Positive hub seal

1. A valve comprising:

a valve body defining a shaft bore therethrough, an axis of the shaft bore defining a vertical axis;

a valve shaft positioned within and configured to rotate within the valve body;

a valve disc coupled to the valve shaft and positioned within the valve body, the valve disc configured to rotate within the valve body between an open position and a closed position, the valve disc defining an axial end; and

a valve seat positioned within the valve body, the valve seat comprising an outer surface in contact with the valve body and an inner surface in contact with the valve disc, the inner surface of the valve seat defining a sealing ridge extending radially inward with respect to the vertical axis, the sealing ridge having an annular shape about the valve shaft, the sealing ridge concentric with the valve shaft, the axial end of the valve disc defining a surface facing the inner surface of the valve seat and in contact with the inner surface of the valve seat,

each of an entirety of the surface of the valve disc and an entirety of the inner surface of the valve seat that is in contact with the surface of the valve disc except for the sealing ridge being perpendicular to the vertical axis of the valve body.

2. The valve of claim 1 , wherein the sealing ridge is compressed by the axial end of the valve disc, the axial end of the valve disc defined with respect to the vertical axis.

3. The valve of claim 1 , wherein interference between the sealing ridge in a natural position and the valve disc is equal to a maximum height of the sealing ridge.

4. The valve of claim 1 , wherein the maximum height of the sealing ridge is between 0.005 inches and 0.015 inches.

5. The valve of claim 4 , wherein the maximum height of the sealing ridge is about 0.010 inches.

6. The valve of claim 1 , wherein the sealing ridge defines a radiused peak surface.

7. The valve of claim 1 , wherein:

the sealing ridge is a first sealing ridge;

the inner surface of the valve seat defines a second sealing ridge extending radially inward, the second sealing ridge having an annular shape about the valve shaft, the second sealing ridge concentric with the valve shaft; and

the first sealing ridge is offset radially with respect to the vertical axis from the second sealing ridge by a ridge separation distance.

8. The valve of claim 1 , wherein the valve seat further comprises a flange extending axially along the vertical axis from the outer surface into a space defined between the shaft bore and the valve shaft.

9. A valve seat comprising:

an outer surface; and

an inner surface opposite from the outer surface, the inner surface defining a valve seat bore extending through the valve seat, the valve seat bore defining a valve seat bore axis, the inner surface of the valve seat defining a sealing ridge, the sealing ridge extending radially inward and defining a radiused peak surface, the sealing ridge having an annular shape about the valve seat bore, the sealing ridge concentric with the valve seat bore, an entirety of the inner surface of the valve seat that is configured to be in contact with a surface of an axial end of a valve disc except for the sealing ridge being perpendicular to the valve seat bore axis.

10. The valve seat of claim 9 , wherein:

the sealing ridge is a first sealing ridge;

the inner surface of the valve seat defines a second sealing ridge extending radially inward, the second sealing ridge having an annular shape about the valve seat bore; and

the second sealing ridge of the two sealing ridges is offset radially with respect to the vertical axis from a first sealing ridge by a ridge separation distance.

11. The valve seat of claim 10 , wherein the ridge separation distance is equal to a base width of a one of the first sealing ridge and the second sealing ridge.

12. The valve seat of claim 10 , wherein the valve seat further comprises a radiused valley surface between the first sealing ridge and the second sealing ridge.

13. The valve seat of claim 9 , wherein a peak of the sealing ridge is offset in a radial direction from an edge of the valve seat bore by a distance greater than half a width of the sealing ridge.

14. The valve seat of claim 9 , wherein the sealing ridge is concentric with the valve seat bore of the valve seat.

15. The valve seat of claim 9 , wherein the maximum height of the sealing ridge is between 0.005 inches and 0.015 inches.

16. A method of using a valve, the method comprising:

rotating a valve disc of the valve, the valve comprising:

a valve body defining a shaft bore and an interior cavity, an axis of the shaft bore defining a vertical axis;

a valve shaft positioned within and configured to rotate within the interior cavity of the valve body;

the valve disc coupled to the valve shaft and defining an axial end, the axial end of the valve disc defined with respect to the vertical axis; and

a valve seat positioned within the valve body, the valve seat comprising an outer surface in contact with the valve body and an inner surface in contact with the valve disc, the inner surface of the valve seat defining a sealing ridge extending radially inward with respect to the vertical axis, the sealing ridge having an annular shape about the valve shaft, the sealing ridge concentric with the valve shaft, the axial end of the valve disc defining a surface facing the inner surface of the valve seat and in contact with the inner surface of the valve seat, each of an entirety of the surface of the valve disc and an entirety of the inner surface of the valve seat that is in contact with the surface of the valve disc except for the sealing ridge being perpendicular to the vertical axis of the valve body;

contacting the sealing ridge of the valve seat with the axial end of the valve disc; and

compressing the sealing ridge such that a maximum height of the sealing ridge is reduced.

17. The method of claim 16 , wherein compressing the sealing ridge comprises compressing the sealing ridge a distance equal to the maximum height of the sealing ridge.

18. The method of claim 16 , wherein rotating the valve disc of the valve comprises sliding the axial end of the valve disc along a peak of the sealing ridge in a circular path about the vertical axis.

19. The method of claim 16 , wherein the sealing ridge in a natural position defines a radiused peak surface.

20. The method of claim 16 , wherein compressing the sealing ridge comprises sealing around the shaft bore of the valve to prevent fluid flow past the sealing ridge from the interior cavity of the valve to the shaft bore of the valve, and wherein rotating the valve disc of the valve further comprises rotating the valve shaft within the shaft bore and within a flange of the valve seat, the flange extending axially along the vertical axis from the outer surface of the valve seat into a space defined between the shaft bore and the valve shaft.