Valve bellows configured for valve

Abstract

A bellows is configured for use on a valve. These configurations may include a hollow corrugated section to receive a valve stem therethrough. At its end, the corrugated section may terminate at the adapter. In one implementation, additive manufacturing may configure the bellows as a single or integral unit, thereby avoiding weldments or fasteners that may complicate the manufacturing of the parts. This technique may create an interface between the corrugated section and the adapter, the interface comprising the same material as an adjacent part.

Description

BACKGROUND OF THE INVENTION

[0001] Flow controls play an important role in many industrial facilities. For example, power plants and industrial process facilities use different types of flow controls to manage the flow of materials (usually fluids) throughout a vast network of pipes, tanks, generators, and other equipment. Control valves can be used to precisely regulate the flow to meet process parameters. These devices can include parts that prevent the working fluid from leaking into the atmosphere. These parts typically allow relative movement, which can complicate their ability to seal against other parts to close any flow paths that might allow the working fluid to escape the device. SUMMARY OF THE INVENTION

[0002] The subject matter of the present disclosure relates to improvements in the construction of these preventive measures. Of particular interest are embodiments that integrate parts in a manner that both simplifies assembly and improves functionality to reduce or prevent emissions. These embodiments can result in a hermetically sealed enclosure that is capable of containing accidental or "fugitive" emissions. This feature improves safety as it largely prevents the escape of gases or vapors that can be potentially hazardous to workers in the vicinity of control valves and similar flow controls. An additional benefit is the reduction of product loss, which can allow the operator to maintain productivity and increase revenue. BRIEF DESCRIPTION OF THE DRAWINGS

[0003] This specification refers to the following drawings:

[0004] Figure 1 A schematic diagram depicting one embodiment of a bellows;

[0005] Figure 2 Depicting Figure 1 A front view of a cross-section of an example of a bellows;

[0006] Figure 3 Depicting Figure 1 A front view of an example of a bellows;

[0007] Figure 4 Depicting Figure 1 A front view of a cross-section of an example of a bellows;

[0008] Figure 5 Depicting Figure 1 A front view of a cross-section of an example of a bellows; and

[0009] Figure 6 A front view of a cross-section of an example of a flow control.

[0010] These figures and any description in this document represent examples that can disclose or explain the invention. These examples include the best mode and also enable any person skilled in the art to practice the invention, including manufacturing and using any device or system and performing any combined method. Unless otherwise stated in the discussion, the figures are not drawn to scale. Elements in the examples may appear in one or more of several views or in combinations of several views. The figures may use similar reference numerals to denote the same or corresponding elements. The methods are merely exemplary and may be modified, for example, by reordering, adding, deleting, and / or changing individual steps or stages. This specification may use the singular words "a" or "an" to identify such stages and any parts, components, elements, or functions; however, this should not exclude the plural form of any such name, unless the specification explicitly recites or states such an exclusion. Similarly, any reference to "one embodiment" or "one specific implementation" does not exclude the existence of other embodiments or specific implementations that also incorporate the described features. Detailed Description

[0011] The features of the examples shown in the above figures will now be discussed. These examples address the problem of bellows seals. These seals prevent fugitive emissions as they can seal around parts that move within a valve. As described herein, the proposed design is assembled into a valve without the need for post-welded parts (or similar mechanical fasteners). Other embodiments are within the scope of this disclosure.

[0012] Figure 1 An example of a valve bellows 100 is depicted. This example exists within a distribution network 102, which is generally designed to transport a substance 104 through a network of conduits 106. The network 102 may include a flow control 108 having a valve positioner 110 and a valve body 112 to connect the device in series with the conduit 106. The valve body 112 may house a valve mechanism, shown here as including a valve seat 114 and a closure member 116. An actuator 118 may be coupled to the closure member 116 via a valve stem 120. In one specific implementation, the valve bellows 100 may include a bellows 122 that encapsulates the valve stem 120.

[0013] Broadly, the valve bellows 100 may be configured to prevent leakage. These configurations may include devices that are capable of deflecting and expanding in response to a load. These devices may employ a construction that is compatible with high temperatures or high pressures, which are common conditions in oil and gas applications. As described herein, the proposed design does not require welded parts or external separate fasteners to prevent the flow of fugitive emissions.

[0014] The distribution system 102 can be configured to convey or move resources. These configurations can be embodied as vast infrastructure. The material 104 can also include gases, liquids, solids, or mixtures. These materials can flow through the system 102 at various pressures and temperatures. The conduit 106 can include pipes or pipelines that are often connected to pumps, compressors, vessels, boilers, etc. The pipeline can also be connected to tanks or reservoirs. In many facilities, this equipment forms a complex network.

[0015] The flow control 108 can be configured to regulate the flow of the material 104 through the conduit 106. These configurations can be embodied as control valves and similar devices. The valve positioner 110 can be configured to process and generate signals. These configurations can be connected to a control network (or "distributed control system" or "DCS") that maintains the operation of all devices on the process pipeline to ensure that the material flows according to the process. The DCS can generate control signals with operating parameters that describe or define the operation of the flow control 108 for this purpose. The valve positioner 110 can have operating hardware such as electrical components and computing components (e.g., processors, memories, executable instructions, etc.). These components can also include electro-pneumatic devices that operate on an input pneumatic supply signal to deliver a control signal at a pressure (usually compressed air) that ensures the flow control 108 supplies the material 104 downstream according to the process parameters.

[0016] The parts of the flow control 108 can be configured to regulate the flow of the material 104 through the conduit 106. The valve body 112 can adopt a structure usually made of cast or machined metal. This structure can form flanges at the openings I, O. Adjacent conduits 106 can be connected to these flanges. The valve mechanisms 114, 116 help regulate the flow. The actuator 118 can be embodied as a pneumatic device. A compressed air signal from the valve positioner 110 can energize this device to generate a load. The valve stem 120 can be embodied as an elongated cylinder or rod that guides this load to the valve mechanisms 114, 116. This feature helps position the closure member 116 (usually a "plug" made of metal or metal alloy) relative to the valve seat 114 at a desired position. This desired position or "set point" can correspond to the flow parameters of the material 104 to meet the process requirements or parameters. The plug 116 can move relative to the valve seat 114 to meet or reach the set point. The movement is usually along the axis of the valve seat 114, or "up" or "down" for those valves oriented vertically on the process line. As noted, the position of the plug 120 can directly correspond to the flow rate of natural gas (or other resources) flowing through the valve seat 118 (or from its upstream side to its downstream side).

[0017] The bellows 122 can be configured to prevent the material 104 from flowing out of the flow control device 108. These configurations can include means capable of transmitting axial movement. These means can expand or contract, for example, in response to the movement of the valve stem 120 (or the plug 116). In a specific embodiment, the means can form a hollow continuous convoluted tube. Its construction can include a flexible or extensible material. The surface "convolutions" or "corrugations" can help absorb any deflections in response to the movement of the plug 120. These features can minimize the stress in the device, which in turn extends the service life. As described herein, the construction can be integrated with other parts in the flow control device 108 for mounting or fixing the bellows 122, instead of welds or fasteners. This feature avoids internal connections that may fail over time. Welds can also complicate the assembly, which may increase the delivery cycle or labor and material costs.

[0018] Figure 2 , Figure 3 and Figure 4 depicts an exemplary structure of the bellows 122. The structure includes a collapsible section 124 around the valve stem 118. The collapsible section 124 can include a thin wall 126 preferably made of metal or a similar material. The thin wall 126 can have a geometry that allows the structure to deflect or expand under load, preferably deflect or expand axially along the longitudinal axis C. The geometry can form corrugations R or regions of alternating ridges and grooves. Additive manufacturing techniques (such as "3D printing") can also be used to expand the breadth of shapes available for this geometry. It can be shown useful to provide a thin wall 126 with angles, curves, shapes, bends, or similar geometries, for example, which can reduce stress or other inherent conditions that may lead to service failures. Combinations of shapes can also be common. As Figure 3 best shown in, the geometry can adopt an angled shape S, although other shapes such as squares, rectangles, or diamonds can also be used. Figure 4 shows a structure having a pair of thin walls 126 that overlap each other to form an embedded wall or "laminated" construction. Each wall 126 can form a cylinder around the longitudinal axis C. As shown, the first or "outer" cylinder can surround the second or "inner" cylinder. This feature effectively embeds the two pieces together, with at least a portion of each piece overlapping each other.

[0019] Figure 5Also depicted is a front view of a cross-section of an exemplary structure of the bellows 122. The thin wall 126 may be connected to the adapter 128 at either end. The interface 130 may couple these two parts together. The interface 130 may be "seamless", or substantially configured with the same material as the adjacent parts 126, 128. A homogeneous material structure may form the parts 126, 128 into a single or "integral" unit. This feature is useful because it avoids welded joints or external separate fasteners. Additive manufacturing techniques (such as "3D printing") may also prove useful for such a construction solution. The "lower" adapter 134 may have a tapered section 136. At the other end, the "upper" adapter 138 may include a shoulder 140, in which a groove 142 is provided. The counterbore 144 may penetrate one side of the adapter 138 to receive the bushing 146.

[0020] Figure 6 Depicted is a front view of a cross-section of an exemplary structure of the flow control 108. The units 126, 128 may be located inside the extension 148 that couples the valve cover 150 to the valve body 112. Fasteners (F), such as nuts or bolts, may be used for this purpose. As shown, the parts 148, 150 may clamp the shoulder 140. The washer 152 may be inserted into the groove 138 and also be located below the shoulder 140. This arrangement seals the gap G between the thin wall 126 and the interior of the extension 148. In a specific embodiment, the packing 154 may be located in the valve cover 150. The construction of the packing 154 helps to allow the valve stem 120 to move, but prevents the flow control 108 from discharging fugitive emissions.

[0021] In view of the foregoing, the improvements herein simplify the construction of the control valve. These embodiments use an integral single part, which avoids the need for welded joints (or fasteners) to create a bellows seal. This feature may reduce the manufacturing cost, as it avoids the need for certain secondary operations (such as welding) or labor. As an additional benefit, the manufacturer may achieve a shorter delivery cycle, as the number of manufacturing steps or processes is fewer.

[0022] The following examples include certain elements or clauses that describe embodiments contemplated within the scope of this specification. These elements may be combined with other elements and clauses to further describe the embodiments. This specification may include and contemplate other examples that occur to those skilled in the art. If these other examples have structural elements that are identical to the literal language of the claims, or if they include equivalent structural elements that are not materially different from the literal language of the claims, then these other examples fall within the scope of the claims.

Claims

1. A valve, comprising: Valve stem; A bellows surrounds the valve stem, the bellows including a flexible section terminating at either end at an adapter, the flexible section and the adapter being integrally formed so as to have a homogeneous material structure throughout the bellows.

2. The valve according to claim 1, further comprising: A bushing is disposed in one of the adapters.

3. The valve according to claim 1, further comprising: An extension portion forms a hollow tube surrounding the bellows.

4. The valve according to claim 1, further comprising: an extension forming a hollow tube surrounding the bellows; and A valve cover is disposed on one end of the extension to clamp one of the adapters therebetween.

5. The valve of claim 1, wherein an end of the flexible section and one of the adapters form a seamless interface.

6. The valve according to claim 1, wherein both ends of the flexible section and the adapter form a seamless interface.

7. The valve of claim 1, wherein the flexible section and the adapter have the same material composition.

8. The valve of claim 1, wherein the flexible section and the adapter have a homogeneous composition therebetween.

9. The valve of claim 1, wherein the flexible section and the adapter are connected to each other without welds.

10. The valve of claim 1, wherein the flexible section and the adapter are connected to each other without welds or external separate fasteners.

11. A valve, comprising: Valve stem; A bellows surrounds the valve stem, the bellows being integrally formed at either end with a pair of adapters coupled to the valve stem.

12. The valve according to claim 11, wherein the bellows has a corrugated thin wall.

13. The valve of claim 11, wherein the bellows has a thin wall with a groove that allows the thin wall to deflect along its longitudinal axis.

14. The valve of claim 11, wherein the bellows has a thin wall having an angled shape that allows the thin wall to deflect along its longitudinal axis.

15. The valve of claim 11, wherein the bellows has a thin wall having a same material composition as the adapter.

16. The valve according to claim 11, wherein the bellows has a pair of thin walls overlapping each other.

17. The valve of claim 11, wherein the bellows has a first wall forming a first cylinder and a second wall forming a second cylinder, the second cylinder being located inside the first cylinder.

18. The valve of claim 11, wherein the bellows has a first wall forming a first cylinder and a second wall forming a second cylinder, the second cylinder being located inside and integral with the first cylinder.

19. The valve of claim 11, wherein the bellows and the adapter are connected to each other without welds.

20. The valve of claim 11, wherein the bellows and the adapter are connected to each other without welds or external separate fasteners.

Images