Steam turbine seal ring finishing apparatus and method of use

Abstract

To provide an apparatus and method for field finishing of a steam turbine seal ring for maintenance or replacement of internal valve components.SOLUTION: The finishing device makes it possible to reduce the outer diameter of the sealing ring. The finishing apparatus includes a first plate including a first circumferentially ramped surface and a second plate including a second circumferentially ramped surface. The second circumferentially inclined surface is spaced a distance from the first circumferentially inclined surface when the finishing apparatus is assembled. The first and second circumferentially inclined surfaces define at least a portion of a wedge-shaped receivingcavity shaped complementary to the shape of the inner diameter of the seal ring to facilitate securing the seal ring in a predetermined position relative to the finishing apparatus while the outer diameter of the seal ring is being finished to a predetermined size.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The field of the invention relates generally to steam turbines, and more particularly to an apparatus and method for on-site finishing of steam turbine seal rings for maintenance or replacement of internal valve components. [Background technology]

[0002] Steam turbines are well-known power generation devices that convert thermal energy into mechanical energy in the generation of electrical power. During operation, high-pressure, high-temperature steam is input from an inlet to the steam turbine through a main shutdown valve and a control valve. Components of the main shutdown valve and the control valve, including but not limited to seal rings located in the valve casing, may require maintenance and / or replacement during planned shutdowns of the steam turbine. The seal rings require an outer diameter for installation that closely matches the inner diameter of the valve casing. Currently, seal rings are provided with an oversized outer diameter (i.e., a diameter larger than the inner diameter of the valve casing), which is reduced or finished in the field to allow the seal ring to substantially match, i.e., shrink to, the actual inner diameter of the valve casing on which it will be installed in the steam turbine.

[0003] Known finishing apparatus and methods used to reduce the desired outer diameter of a seal ring in a customized manner to ensure a proper fit, and therefore a proper seal, at the installation point within a valve casing of a steam turbine are disadvantageous in several aspects, and improvements are desirable. For example, due to the overall size of at least some seal rings, it can be difficult to secure the seal ring in a position that allows the outer diameter ring to be machined. Additionally, due to the beveled surfaces of the seal ring, the seal ring is machined using known finishing machines. Therefore, there is a need for a system and method for finishing steam turbine seal rings in-situ in a cost-effective and less labor-intensive manner compared to known finishing machines. Summary of the Invention

[0004] In one aspect, a finishing device for use in reducing the outer diameter of a seal ring is provided. The finishing device includes a first plate including a first circumferentially inclined surface and a second plate including a second circumferentially inclined surface. The second circumferentially inclined surface is spaced a distance from the first circumferentially inclined surface when the finishing device is assembled. The first and second circumferentially inclined surfaces define at least a portion of a wedge-shaped receiving cavity that is complementary in shape to the inner diameter of the seal ring, facilitating securing the seal ring in a predetermined position relative to the finishing device while the outer diameter of the seal ring is being finished to a predetermined size.

[0005] In another aspect, a method for finishing a seal ring for field installation in a valve casing is provided. The method includes determining a finished outer diameter of the seal ring to facilitate a seal between the valve casing and the finished seal ring within a predetermined tolerance, and coupling the seal ring into a finishing device including first and second plates positioned so that at least a portion of the seal ring is received between the first and second plates. The method also includes clamping the seal ring between the first and second plates so that a portion of the seal ring is received in a cavity having a shape complementary to a shape defined between the first and second plates and a portion of the seal ring extends radially outward from a circumferential outer edge of each of the first and second plates, and reducing the outer diameter of the seal ring to the finished diameter.

[0006] In yet another aspect, a finishing apparatus for use in finishing a seal ring is provided. The finishing apparatus includes a substantially flat first plate defined by an outer edge including a first inclined surface and a substantially flat second plate defined by an outer edge including a second circumferential inclined surface that substantially mirrors the first inclined surface, such that a triangular cavity is defined between the first and second circumferential inclined surfaces when the finishing apparatus is assembled. The triangular cavity is oriented to substantially center the seal ring relative to the finishing apparatus, such that a portion of the seal ring is retained between the first and second circumferential inclined surfaces when the finishing apparatus is assembled, while a portion of the seal ring extends radially outward from the first and second circumferential inclined surfaces. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic diagram of an exemplary turbomachine in which a seal ring may be installed; [Figure 2] 2 is a cross-sectional view of an exemplary valve assembly including an exemplary seal ring that may be used with the turbomachine shown in FIG. 1. [Figure 3] 3 is an exploded view of an exemplary seal ring finishing device for use in reducing the outer diameter of a seal ring for optimal installation in the valve assembly shown in FIG. 2. [Figure 4] FIG. 4 is a top perspective view of the finishing device shown in FIG. 3 with a portion of the seal ring clamped. [Figure 5] 5 is a cross-sectional view of the finishing device shown in FIG. 4 with the sealing ring clamped. [Figure 6] FIG. 6 is a top view of a first portion of the finishing device shown in FIGS. 3 to 5. [Figure 7] 7 is a side view of a first portion of the finishing device shown in FIG. 6. [Figure 8] FIG. 6 is a top view of a second portion of the finishing device shown in FIGS. 3 to 5. [Figure 9] 9 is a cross-sectional view of a second portion of the finishing device shown in FIG. 8. DETAILED DESCRIPTION OF THE INVENTION

[0008] Known oversized replacement seal rings present particular challenges in the installation of the seal ring on a valve casing within a turbomachine, such as a steam turbine on the high-pressure side of the turbomachine. Specifically, the overall size and shape of the oversized seal ring complicates any attempt to reduce the outer diameter of the seal ring to match the inner diameter of the valve casing in the field of the turbomachine during a planned turbine shutdown or outage. Existing finishing equipment and processes for reducing the outer diameter of the seal ring have difficulty meeting the tolerances required for installation, and as a result, several trial and error attempts can be encountered in properly completing the installation of the seal ring. Such trial and error can result in time delays in completing the installation of the seal ring and / or undesirable discard of seal rings that do not meet the required tolerances due to the difficulties encountered in reducing the outer diameter of the seal ring. Accordingly, finishing equipment and methods that address and overcome such problems are described herein. Aspects of the method are partially explicitly described and partially implicitly disclosed in the following description.

[0009] 1 schematically illustrates a portion of an exemplary turbomachine 100 in which an exemplary seal ring (shown in FIG. 2 ) may be installed, which must be finished on-site prior to installation. In the exemplary embodiment, turbomachine 100 includes a high-pressure section 102 that receives steam from one or more inlets and one or more valve blocks 104 that enable the steam to be output to, for example, a turbine 106 that is used to convert thermal energy of the steam into rotational energy, which is then routed to a generator 108. In the exemplary embodiment, valve block 104 includes multiple valves that can combine the outputs before providing the steam to turbine 106. For example, the valves in valve block 104 can operate as main shutoff valves or control valves during operation of turbomachine 100.

[0010] In the depicted example, turbomachine 100 also includes an intermediate-pressure section 110 including one or more valve blocks 112 that receive steam from turbine 106 and direct the steam to an outlet. Optionally, the turbomachine may include a low-pressure section (not shown) including one or more valve blocks before the steam exits turbomachine 100. Intermediate-pressure valve block 112 and / or the low-pressure valve block may similarly include multiple valves that operate as stop valves or control valves. Output from the valves in intermediate-pressure valve block 112 and / or the output from the low-pressure valve block may be combined before the steam exits the turbomachine.

[0011] Because the fabrication, assembly, and operation of turbomachine 100 are well known and understood by those skilled in the art, further description thereof will be omitted for the sake of brevity, except for the fabrication and exemplary embodiments of the finishing apparatus and seal ring. While the seal rings described below are perhaps most beneficially used with valves included in high-pressure valve block 104 in high-pressure section 102 of turbomachine 100, the seal rings may likewise be used with any other valves that include seal rings, including, but not limited to, valves used in intermediate-pressure valve block 112 in intermediate-pressure section 110 and / or valves associated with low-pressure sections of turbomachine 100, if provided. However, it is recognized that the benefits of the apparatus and methods described below for facilitating installation of seal rings are not necessarily limited to the turbomachines described herein. Accordingly, the apparatus and methodologies described below may be beneficially applied to other seal ring applications presenting similar problems and / or any other applications in which the benefits of the finishing apparatus and methods are realized.

[0012] FIG. 2 is a cross-sectional view of an exemplary portion of a valve assembly 150 including a valve casing 152 having a round, circular inner diameter (ID) and a round outer diameter (OD). The valve casing 152 may be provided, for example, in the valve block 104 of the turbomachine 100 ( FIG. 1 ) or any of the other valve blocks described herein. The ID defines a longitudinal, generally cylindrical opening, space, or bore through which various steam valve components may reside and extend. In the exemplary embodiment, such steam valve components include at least one seal ring 154 having a round, circular outer diameter OD that is finished within predetermined tolerances to sealingly fit the actual ID of the valve casing 152. The seal ring 154 extends circumferentially adjacent the ID of the valve casing 152 for a full 360° circumference of the ID.

[0013] In a contemplated example, the outer diameter OD of the sealing ring 154 may initially be oversized by approximately 4 mm relative to the expected ID of the associated valve casing for installation of the sealing ring 154. Thus, in an exemplary embodiment, the outer diameter OD of the sealing ring 154 may be finished to reduce the outer diameter OD to fall within a range of valve casing IDs that can be individually determined, verified, or verified at the time of sealing ring replacement and in the field for the actual valve. In some embodiments, sets of sealing rings 154 with different oversized initial diameters and similar or different degrees of oversizing may be provided to facilitate flexible fitting after finishing for use with different valves.

[0014] In the exemplary embodiment, the seal ring 154 includes a wedge-shaped or triangular cross-sectional portion 158 defined by a beveled edge surface 155 that extends obliquely relative to the ID of the valve casing 152. Additionally, the seal ring 154 includes inwardly-dependent edge surfaces 155 extending from the outer diameter OD that in combination define a pointed leading edge 156 extending along the seal ring's inner diameter. Thus, the inner diameter ID of the seal ring 154 is non-uniform along the longitudinal axis of the valve casing 152. As shown in FIG. 2 , the non-uniform inner diameter ID is defined along the triangular or wedge-shaped cross-sectional portion 158 of the seal ring 154, where the outer diameter OD coincides with the inner diameter ID of the valve casing 152. Specifically, the inner diameter ID of the seal ring 154 is smallest along the pointed leading edge 156 and extends above and below the pointed edge 156 in a substantially linear manner toward the outer diameter OD of the seal ring 154.

[0015] Unlike other types of seal rings that include generally parallel, opposing flat surfaces between the inner and outer diameters (which lend themselves to accurate machining using relatively simple machining fixtures), the uneven inner diameter ID resulting from the wedge-shaped cross-sectional portion 158 of the seal ring 154 does not include flat, parallel surfaces, which makes it difficult to securely clamp the seal ring 154, i.e., from above and below using clamps in known finishing equipment and / or using known finishing methods that attempt to reduce its original oversized outer diameter OD to a smaller diameter that is approximately the same size as the inner diameter ID of the valve casing 152. As a result, the inability to securely clamp the seal ring 154 for finishing can increase the likelihood of error in the desired results and, more specifically, can result in a machined seal ring that has a modified diameter relative to its original oversized diameter but does not meet the tolerances required for the valve or associated turbomachinery. Thus, trial and error in finishing the seal ring 154 can result.

[0016] Trial and error due to the challenge of securely retaining the seal ring 154 while its oversized initial outer diameter OD is reduced tends to increase installation costs of the seal ring 154 and may result in longer planned turbine downtime than originally anticipated. Additionally, some seal rings 154 may necessarily need to be discarded when some or all of their outer diameters are inadvertently reduced too much to provide the necessary seal. In such cases, the seal ring may need to be discarded and another seal ring refinished to complete installation in the valve casing. Similarly, if the oversized outer diameter OD is not sufficiently reduced, additional finishing of the seal ring is required. Such an event may require an extension of the planned turbine downtime to complete proper installation of the seal ring 154. Of course, such effects can accumulate depending on the number of valves in the valve block 104 and / or 112 ( FIG. 1 ) that require replacement seal rings. Given that the outer diameters OD of different valve casings may differ slightly from one another, the trial and error process of successfully reducing the outer diameter of a seal ring for installation in different valve casings can become even more complicated.

[0017] 3 is an exploded view of an exemplary seal ring finishing apparatus 200 that overcomes the aforementioned difficulties and efficiently facilitates accurate and reliable reduction of an oversized initial outer diameter OD of a seal ring 154 for its proper installation into a particular valve assembly 150 (shown in FIG. 2 ). Thus, using the finishing apparatus 200 and associated methodology, a seal ring can be easily installed into a valve assembly 150 and turbomachine 100 in less time and at lower cost, while beneficially reducing, if not eliminating, the amount of wasted material or the potential for extending the length of a planned turbine outage required to complete a valve component replacement.

[0018] As shown in Figures 3-9, in the exemplary embodiment, finishing device 200 includes an upper portion 202 and a lower portion 206. Upper portion 202, in the exemplary embodiment, is in the form of a round, substantially circular plate 203 having a round, substantially circular central opening 204 defined therein extending therethrough. Lower portion 206, in the exemplary embodiment, includes a round, substantially circular plate 208 and a substantially cylindrical shaft or stem 210 extending through the round, substantially circular central opening defined in plate 208. Stem 210 is positioned a relatively short distance d above an upper surface 209 of plate 208 as shown. a and extends a relatively long distance d below the bottom surface 211 of the plate 208. b The longitudinal axis L of the stem 210 s extend substantially perpendicular to top and bottom surfaces 209 and 211, respectively, of plate 208. Further, in an exemplary embodiment, stem 210 and plate 208 may be securely coupled to one another, such as via a welding process, to provide a one-piece assembly for use in finishing seal ring 154.

[0019] Plate 203, in the exemplary embodiment, may be provided separately and received over protruding upper end 213 of stem 210 and securely fastened to plate 208 over seal ring 154. Fasteners 212, such as bolts or screws, are insertable through fastener openings 215 and 217 defined in each respective plate 203 and 208, enabling seal ring 154 to be securely fastened to finishing apparatus 200. In the exemplary embodiment, four fasteners 212 and four fastener holes 215 and 217 are shown, with the fasteners and holes uniformly spaced apart at approximately 90° radial positions from one another to provide a substantially uniform clamping force around the circumference of seal ring 154. In alternative embodiments, any other fastening mechanism that enables finishing apparatus 200 to function as described herein may be used. Additionally, in alternative embodiments, more or less than four fasteners 212 may be used, so long as sufficient clamping force is provided to enable the seal ring 154 to be securely held in place to facilitate efficient, accurate, and repeatable finishing of the outer diameter OD of the seal ring 154.

[0020] After the seal ring 154 is secured in place between the plates 203 and 208, the oversized initial outer diameter OD of the seal ring 154 protrudes circumferentially from the outer peripheral edges of the plates 203 and 208. Therefore, the protruding outer diameter OD of the seal ring 154 can be machined with a tool such as a lathe to reduce the outer diameter OD and conform to the particular valve casing in which the seal ring 154 is installed. In one embodiment, the stem 210 may be coupled to and rotatable by the lathe to facilitate machining. In another embodiment, any other suitable machining tool can be rotated around the outer diameter OD of the seal ring 154 to reduce the outer diameter OD to match the inner diameter ID of the particular valve casing in which the seal ring 154 is installed.

[0021] 4 is a top perspective view of finishing apparatus 200 in assembled form, showing a portion of seal ring 154 clamped therein. The angled surfaces defining pointed inner edge 156 (FIGS. 2 and 5) of seal ring 154 are securely clamped between plates 203 and 208, and the outer diameter OD of seal ring 154 initially projects circumferentially outward beyond the circumferential edges of each plate 203 and 208, allowing for machining to reduce the outer diameter OD.

[0022] 5 is a cross-sectional view of finishing apparatus 200 illustrating that upper and lower plates 203 and 208 each include an inclined peripheral surface 205 that presses against one of inner beveled edge surfaces 155 of seal ring 154. Inclined edge surfaces 205 of plates 203 and 208 face each other (e.g., one has a positive slope and the other has a negative slope), thereby defining a wedge-shaped receiving area 301 between spaced apart plates 203 and 208. In the exemplary embodiment, the formed wedge-shaped receiving area 301 substantially complements wedge portion 158 defined in seal ring 154, facilitating stable positioning of seal ring 154 within apparatus 200 and facilitating the generation of a substantially uniform compressive force circumferentially on seal ring 154 when held within finishing apparatus 200.

[0023] Additionally, when received in apparatus 200 as shown, sealing ring 154 is substantially centered within apparatus 200 and may be securely held therein via fasteners 212 that apply a substantially uniform compressive force to wedge-shaped portion 158 of sealing ring 154. Pointed edge 156 of inner sealing ring 154 extends between beveled edge surfaces 205 of plates 203 and 208, while wedge-shaped portion 158 of sealing ring 154 is clamped with sufficient compressive force.

[0024] FIG. 6 is a top view of the lower portion 206 of the finishing apparatus 200 shown in FIGS. 3-5, and FIG. 7 is a side view of the lower portion 206 of the illustrated finishing apparatus 200. The plates 208 in the lower portion 206 include peripheral edges 214 that include beveled edges 216 defined by beveled surfaces 205. Except along these surfaces 205, the plates 208 are otherwise substantially flat and have a substantially uniform thickness T p The angled surface 205 receives the underside of the wedge-shaped portion 158 of the seal ring 154 when the seal ring 154 is placed on the plate 208. Because the angled edge 216 aligns with the lower angle of the wedge-shaped portion 158, in the exemplary embodiment, the seal ring 154 is easily and intuitively guided into a substantially centered position relative to the plate 208.

[0025] 8 is a top view of the upper portion 202 of the finishing apparatus 200, and FIG. 9 is a cross-sectional view of the upper portion 202 of the apparatus 200. The plate 203 includes a periphery 220 defined by an inclined or beveled surface 205. Except along these surfaces 205, the plate 203 is otherwise substantially flat and has a substantially uniform thickness T p 2. The angled surface 205 receives the upper side of the wedge-shaped cross-sectional portion 158 of the seal ring 154 when the plate 203 is placed over the seal ring 154. Because the angled surface 205 is substantially aligned with the wedge-shaped cross-sectional portion 158 of the seal ring, the plate 203 is easily and intuitively guided into a centered position relative to the seal ring 154. Insertion of the plate 203 over the stem 210 further centers the plate 203 and seal ring 154 relative to the plate 208 prior to insertion of the fasteners 212 when the fastener holes in the plates 203 and 208 are aligned.

[0026] The substantially uniform outer diameters of plates 203 and 208 further provide a visual guide for verifying that seal ring 154 is substantially centered when it is clamped to apparatus 200 via insertion and tightening of fasteners 212. Once securely clamped, the oversized initial outer diameter OD of seal ring 154 can be efficiently and reliably reduced to a determined desired size that matches the determined size of valve casing inner diameter ID. Once finished to the correct size, fasteners 212 are removed, thus removing plate 203 and allowing access to the finished seal ring 154 for assembly with valve casing 152.

[0027] As desired or required, different sets of finishing devices 200 can be provided to accommodate different oversized diameters of the seal rings, using other similar structures and methodologies for finishing and installing the seal rings.

[0028] It is believed that the benefits and advantages of the finishing apparatus and method of the present invention have now been fully described in connection with the disclosed exemplary embodiments.

[0029] Described herein are exemplary systems and methods for finishing seal rings in the field in a cost-effective and reliable manner. Accordingly, a finishing apparatus and method of use are described herein that address and overcome problems associated with known finishing apparatus and known methods for finishing seal rings. Furthermore, the described systems and methods use an assembly that applies a substantially constant compressive force to an oversized seal ring that requires finishing in the field of the valve casing in which the seal ring is installed. The assembly secures the seal ring to ensure that the seal ring is substantially centered and secured. The exemplary systems and methods described herein offer several advantages over conventional designs and processes, including, for example, reducing the time delay in reducing the diameter of an oversized seal ring and reducing the costs and time delays associated with installing the seal ring.

[0030] The above description is intended to be illustrative only, and those skilled in the art will recognize that changes can be made to the described embodiments without departing from the scope of the invention disclosed. Modifications that fall within the scope of the invention will be apparent to those skilled in the art in light of a review of the present disclosure, and such modifications are intended to fall within the scope of the appended claims. The systems described herein are not limited to the specific embodiments described herein; rather, portions of the various systems may be utilized independently and separately from other systems described herein.

[0031] Although specific features of various embodiments of the invention may be shown in some drawings and not in others, this is for convenience only. Moreover, references to "one embodiment" in the above description are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. In accordance with the principles of the invention, any feature of a drawing may be referenced and / or claimed in combination with any feature of any other drawing.

[0032] Further aspects of the invention are provided by the subject matter of the following clauses.

[0033] 1. A finishing device for use in reducing an outer diameter of a seal ring, comprising: a first plate including a first circumferentially inclined surface; and a second plate including a second circumferentially inclined surface spaced a distance from the first circumferentially inclined surface when the finishing device is assembled, the first and second circumferentially inclined surfaces defining at least a portion of a wedge-shaped receiving cavity that is complementary in shape to the inner diameter of the seal ring, facilitating securing the seal ring in a predetermined position relative to the finishing device while the outer diameter of the seal ring is being finished to a predetermined size.

[0034] The finishing device of the preceding clause, wherein the device further includes a stem extending from an upper surface of the first plate, the stem cooperating with the first and second circumferential inclined surfaces to facilitate self-centering of the seal ring relative to the finishing device.

[0035] 10. The finishing device of any one of the preceding clauses, wherein the second plate further includes a central opening sized to receive a portion of the stem therethrough.

[0036] The finishing device of any one of the preceding clauses, further comprising a plurality of fastening mechanisms extending through a plurality of holes defined in the first and second plates, the fasteners facilitating securing the seal ring within the finishing device.

[0037] 10. The finishing apparatus of claim 1, wherein the plurality of fastening mechanisms are circumferentially spaced to allow a substantially constant compressive force to be exerted on the seal ring.

[0038] The finishing apparatus of any one of the preceding clauses, wherein a finishing tool enables a lathe to reduce the outer diameter of the seal ring.

[0039] 2. The finishing device of claim 1, wherein the stem is rotatable relative to the tool.

[0040] 1. A method for finishing a seal ring for field installation in a valve casing, the method comprising: determining a finished outer diameter of the seal ring to facilitate a seal between the valve casing and the finished seal ring within a predetermined tolerance; coupling the seal ring into a finishing apparatus including first and second plates positioned such that at least a portion of the seal ring is received between the first and second plates; clamping the seal ring between the first and second plates such that a portion of the seal ring is received in a cavity having a shape complementary to a shape defined between the first and second plates and a portion of the seal ring extends radially outward from a circumferential outer edge of each of the first and second plates; and reducing the outer diameter of the seal ring to the finished diameter.

[0041] 10. The method of claim 9, wherein clamping the seal ring further comprises: seating a wedge-shaped portion of an inner diameter of the seal ring within a triangular cavity defined by the first and second plates; and securing the first plate to the second plate such that a stem extending substantially perpendicularly from the second plate extends a distance through an opening defined in the first plate.

[0042] 10. The method of any one of the preceding clauses, further comprising inserting fasteners through holes defined in the first and second plates to create a compressive force above and below the wedge-shaped portion of the sealing ring.

[0043] 10. The method of claim 1, wherein reducing the oversized outer diameter to the finished diameter includes facilitating reducing the outer diameter of the sealing ring to the finished diameter using a finishing tool while the sealing ring is held within the finishing apparatus.

[0044] The method of any one of the preceding clauses, wherein using a finishing tool further comprises using a lathe to facilitate reducing the outer diameter of the seal ring.

[0045] The method of any one of the preceding clauses, further comprising rotating the stem relative to the finishing tool.

[0046] 10. The method of any one of the preceding clauses, further comprising rotating the finishing tool relative to the finishing device.

[0047] 10. The method of any one of the preceding clauses, further comprising installing the finished seal ring in the valve casing.

[0048] 1. A finishing apparatus for use in finishing a seal ring, comprising: a substantially flat first plate defined by an outer edge including a first inclined surface; and a substantially flat second plate defined by an outer edge including a second circumferential inclined surface that substantially mirrors the first inclined surface, whereby a triangular cavity is defined between the first and second circumferential inclined surfaces when the finishing apparatus is assembled, the triangular cavity being oriented to substantially center the seal ring relative to the finishing apparatus, whereby a portion of the seal ring is captured between the first and second circumferential inclined surfaces while a portion of the seal ring extends radially outward from the first and second circumferential inclined surfaces when the finishing apparatus is assembled.

[0049] The finishing device of the preceding clause, wherein the portion of the seal ring held between the first and second circumferential inclined surfaces is shaped complementarily to the shape of the triangular cavity defined between the first and second circumferential inclined surfaces.

[0050] 10. The finishing device of claim 1, further comprising a plurality of fastening mechanisms sized to extend through a plurality of holes defined in the first and second plates, the fasteners facilitating securing the seal ring within the finishing device such that a substantially constant compressive force is exerted on the seal ring.

[0051] This specification uses examples to disclose the invention, including the best mode, and to enable any person skilled in the art to practice the invention, including making and using any device or system and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ substantially from the literal language of the claims. [Explanation of symbols]

[0052] 100 Turbomachinery 102 High-pressure section 104 Valve Block 106 Turbine 108 Generator 110 Medium pressure section 112 Medium pressure valve block 150 Valve Assembly 152 Valve casing 154 Seal ring 155 Medial beveled edge surface 156 Sharp leading edge / sharp edge / sharp inner edge 158 Wedge-shaped or triangular cross-section / wedge-shaped section 200 Finishing Equipment 202 Upper part 203 Plate 204 Central opening 205 Inclined Peripheral Surface / Sloped Surface 206 Lower part 208 Plate 209 Top surface 210 stem 211 bottom 212 Fasteners 213 protruding top 214 Periphery 215 Fastener opening / fastener hole 216 Sloped Edge 217 Fastener opening / fastener hole 220 Periphery 301 Wedge-shaped receptive area / Wedge-shaped receptive cavity d a Relatively short distance d b Relatively long distance L s Longitudinal Axis T p Thickness ID Inner Diameter OD outer diameter

Claims

1. 1. A finishing device (200) for use in reducing the outer diameter (OD) of a seal ring (154), comprising: a first plate (203) including a first circumferential inclined surface (205); a second plate (208) including a second circumferential inclined surface (205) spaced a distance from the first circumferential inclined surface (205) when the finishing device (200) is assembled, the first and second circumferential inclined surfaces (205) defining at least a portion of a wedge-shaped receiving cavity (301) that is complementary in shape to an inner diameter (ID) of the sealing ring (154), facilitating securing the sealing ring (154) in a predetermined position relative to the finishing device (200) while the outer diameter (OD) of the sealing ring (154) is being finished to a predetermined size; A finishing device (200) comprising:

2. 2. The finishing device (200) of claim 1, further comprising a stem (210) extending from an upper surface of the first plate (203), the stem (210) cooperating with the first and second circumferential inclined surfaces (205) to facilitate self-centering of the seal ring (154) relative to the finishing device (200).

3. The finishing device (200) of claim 2, wherein the second plate (208) further comprises a central opening (204) sized to receive a portion of the stem (210) therethrough.

4. 4. The finishing apparatus (200) of claim 3, further comprising a plurality of fastening mechanisms extending through a plurality of holes (215, 217) defined in the first and second plates (203, 208), the fasteners (212) facilitating securing the seal ring (154) within the finishing apparatus (200).

5. The finishing device (200) of claim 4, wherein the plurality of fastening mechanisms are circumferentially spaced to enable a substantially constant compressive force to be exerted on the seal ring (154).

6. The finishing apparatus (200) of claim 5, wherein a finishing tool enables a lathe to reduce an outside diameter (OD) of the seal ring (154).

7. The finishing device (200) of claim 5, wherein the stem (210) is rotatable relative to the tool.

8. A method for finishing a seal ring (154) for field installation in a valve casing (152), comprising: determining a finished outside diameter (OD) of the seal ring (154) to facilitate a seal between the valve casing (152) and the finished seal ring (154) within a predetermined tolerance; coupling the seal ring (154) into a finishing device (200) including first and second plates (203, 208) positioned such that at least a portion of the seal ring (154) is received between the first and second plates (203, 208); clamping the seal ring (154) between the first and second plates (203, 208) such that a portion of the seal ring (154) is received within a cavity having a shape complementary to a shape defined between the first and second plates (203, 208) and such that a portion of the seal ring (154) extends radially outward from a circumferential outer edge of each of the first and second plates (203, 208); reducing the outer diameter (OD) of said seal ring (154) to said finished diameter; A method comprising:

9. Clamping the seal ring (154) seating a wedge-shaped portion (158) of an inner diameter (ID) of said seal ring (154) within a triangular cavity defined by said first and second plates (203, 208); securing the first plate (203) to the second plate (208) such that a stem (210) extending substantially perpendicularly from the second plate (208) extends a distance through an opening (204) defined in the first plate (203); The method of claim 8 further comprising:

10. 10. The method of claim 9, further comprising inserting fasteners (212) through holes (215, 217) defined in the first and second plates (203, 208) to create a compressive force above and below the wedge-shaped portion (158) of the seal ring (154).

11. 9. The method of claim 8, wherein reducing the oversized outside diameter (OD) to the finished diameter comprises using a finishing tool to facilitate reducing the outside diameter (OD) of the seal ring (154) to the finished diameter while the seal ring (154) is held within the finishing apparatus (200).

12. The method of claim 11, wherein using a finishing tool further comprises using a lathe to facilitate reducing the outer diameter (OD) of the seal ring (154).

13. The method of claim 11, further comprising rotating the stem (210) relative to the finishing tool.

14. The method of claim 11, further comprising rotating the finishing tool relative to the finishing device (200).

15. The method of claim 14, further comprising installing the finished seal ring (154) in the valve casing (152).

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