the concave wedge-shaped edge by at least 10 degrees.

24. The combination according to claim 1 wherein the interior angle between the first and second surface portions of the convex wedge-shaped edge is greater than the exterior angle between the first and second surface portions of the concave wedge-shaped edge by approximately 30 degrees.

25. The combination according to claim 22 wherein a gap between the first and second surface portions of the convex wedge-shaped edge and the first and second surface portions of the concave wedge-shaped edge varies in dimension between said two annular contact areas.

26. The combination according to claim 1 wherein the first and second surface portions of the convex wedge shaped edge are non-parallel in relation to the first and second surface portions of the concave wedge shaped edge so as to define a resultant gap between the first and second surface portions of the convex wedge shaped edge and the first and second surface portions of the concave wedge shaped edge that varies in dimension.