Rotary valve trim assembly including metal sealing element

Abstract

The invention relates to a trim assembly for a rotary valve and a rotary valve including such a trim assembly. The trim assembly includes a valve stem, a flow control element, a sealing element, and a retainer. A flow control element is coupled to the valve stem and adapted to be disposed in a valve body of the rotary valve. The flow control element is movable between an open position and a closed position. The sealing element is adapted to be disposed in the valve body such that the sealing element is disposed proximate to the flow control element to sealingly engage the flow control element when the flow control element is in the closed position. The retainer is adapted to be coupled to the valve body and configured to retain the seal ring in position proximate the flow control element. The sealing element is made of a metal material and has a mouth facing the retainer.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to rotary valves, and more particularly to a rotary valve trim assembly including a metallic seal element. BACKGROUND

[0002] Process control systems often employ rotary valves, such as ball valves, butterfly valves, eccentric disc valves, eccentric plug valves, etc., to control the flow of process fluids. Rotary valves generally include a valve trim assembly having a seat disposed in a fluid path about a flow bore and a fluid control element (e.g., a disc, a ball, etc.) disposed in the fluid path and rotatably coupled to the body of the valve by a stem or shaft. To control the flow of fluid through some rotary valves, the position of the fluid control element can be varied from a closed position, in which the fluid control element is in sealing engagement with the seat to prevent fluid flow through the flow bore, to a fully open or maximum flow position, in which the fluid control element is spaced apart from the seat to allow fluid flow through the flow bore. SUMMARY

[0003] According to a first exemplary aspect, there is provided a trim assembly for use in a rotary valve, the rotary valve comprising a valve body. The trim assembly comprises a valve stem, a flow control element, a seal element, and a retainer. The flow control element is coupled to the valve stem and is adapted to be disposed in the valve body and movable between an open position and a closed position. The seal element is adapted to be disposed in the valve body such that the seal element is disposed proximate the flow control element, wherein the seal element sealingly engages the flow control element when the flow control element is in the closed position. The retainer is adapted to be coupled to the valve body and configured to retain the seal element in position proximate the flow control element. The seal element is made of a metallic material and has a mouth portion facing the retainer.

[0004] According to a second exemplary aspect, there is provided a trim assembly for use in a rotary valve, the rotary valve comprising a valve body. The trim assembly comprises a valve stem, a flow control element, a seal element, and a retainer. The flow control element is coupled to the valve stem and is adapted to be disposed in the valve body and movable between an open position and a closed position. The seal element is adapted to be disposed in the valve body such that the seal element is disposed proximate the flow control element, wherein the seal element sealingly engages the flow control element when the flow control element is in the closed position. The retainer is adapted to be coupled to the valve body and configured to retain the seal element in position proximate the flow control element. The seal element is a C-shaped seal ring made of a metallic material.

[0005] According to a third exemplary aspect, there is provided a rotary valve. The rotary valve includes a valve body, a valve stem, a flow control element, a sealing element, and a retainer. The valve body defines a valve inlet, a valve outlet, and a valve interior in fluid communication with the valve inlet and the valve outlet. The valve stem is movably disposed in a central bore of the valve body. The flow control element is movably disposed in the valve interior by the valve stem to control fluid flow between the valve inlet and the valve outlet. The flow control element is movable between an open position, in which fluid flow between the valve inlet and the valve outlet is permitted, and a closed position, in which fluid flow between the valve inlet and the valve outlet is prevented. The sealing element is disposed in a recess of the valve body such that the sealing element is disposed immediately adjacent to the flow control element, wherein the sealing element sealingly engages the flow control element when the flow control element is in the closed position. The retainer is coupled to the valve body and is configured to retain the sealing element in the recess of the valve body. The sealing element is a C-shaped seal ring made of a metallic material.

[0006] According to any one or more of the above first, second, or third exemplary aspects, the inner assembly or the rotary valve can include any one or more of the following further preferred forms.

[0007] In a preferred form, the sealing element is a C-shaped seal ring.

[0008] In another preferred form, the sealing element is disposed between a peripheral edge of the flow control element and an inner surface of the retainer.

[0009] In another preferred form, the sealing element is entirely made of a metallic material.

[0010] In another preferred form, the biasing element is at least partially disposed inside the sealing element.

[0011] In another preferred form, the C-shaped seal ring has a mouth portion facing the retainer.

[0012] In another preferred form, a coating is applied on an outer surface of the sealing element.

[0013] In another preferred form, a sleeve is disposed in the valve body and is sized to receive and surround a portion of the valve stem.

[0014] In another preferred form, the retainer is coupled to an outer surface of the valve body.

[0015] In another preferred form, a second sealing element is disposed between the retainer and the valve body.

[0016] In another preferred form, the retainer has an inner surface, and wherein the inner surface is disposed radially outward of the C-shaped seal ring. BRIEF DESCRIPTION OF DRAWINGS

[0017] The disclosure is believed to be novel and the novel features are set forth with particularity in the appended claims. The disclosure, both as to organization and manner of operation, together with the associated drawings are best understood by reference to the following description. Like reference numerals are used to refer to like elements throughout the several views of the drawings, in which:

[0018] Figure 1 is a cross-sectional view of another example of a rotary control valve constructed in accordance with the teachings of the present disclosure;

[0019] Figure 2 is a close-up view of a portion of the rotary control valve in Figure 1 ; and

[0020] Figure 3 is a cross-sectional view of another example of a rotary control valve constructed in accordance with the teachings of the present disclosure; Figure 1 and Figure 2 is a close-up view of a portion of the rotary control valve in DETAILED DESCRIPTION

[0021] The present disclosure relates to a rotary valve trim assembly for use in a rotary valve that addresses the problems of known rotary valve trim assemblies. The rotary valve trim assembly disclosed herein generally includes a valve stem (or shaft), a flow control element coupled to the valve stem, and a metallic sealing element. When the valve trim assembly is disposed in a valve body of a rotary valve, the valve stem drives the flow control element to move between a closed position and a fully open position. The metallic sealing element is configured to sealingly engage the flow control element when the flow control element is in the closed position, thereby achieving a tight shut-off. Beneficially, however, the inventors have discovered that the metallic sealing element provides such a tight shut-off at very high temperatures and has a long service life. For example, when the sealing element is made of SS 316L, the metallic sealing element provides such a tight shut-off at temperatures up to 316 degrees Celsius (about 600 degrees Fahrenheit). However, when the sealing element is made of Alloy 6, the metallic sealing element provides such a tight shut-off at temperatures up to 649 degrees Celsius (about 1200 degrees Fahrenheit). As another example, the inventors have discovered that the metallic sealing element has a service life of more than 4000 operating cycles at ambient temperatures. At the same time, the metallic sealing element is easier and more cost effective to manufacture and install, and the metallic sealing element can be manufactured in different sizes to obtain the advantages of different sizes of the rotary valve discussed herein.

[0022] Figure 1 and 2One example of a rotary valve 100 constructed in accordance with the principles of the present disclosure is shown. The rotary valve 100 generally includes a valve body 104 and a valve trim assembly 108 coupled to the valve body 104. The valve body 104 is generally cylindrical and has a first end 120 defining a fluid inlet 124 of the rotary valve 100, a second end 128 disposed opposite the first end 120 and defining a fluid outlet 132, and a fluid passage 136 extending along a flow axis 140 between the fluid inlet 124 and the fluid outlet 132. The valve body 104 also includes a first central bore 144 and a second central bore 148, both extending along a longitudinal center axis that is substantially or completely perpendicular to the flow axis 140. The first central bore 144 is formed in a first portion or top of the valve body 104, while the second central bore 148 is formed in a second portion or bottom of the valve body 104, such that the first central bore 144 and the second central bore 148 are disposed on opposite sides of the fluid passage 136.

[0023] At the same time, the valve trim assembly 108 generally includes a valve stem 152 and a flow control element 156. The valve stem 152 (which can also be referred to as a valve shaft) is at least partially disposed in the valve body 104 along a longitudinal center axis 162. More specifically, the valve stem 152 is disposed in and extends through the first central bore 144, the second central bore 148, and a central portion of the fluid passage 136. In this example, the valve stem 152 has a first end 168 or top end of the valve stem 152 disposed outside of the valve body, and a second end 172 or bottom end of the valve stem 152 disposed in the second central bore 148 opposite the first end 168. However, in other examples, the first end 168 of the valve stem 152 can also be disposed in the first central bore 144. The flow control element 156 is coupled to the valve stem 152 and disposed in the fluid passage 136 to control fluid flow through the fluid passage 136. In this example, the flow control element 156 takes the form of a valve disc that is coupled to the valve stem 152 by inserting a plurality of pins 176 into a plurality of holes 180 formed in a portion of the valve stem 152 between the first end 168 and the second end 172, respectively. However, in other examples, the flow control element 156 can instead take the form of a ball element or other type of flow control element. In other examples, the flow control element 156 can also be coupled to the valve stem 152 in different ways (e.g., by one or more pins 176, by one or more different fasteners, or otherwise) and / or in different locations.

[0024] The trim assembly 108 also generally includes a seal element 200 and a retainer 204 for the seal element 200. The seal element 200 is a seal ring made or formed from a metallic material such as steel (e.g., SS 316), aluminum, or an alloy (e.g., Alloy 600, Alloy 718, Aluminum Alloy 1100), etc. The seal element 200 preferably takes the form of a C-shaped annular seal ring having a mouth portion 208 and a free end 212 that extends radially outward from the mouth portion 208 and helps form the C-shape, as best shown in FIG. 2. In this example, the seal element 200 is disposed in a first annular groove 216 formed in the valve body 104. The first annular groove 216 is formed at a location proximate the fluid inlet 124 and a peripheral edge 220 of the flow control element 156. Accordingly, the seal element 200 is disposed at a location proximate the fluid inlet 124 and the peripheral edge 220 of the flow control element 156. However, in other examples, the seal element 200 can instead take the form of a W-shaped, U-shaped, or Q-shaped seal ring. Figure 2

[0025] The retainer 204 is generally coupled to the valve body 104 to retain the seal element 200 in the first annular groove 216 proximate the fluid passage 136. In this example, the retainer 204 is defined by a generally annular body 224 and a protrusion 228 that extends radially inward from the generally annular body 224. In this example, the annular body 224 is coupled to an outer surface of the valve body 104 such that the annular body 224 is disposed in a second annular groove 232 of the valve body 104 proximate the first annular groove 216. Preferably, the annular body 224 is pressed onto the outer surface of the valve body 104, but can be bolted, threaded, or coupled in a different manner. Thus, at least in this example, the protrusion 228 of the retainer 204 is positioned such that it is at least partially disposed in the first annular groove 216. Accordingly, when the seal element 200 is in the first annular groove 216, the end of the protrusion 228 is disposed proximate the seal element 200, if not engaged with the seal element 200. Moreover, as shown in FIG. 2, the seal element 200 is disposed in the first annular groove 216 such that the mouth portion 208 of the seal element 200 faces the retainer 204 and the free end 212 of the seal element 204 is proximate the end of the protrusion 228, if not engaged with the end of the protrusion 228. Furthermore, the seal element 200 is disposed radially inward of an inner surface 236 of the retainer 204 (the inner surface 236 includes the end of the protrusion 228). Figure 2

[0026] ​​It should be appreciated that, with the flow control element 156 and the retainer 204, the seal element 200 is removably retained in the first annular groove 216 of the valve body 104. In other words, by removing the retainer 204, the seal element 200 can be removed (e.g., after a predetermined number of operating cycles) and repaired or replaced with a different seal element. In some cases, the flow control element 156 also needs to be removed before the seal element 200 is removed, but this is not always the case.

[0027] The rotary valve 100 in this example also includes a first sleeve 250, a second sleeve 252, and a second seal element 254. The first sleeve 250 and the second sleeve 252 are each configured to be disposed between the valve body 104 and the valve stem 152. The first sleeve 250 and the second sleeve 252 each preferably have a hollow, generally cylindrical shape. The first sleeve 250 is disposed in the first central bore 144 of the valve body 104, while the second sleeve 252 is disposed in the second central bore 148 of the valve body 104. Accordingly, the first sleeve 250 and the second sleeve 252 are positioned to receive and surround, respectively, the first portion and the second portion of the valve stem 152 that extend through the valve body 104. In other words, the first sleeve 250 is radially disposed between the interior of the valve body 104 that defines the first central bore 144 and the portion of the valve stem 152 that is disposed in the first sleeve 250, and the second sleeve 252 is radially disposed between the interior of the valve body 104 that defines the second central bore 148 and the portion of the valve stem 152 that is disposed in the second sleeve 252. Thus, the first sleeve 250 and the second sleeve 252 are each configured to radially position the valve stem 152 and the flow control element 156 within (more specifically, at the center of) the valve body 104, thereby improving the shutoff capability of the rotary valve 100. Moreover, the first sleeve 250 and the second sleeve 252 each reduce the frictional forces between the valve stem 152 and the valve body 104, and reduce direct wear on the valve stem 152 and the valve body 104. Meanwhile, the second seal element 254 is configured to provide a seal between the valve body 104 and the retainer 204. In this example, the second seal element 254 takes the form of a gasket that is confined between the inner surfaces 236 of the retainer 204. Thus, the second seal element 254 prevents fluid that flows through the fluid inlet 124 from flowing between the valve body 104 and the retainer 204.

[0028] The rotary valve 100 in this example also includes a packing assembly 258 partially disposed within the first central bore 144 of the valve body 104 to prevent fluid leakage. The packing assembly 258 generally includes a packing ring 262 disposed in a third groove of the valve body 104 adjacent to the first central bore 144, and a packing 266 also disposed within the first central bore 144. The packing assembly 258 generally also includes components for retaining the packing ring 262 and the packing 266 within the first central bore 144, namely, a packing gland 270, a packing nut 274, and a packing stud 278. As is well known in the art, these components can be adjusted to vary the force exerted on the packing 266, thereby varying the seal between the packing 266 and the valve stem 152.

[0029] Although not described or illustrated herein, it should be understood that the rotary valve 100 may include additional components. For example, the rotary valve 100 may include an actuator, such as a mechanical actuator (e.g., a handle), a pneumatic actuator, a hydraulic actuator, an electric actuator, or any other suitable actuator, operably coupled to the valve stem 152 to drive (e.g., rotate) the flow control element 156 between different positions. More specifically, the actuator (not shown) may be configured to rotate the valve stem 152 between the closed position ( Figure 1 and Figure 2 ), a fully open position (not shown), and one or more intermediate open positions (not shown) to control the flow of fluid through the rotary valve 100. It should be understood that in this example, the open position of the flow control element 156 is rotated approximately 180 degrees relative to the closed position. In any case, when the flow control element 156 is in the fully open position (or one of the intermediate open positions), the peripheral edge 220 of the flow control element 156 is spaced apart from the sealing element 200, thereby allowing fluid to flow through the rotary valve 100 (particularly between the fluid inlet 124 and the fluid outlet 132 via the fluid passage 136). Conversely, when the flow control element 156 is in the closed position, the sealing element 200 sealingly engages the peripheral edge 220 of the flow control element 156, thereby closing the rotary valve 100 (and preventing fluid from flowing between the fluid inlet 124 and the fluid outlet 132).

[0030] Alternatively, the rotary valve 100 may be modified to include a biasing member 300 and a coating 304 on the sealing member 200, such as Figure 3 As shown. Figure 3 In the example shown, the biasing element 300 takes the form of an annular spring disposed within the sealing element 200, such that the biasing element 300 is also disposed within the first annular groove 216. However, in other examples, the biasing element 300 may instead be in the form of a different spring, an energizing ring, a Belleville washer, or other suitable biasing element. Figure 3It is also shown that the sealing element 200 has an outer diameter OD, an inner diameter ID, a cross-sectional diameter D B and a thickness T B In any case, when the biasing element 300 is disposed inside the sealing element 200, the biasing element 300 helps to bias the mouth 208 and the free end 212 of the sealing element 200 outwardly away from each other and toward the valve body 104, the flow control element 156, and the retainer 204. In this manner, the biasing element 300 increases the closing force provided by the sealing element 200 against the flow control element 156, thereby providing a tighter shut-off. At the same time, the coating 304 is configured to further improve the shut-off performance of the sealing element 200. To this end, the coating 304 is provided on part or all of the outer surface of the sealing element 200. The coating 304 is preferably made of a noble metal (e.g., gold, silver, copper) or a non-metallic material such as polytetrafluoroethylene (PFTE).

[0031] Furthermore, it should be understood that the rotary valve and components therein described herein can be manufactured using standard manufacturing techniques, such as drilling, machining, punching, and casting. Alternatively, the rotary valve and components therein described herein can be manufactured using additive manufacturing techniques. The additive manufacturing techniques can be any additive manufacturing technique or process that builds a three-dimensional object by adding successive layers of material on a material. The additive manufacturing techniques can be performed by any suitable machine or combination of machines. The additive manufacturing techniques generally involve or use a computer, three-dimensional modeling software (e.g., computer-aided design or CAD software), a machine device, and a layering material. Once a CAD model is generated, the machine device can read data from the CAD file and layers or add successive layers of liquid, powder, sheet material (e.g.), in a layer-by-layer manner to manufacture the three-dimensional object. The additive manufacturing techniques can include any of a variety of techniques or processes, such as a stereolithography (SLA) process, a fused deposition modeling (FDM) process, a multi-jet modeling (MJm) process, a selective laser sintering (SLS) process, an electron beam additive manufacturing process, and an arc welding additive manufacturing process. In some embodiments, the additive manufacturing process can include a directed energy laser deposition process. Such a directed energy laser deposition process can be performed by a multi-axis computer numerical control (CNC) lathe having directed energy laser deposition capabilities.

[0032] Finally, while certain rotary valves and inner assembly components have been described herein in accordance with the teachings of the present disclosure, the scope of the present patent is not so limited. Rather, it will be apparent that, aside from those already described, modifications and improvements can occur to one of ordinary skill in the art upon reading the foregoing description. The present patent encompasses all such modifications and improvements. Accordingly, it is intended to protect all changes and modifications that fall within the scope of the present disclosure.

Claims

1. A trim assembly for a rotary valve, the rotary valve comprising a valve body, the trim assembly comprising: valve stem; a flow control element coupled to the valve stem and adapted to be disposed in the valve body, the flow control element being movable between an open position and a closed position; a sealing element adapted to be disposed in the valve body such that the sealing element is disposed proximate the flow control element, wherein the sealing element sealingly engages the flow control element when the flow control element is in the closed position; as well as a retainer adapted to be coupled to the valve body, the retainer being configured to hold the sealing element in position adjacent the flow control element; The sealing element is made of a metal material and has an opening facing the retainer.

2. The inner component assembly of claim 1, wherein, The sealing element is a C-shaped sealing ring.

3. The inner component assembly of claim 1, wherein, The sealing element is disposed between a peripheral edge of the flow control element and an inner surface of the retainer.

4. The inner component assembly of claim 1, wherein, The sealing element is made entirely of the metallic material.

5. The inner component assembly of claim 1, wherein, Also included is a biasing element disposed at least partially within the interior of the sealing element.

6. A trim assembly for a rotary valve, the rotary valve comprising a valve body, the trim assembly comprising: valve stem; a flow control element coupled to the valve stem and adapted to be disposed in the valve body, the flow control element being movable between an open position and a closed position; a sealing element adapted to be disposed in the valve body such that the sealing element is disposed proximate the flow control element, wherein the sealing element sealingly engages the flow control element when the flow control element is in the closed position; as well as a retainer adapted to be coupled to the valve body, the retainer being configured to hold the sealing element in position adjacent the flow control element; The sealing element is a C-shaped sealing ring made of metal material.

7. The inner component assembly of claim 6, wherein, The C-shaped seal ring has a mouth portion facing the retainer.

8. The inner component assembly of claim 6, wherein, The sealing element is disposed between a peripheral edge of the flow control element and an inner surface of the retainer.

9. The inner component assembly of claim 6, wherein, The sealing element is made entirely of the metallic material.

10. The inner component assembly of claim 6, wherein, Also included is a coating applied to an outer surface of the sealing element.

11. The inner component assembly of claim 6, wherein, Also included is a biasing element disposed at least partially within the interior of the sealing element.

12. A rotary valve comprising: a valve body defining a valve inlet, a valve outlet, and a valve interior in fluid communication with the valve inlet and the valve outlet; a valve stem movably disposed in the central hole of the valve body; a flow control element movably disposed within the valve via the valve stem to control fluid flow between the valve inlet and the valve outlet, the flow control element being movable between an open position and a closed position, wherein the open position allows fluid to flow between the valve inlet and the valve outlet, and the closed position prevents fluid from flowing between the valve inlet and the valve outlet; a sealing element disposed in the recess of the valve body such that the sealing element is disposed proximate the flow control element, wherein the sealing element sealingly engages the flow control element when the flow control element is in the closed position; and a retainer coupled to the valve body and configured to retain the sealing element in the recess of the valve body, wherein the sealing element is a C-shaped seal ring made of a metallic material.

13. The rotary valve of claim 12, wherein, The C-shaped seal ring has a mouth facing the retainer.

14. The rotary valve of claim 12, wherein, Further comprising a sleeve disposed in the valve body and sized to receive and surround a portion of the valve stem.

15. The rotary valve of claim 12, wherein, The retainer is coupled to an outer surface of the valve body.

16. The rotary valve of claim 12, wherein, Further comprising a second sealing element disposed between the retainer and the valve body.

17. The rotary valve of claim 12, wherein, The seal ring is disposed between a peripheral edge of the flow control element and an inner surface of the retainer.

18. The rotary valve of claim 12, wherein, The seal ring is made entirely of the metallic material.

19. The rotary valve of claim 12, wherein, Further comprising a coating applied to an outer surface of the seal ring.

20. The rotary valve of claim 12, wherein, The retainer has an inner surface, and wherein the inner surface is disposed radially outward of the C-shaped seal ring.

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