Patent Application
20150060715
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
In certain applications, a structure (e.g., a wireline or tubing) may obstruct closure of a valve, such as a gate valve. Under certain conditions, it may be desirable to cut the wireline or tubing to enable closure of the valve while retaining the valve's sealing integrity over an extended period of use.
Various features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying figures in which like characters represent like parts throughout the figures, wherein:
One or more specific embodiments of the present invention will be described below. These described embodiments are only exemplary of the present invention. Additionally, in an effort to provide a concise description of these exemplary embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
The following disclosure relates to an exemplary improved seal ring that has a seat ring supported by a seat holder. That seat ring may be formed from a hard, corrosion resistant material, such as metals, metal alloys, ceramics, ceramic metals (i.e., cermets), or any combination thereof, for example. Particular examples of a hard, corrosion resistant material are Stellite™ (e.g., cobalt-based alloys and/or cobalt-chromium alloys), tungsten carbide, stainless steel, carbides, nitrides, or other material designed for corrosion resistance and/or wear resistance. Moreover, the Stellite™ may include cobalt, nickel, iron, aluminum, boron, carbon, chromium, manganese, molybdenum, phosphorus, sulfur, silicon, titanium, or any combination thereof.
The seat ring may be retained within the seat holder by a seal, such as an O-ring, a shrink fit material and/or method, a snap-fit, threads, an interference fit, or other retaining material and/or method. In certain embodiments, the seat ring may be formed from an existing seal ring. For example, an existing seal ring (e.g., a previously used seal ring) may be machined or modified to form the seat holder mentioned above. Thereafter, the seat holder may be fitted with the seat ring, and the seat ring may be retained within the seat holder by a sealing material, a shrink fit material and/or method, a snap-fit, an interference fit, or other retaining material and/or method. In this manner, existing or previously used (e.g., previously used in the field) seal rings may be re-used, refurbished, recycled, or otherwise improved, thereby reducing costs associated with manufacturing and/or maintaining gate valves.
In the illustrated embodiment, the gate valve 10 includes an actuator 14. The actuator 14 may be coupled to a top portion of a valve body 18 via a bonnet 20, or the actuator 14 can be directly coupled to the valve body 18. The body 18 may be constructed of cast iron, ductile iron, cast carbon steel, gun metal, stainless steel, alloy steels, corrosion resistant alloys, and/or forged steels. The gate valve 10 includes a gate 22 disposed within a cavity 24 of the body 18. As will be appreciated, the gate 22 is configured to move (e.g., axially translate) between an open position and a closed position within the cavity 24. As illustrated, the gate 22 is disposed in the open position. In certain embodiments, the gate 22 has a rectangular cross-sectional profile. The body 18 of the gate valve 10 includes an inlet 26 and an outlet 28 configured for a flow of a fluid through a bore 30 of the body 18 into a passage 32 of the gate valve 10. In certain embodiments, the outlet 28 may act as an inlet allowing fluid flow into the passage 32 from either side of the gate valve 10. For example, in some embodiments, the inlet 26 may act as an outlet and the outlet 28 may act as an inlet.
Additionally, as mentioned above, the gate valve 10 may be configured to shear a wireline, coil tubing, or other tubular member. In the illustrated embodiment, a wireline 34 extends through the bore 30 and the passage 32 of the body 18 of the gate valve 10. When the gate 22 of the gate valve 10 moves (e.g., axially translates) from an opened position to a closed position, the gate 22 shears the wireline 34, thus allowing the gate 22 to close without removing the obstruction, here the wireline 34.
In the illustrated gate valve 10, the actuator 14 provides the motive force to open and close the valve 10. In particular, the actuator 14 applies a force (e.g., a linear axial force) to a stem 36 coupling the gate 22 to the actuator 14. In this manner, the gate 22 moves (e.g., in an axial direction 37) from the open position shown in the illustrated embodiment to a closed position. For example, the actuator 14 may include a spring, a hydraulic piston, a manually actuated mechanism (e.g., hand wheel), or other actuation system (e.g., spring-biased actuator, electrical actuator, magnetic actuator, or any combination thereof)
As the gate 22 moves (e.g., axially translates) from the open position to the closed position, the wireline 34 is sheared against the improved seal rings 12. These seal rings 12 include a seat ring supported by a seat holder. The seat ring may be formed from a hard, corrosion resistant material, examples of which have been discussed above.
As shown, each of the improved seal rings 12 is disposed in a respective recess 38 formed in the body 18 of the gate valve 10. More specifically, one improved seal ring 12 is disposed on an upstream side of the gate 22 in the respective recess 38, and another improved seal ring 12 is disposed on a downstream side of the gate 22 in the respective recess 38. The improved seal rings 12 may each include one or more seals (e.g., spring-loaded lip seals) disposed between the respective recess 38 of the body 18 and the improved seal ring 12. Additionally, each improved seal ring 12 may include a seat holder that supports a seat ring. More specifically, the seat ring may be formed from a hard, corrosion resistant material designed for corrosion resistance and/or wear resistance, examples of which have been discussed above. In certain embodiments, the seat ring of each improved seal ring 12 may be replaceable, thereby reducing costs associated with maintaining, repairing, and/or replacing the improved seal rings 12. Additionally, in certain embodiments, existing seal rings may be used to form the seat holder of the improved seal ring 12. In this manner, existing seal rings may be retrofitted to form the improved seal ring 12, thereby recycling and improving existing seal rings.
As mentioned above, the seat ring 52 is supported by the seat holder 50 and retained within the recess 54 of the seat holder 50. For example, in the illustrated embodiment, the seat ring 52 is retained within the recess 54 of the seat holder 50 at least partially by a seal, a lock ring, or a retaining ring 62. More specifically, the seal 62 has a face seal configuration. In other words, the seal 62 is disposed at least partially between an axial surface 64 of the recess 54 and the seat ring 52. The seal 62 is disposed at least partially between a radial surface 66 of the recess 54 and the seat ring 52. As such, the seal 62 is disposed in a corner 68 of the recess 54. In certain embodiments, the seal 62 may be an O-ring, other annular seal, or other face seal. The seal 62 operates to create an interference or friction fit between the seat holder 50 and the seat ring 52. As a result, the seat ring 52 may be retained within the recess 54 of the seat holder 50. In certain embodiments, the seat holder 50 (e.g., the radial surface 66 of the seat holder 50), the seat ring 52 (e.g., circumferential surface of the seat ring 52), and the seal 62 may be assembled to form the improved seal ring 12, and heat may be subsequently applied to the assembled improved seal ring 12 to improve (e.g., cure) the interference fit created between the seat holder 50, the seat ring 52, and the seal 62. In other embodiments, the seat holder 50, the seat ring 52, and the seal 62 may be assembled to form the improved seal ring 12 in a low temperature environment (e.g., using liquid nitrogen). After the improved seal ring 12 is assembled, the improved seal ring 12 may be removed from the low temperature environment, and as the improved seal ring 12 components (e.g., the seat holder 50, the seat ring 52, and the seal 62) increase in temperature, the interference fit created between the seat holder 50, the seat ring 52, and the seal 62 may be improved (e.g., cured).
Furthermore, in certain embodiments, the seat holder 50 may be heated and the seat ring 52 may be cooled before assembly. Heating the seat holder 50 may cause thermal expansion in the seat holder 50 and cooling the seat ring 52 may cause thermal contraction in the seat ring 52. After assembly, the seat holder 50 and the seat ring 52 may return to ambient temperature to create the interference fit to seal and/or hold between the seat holder 50 (e.g., radial surface 66 of seat holder 50) and the seat ring 52 (e.g., circumferential face of seat ring 52). In other words, the seat holder 50 may cool, thereby causing thermal contraction in the seat holder 50, and the seat ring 52 temperature may rise, thereby causing thermal expansion in the seat ring 52. In this manner, the seat holder 50 and the seat ring 52 may engage with one another to form the interference fit.
As mentioned above, the improved seal ring 12 may be formed at least partially from existing seal rings. In this manner, existing seal rings 12 may be recycled and improved to form the improved seal ring 12, thereby reducing costs associated with gate valve 10 maintenance. For example, in certain embodiments, an existing seal ring may be removed from the gate valve 10, and the existing seal ring may be used to form the seat holder 50 of the improved seal ring 12. In other words, an existing seal ring may be machined or modified to form the seat holder 50 having the recess 54 for supporting the seat ring 52. Existing seal rings may be formed from a solid metal or a metal having a coating. As such, existing seal rings may be suitable for forming the seat holder 50 of the improved seal ring 12. For example, the recess 54 may be formed by milling, grinding, turning, or other machining process. That is, an existing seal ring may undergo a machining process to create the recess 54. In this way, the exiting seal ring may be repurposed for use as the seat holder 50 of the improved seal ring 12. After the recess 54 is created, the seat ring 52 may be positioned within the recess 54 and retained by the seal 62, as described above.
In other embodiments, the seat holder 50 may be newly formed. In other words, the seat holder 50 may not be created from an existing seal ring. For example, the seat holder 50 may be cast or otherwise formed form metal to include the recess 54. After the seat holder 50 is formed, the seat ring 52 made of a material, such as a cobalt-based material or other hard, corrosion resistant and/or wear resistant material may be positioned and retained within the recess 54 to form the improved seal ring 12.
The improved seal ring 12 may include other features, such as recesses 70 configured to support seals (e.g., spring loaded lip seals) between the improved seal ring 12 and the recess 38 of the body 18 of the gate valve 10. Additionally, the illustrated embodiment of the improved seal ring 12 also includes a chamfered edge 72 formed in the gate 22 facing surface 58 of the improved seal ring 12. The chamfered edge 72 may improve installation and translation of the improved seal ring 12 between the body 18 and the gate 22 of the gate valve 10.
As similarly described above with respect to the seal 62, the shrink fit material 100 creates an interference fit between the seat holder 50 and the seat ring 52. As will be appreciated, the interference fit may be created by the shrink fit material 100 upon the heating or cooling of the shrink fit material 100 after the seat holder 50, the seat ring 52, and the shrink fit material 100 are assembled to form the improved seal ring 12. For example, after the seat holder 50, the seat ring 52, and the shrink fit material 100 are assembled, heat may be applied to the shrink fit material 100 to cause the shrink fit material 100 to expand between the seat holder 50 and the seat ring 52. Furthermore, during assembly of the improved seat ring 12, the shrink fit material 100 may be cooled to cause thermal contraction of the shrink fit material 100. Thereafter, when the shrink fit material 100 returns to ambient temperature, the shrink fit material 100 may expand to create an interference fit between the seat holder 50 and the seat ring 52, thereby retaining the seat ring 52 within the recess 54 of the seat holder 50.
In certain embodiments, the shrink fit material 100 may be a sleeve or have an annular configuration, such that the shrink fit material 100 fits around a circumference of the seat ring 52. In other embodiments, multiple, non-continuous pieces of shrink fit material 100 may be positioned between the seat ring 52 and the seat holder 50 during assembly of the improved seal ring 12.
As discussed above, in certain embodiments, the seat holder 50 of the improved seat ring 12 may be created by recycling an existing seat ring. That is, an existing seat ring may be machined to formed the recess 54 therein, and the existing seat ring with the recess 54 may serve as the seat holder 50. In this manner, existing seat rings may be recycled and repurposed to form the improved seat ring 12, thereby reducing costs associated with improving and/or maintaining the gate valve 10. Furthermore, in certain embodiments, the seat ring 52 of the improved seal ring 12 may be replaceable. As such, the seat holder 50 may be reused and the seat ring 52 may be replaced as desired, thereby reducing costs associated with maintaining the improved seal ring 12. For example, the seat ring 52 may be removed from the recess 54 and replaced with a newer seat ring 52.
Embodiments of the present disclosure include the improved seal ring 12 for the gate valve 10. More specifically, the improved seal ring 12 includes the seat ring 52 supported by the seat holder 50. For example, as discussed in detail above, the seat ring 52 may be formed from a hard, corrosion resistant and/or wear resistant material, such as Stellite™, other cobalt-based alloy, or other alloy designed for wear resistance. The seat ring 52 may be retained within the seat holder 50 by the seal 62, such as an O-ring, the shrink fit material 100, and/or other retaining material. In certain embodiments, the improved seal ring 12 may be formed from an existing seal ring. For example, an existing seal ring may be machined or modified by form the seat holder 50. Thereafter, the seat holder 50 may be fitted with the seat ring 52, and the seat ring 52 may be retained within the seat holder 50 by a sealing material (e.g., seal 62), a shrink fit material (e.g., shrink fit material 100), or other retaining material. In this manner, existing seal rings may be re-used, refurbished, recycled, or otherwise improved, to form the improved seal ring 12, thereby reducing costs associated with manufacturing and/or maintaining gate valves 10.
While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.
