Parallel slide gate valves and related methods

1. A parallel slide gate valve, comprising:

a valve stem coupled to an obturator and configured to translate the obturator relative to a valve body between an open position and a closed position;

the valve body comprising an interior surface, wherein a portion of the interior surface defines at least one recessed groove within the surface, the recessed groove being substantially rectangular and having a length and at least one width with the length oriented parallel to the valve stem and substantially perpendicular to a direction of flow along a fluid flow path through the valve body, wherein the at least one recessed groove has a first width at a first end proximate to the fluid flow path and a second width at a second end distal from the fluid flow path, the second width smaller than the first width; and

the obturator comprising a first generally planar member, a second generally planar member, and a biasing member between the first generally planar member and the second generally planar member, wherein the first generally planar member is oriented substantially parallel to the second generally planar member, wherein the obturator comprises at least one guide rail comprising a portion of each of the first generally planar member and the second generally planar member, the at least one guide rail protruding into the at least one recessed groove in the valve body, and configured to move within the at least one recessed groove when the obturator translates from the closed position to the open position; and

wherein the obturator is configured to translate from the first end of the at least one groove toward the second end of the at least one groove as the obturator moves from the closed position to the open position, wherein the obturator positively seals the valve against the valve body in the closed position by action of the biasing member of fluid pressure.

2. The parallel slide gate valve of claim 1 , wherein the first generally planar member and the second generally planar member of the obturator are maintained within a selected distance from one another by the at least one recessed groove.

3. The parallel slide gate valve of claim 1 , wherein the at least one recessed groove is configured to cause a distance between the first generally planar member and the second generally planar member to decrease as the obturator moves from the closed position to the open position.

4. The parallel slide gate valve of claim 1 , wherein the first generally planar member and the second generally planar member of the obturator are maintained within a selected distance from one another without a bracket coupled to the obturator.

5. The parallel slide gate valve of claim 1 , further comprising at least one valve seat having a sealing surface configured to abut against a surface of the obturator and form a fluid seal between the obturator and the valve body when the obturator is in the closed position.

6. The parallel slide gate valve of claim 5 , wherein at least one valve seat is welded to the valve body.

7. The parallel slide gate valve of claim 5 , wherein the at least one valve seat comprises a hardfacing material.

8. The parallel slide gate valve of claim 1 , further comprising a handle coupled to the valve stem.

9. The parallel slide gate valve of claim 1 , wherein at least one recessed groove comprises two grooves configured to retain opposing surfaces of the obturator when the obturator is in the open position.

10. The parallel slide gate valve of claim 1 , wherein the obturator is configured to leave the at least one recessed groove as the valve stem moves the obturator from the open position to the closed position.

11. A method of operating a parallel slide gate valve comprising a valve body and an obturator coupled to a valve stem within the valve body, the method comprising:

passing a fluid through the valve body while the obturator is in an open position, wherein the valve body comprises an interior surface, a portion of the interior surface defining at least one recessed groove within the surface, the recessed groove being substantially rectangular and having a length and at least one width with the length oriented parallel to the valve stem and substantially perpendicular to a direction of flow along a fluid flow path through the valve body, wherein the at least one recessed groove has a first width at a first end proximate to the fluid flow path and a second width at a second end distal from the fluid flow path, the second width smaller than the first width;

translating the obturator perpendicular to the direction of flow of the fluid from the second end of the at least one groove toward the first end of the at least one groove, wherein the obturator comprises a first generally planar member, a second generally planar member, and a biasing member between the first generally planar member and the second generally planar member, wherein the first generally planar member is oriented substantially parallel to the second generally planar member, and wherein the obturator further comprises at least one guide rail comprising a portion of each of the first generally planar member and the second generally planar member, protruding into the at least one recessed groove in the valve body, and configured to move within the at least one recessed groove when the obturator translates from a closed position to an open position; and

forming a seal between a surface of the obturator and the valve body by action of the biasing member or fluid pressure to terminate flow through the valve body.

12. The method of claim 11 , wherein translating the obturator perpendicular to the direction of flow of the fluid from the second end of the at least one recessed groove toward the first end of the at least one groove comprises increasing a thickness of the obturator.

13. The method of claim 11 , further comprising translating the obturator perpendicular to the direction of flow of the fluid from the first end of the at least one recessed groove toward the second end of the at least one groove to restart fluid flow through the valve body.

14. The method of claim 13 , wherein translating the obturator perpendicular to the direction of flow of the fluid from the first end of the at least one recessed groove toward the second end of the at least one groove comprises decreasing a thickness of the obturator.

15. The method of claim 13 , further comprising breaking the seal between the surface of the obturator and the valve body.