Expandable gasket

Abstract

An expandable gasket, comprising: a metal body having a first ring-shaped face, a second ring-shaped face, an inner diameter, an outer diameter, and a thickness extending from the first ring-shaped face to the second ring-shaped face; and at least one expandable portion along the metal body for enabling expansion of the inner diameter and the outer diameter of the metal body.

Description

EXPANDABLE GASKETFIELD OF THE INVENTION

[0001] The present disclosure is directed generally to shell-and-tube heat exchanger systems and, more particularly, to an expandable gasket for use in a shell-and-tube heat exchanger.BACKGROUND

[0002] This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, 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 disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.

[0003] Shell-and-tube heat exchangers typically include an outer shell, a bundle of tubes inside the shell that span nearly the entire length of the shell, and a tube sheet that holds the bundle of tubes in place. Such heat exchangers also generally include a metallic gasket positioned between the tube sheet and a flange of the shell.

[0004] Over time, the gaskets may become worn and require replacement. The replacement process generally includes removal of the entire tube bundle from the shell, which can be difficult and require sufficient space adjacent to the heat exchanger for the tube bundle to clear the shell so that the gasket can be fitted around the bundle. Unfortunately, in many settings this space must be made by moving the heat exchanger and / or moving adjacent equipment, which can be costly and time-consuming.

[0005] It is now recognized that a need exists for an expandable gasket to aid in the gasket replacement process.SUMMARY

[0006] A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below.

[0007] In accordance with one or more aspects of the disclosure, an expandable gasket includes: a metal body having a first ring-shaped face, a second ring-shaped face, an inner diameter, an outer diameter, and a thickness extending from the first ring-shaped face to the second ring-shaped face; and at least one expandable portion along the metal body for enabling expansion of the inner diameter and the outer diameter of the metal body. Each expandable portion includes: a first cut formed through the thickness of the metal body and intersecting the outer diameter of the metal body; and a second cut formed through the thickness of the metal body and intersecting the inner diameter of the metal body, wherein the first and second cuts do not intersect one another.

[0008] In accordance with other aspects of the disclosure, a shell and tube heat exchanger includes: an outer shell having a flange; a tube sheet with a bundle of tubes coupled thereto; and a gasket positioned between the tube sheet and the flange of the outer shell. The gasket includes: a metal body having a first ring-shaped face, a second ring-shaped face, an inner diameter, an outer diameter, and a thickness extending from the first ring-shaped face to the second ring-shaped face; and at least one expandable portion along the metal body for enabling expansion of the inner diameter and the outer diameter of the metal body. Each expandable portion includes at least two cuts formed through the thickness of the metal body, and the at least two cuts do not form a continuous leak path between the outer diameter and the inner diameter of the metal body.

[0009] In accordance with other aspects of the disclosure, a method for replacing a gasket of a shell and tube heat exchanger includes providing an expandable gasket, the expandable gasket including: a metal body having a first ring-shaped face, a second ring-shaped face, an inner diameter, an outer diameter, and a thickness extending from the first ring-shaped face to the second ring-shaped face; and at least one expandable portion along the metal body. Each expandable portion includes at least two cuts formed through the thickness of the metal body, wherein the at least two cuts do not intersect each other. The method further includes: expanding the gasket from an unexpanded configuration to an expanded configuration by unfolding the at least one expandable portion of the metal body; moving the gasket in the expanded configuration over a tube sheet of the heat exchanger; returning the gasket to an unexpanded configuration; and securing the gasket in the unexpanded configuration between the tube sheet and a flange on an outer shell of the heat exchanger.BRIEF DESCRIPTION OF DRAWINGS

[0010] The drawings illustrate only example embodiments and are therefore not to be considered limiting in scope, as the example embodiments may admit to other equally effective embodiments. The elements and features shown in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the example embodiments. Additionally, certain dimensions or positions may be exaggerated to help visually convey such principles. In the drawings, reference numerals designate like or corresponding, but not necessarily identical, elements.

[0011] FIG. l is a schematic side view illustrating an example use of an expandable gasket in a shell and tube heat exchanger, in accordance with one or more aspects of the present disclosure.

[0012] FIG. 2 is a schematic front view of an example expandable gasket, in accordance with one or more aspects of the present disclosure.

[0013] FIG. 3 is a perspective view of a portion of an example expandable gasket with cuts to make an expandable portion of the gasket, in accordance with one or more aspects of the present disclosure.

[0014] FIG. 4 is a perspective view of the portion of the expandable gasket of FIG. 3 in an expanded configuration, in accordance with one or more aspects of the present disclosure.

[0015] FIG. 5 is a perspective view of a portion of another example expandable gasket with cuts to make an expandable portion of the gasket, in accordance with one or more aspects of the present disclosure.

[0016] FIG. 6 is a perspective view of the portion of the expandable gasket of FIG. 5 in an expanded configuration, in accordance with one or more aspects of the present disclosure.

[0017] FIG. 7 is a perspective view of a portion of another example expandable gasket with cuts to make an expandable portion of the gasket, in accordance with one or more aspects of the present disclosure.

[0018] FIG. 8 is a perspective view of the portion of the expandable gasket of FIG. 7 in an expanded configuration, in accordance with one or more aspects of the present disclosure.

[0019] FIG. 9 is a perspective view of a portion of another example expandable gasket with cuts to make an expandable portion of the gasket, in accordance with one or more aspects of the present disclosure.

[0020] FIG. 10 is a perspective view of the portion of the expandable gasket of FIG. 9 in an expanded configuration, in accordance with one or more aspects of the present disclosure.

[0021] FIG. 11 is a side view of an example expandable gasket secured between a flange of a heat exchanger shell and a tube sheet, in accordance with one or more aspects of the present disclosure.

[0022] FIG. 12 is a side view of another example expandable gasket secured between a flange of a heat exchanger shell and a tube sheet, in accordance with one or more aspects of the present disclosure.

[0023] FIG. 13 is a process flow diagram illustrating a method for replacing a gasket of a shell and tube heat exchanger, in accordance with one or more aspects of the present disclosure.DETAILED DESCRIPTION OF THE INVENTION

[0024] The present disclosure is directed to expandable gaskets for use in shell and tube heat exchangers. As discussed above, shell and tube heat exchangers typically include a metallic gasket, and over time these gaskets may become worn and require replacement. The current replacement process often necessitates moving the heat exchanger and / or moving adjacent equipment, which can be costly and time-consuming.

[0025] To address these and / or other concerns relating to such gasket replacement, it is now recognized that it would be advantageous to have a gasket that can be expanded over the tube sheet, and returned to its original, unexpanded configuration when placed between the tube sheet and the shell flange. Gaskets are typically made with metal cores that are not flexible enough on their own to expand or stretch over a tube sheet which by its nature usually has a larger diameter than the gasket.

[0026] An example process for replacing a gasket of a shell and tube heat exchanger using the disclosed expandable gasket 100 is shown in FIG. 1. The shell and tube heat exchanger 102 includes an outer shell 104 having a flange 106, a tube sheet 108 with a bundle of tubes 110 coupled thereto, and the expandable gasket 100. When the shell and tube heat exchanger 102 is in operation, the gasket 100 is positioned between the tube sheet 108 and the flange 106 of the outer shell 104. The expandable gasket 100 has at least one expandable portion 112 along its body for enabling expansion of the gasket 100, as shown in FIG. 1.

[0027] The disclosed gasket 100 can be expanded (via expansion of the expandable portion(s) 112) over the tube sheet 108, and returned to its original, unexpanded configuration when placed between the tube sheet 108 and the flange 106 of the outer shell 104. This allows, among other things, gasket replacement to be performed without having to completely remove the bundle of tubes 110 from the outer shell 104 of the heat exchanger 102, thus preventing costly downtime. This in turn allows gasket replacement without relocation of the heatexchanger 102 or adjacent equipment when obstructions are present that interfere with removal of the bundle of tubes 110.

[0028] With reference to FIGS. 1 and 2, the expandable gasket 100 generally includes a metal body 114 having a first ring-shaped face 116, a second ring-shaped face 118, an inner diameter 200, an outer diameter 202, and a thickness 120 extending from the first ring-shaped face 116 to the second ring-shaped face 118. The expandable gasket 100 has at least one expandable portion 112 along the metal body 114 for enabling expansion of the inner diameter 200 and the outer diameter 202 of the metal body 114.

[0029] The at least one expandable portion 112 of the metal body 114 continuously connects adjacent non-expandable portions 122 of the metal body 114 during expansion of the gasket 100. In some embodiments, as shown in FIG. 2 for example, the expandable gasket 100 may have multiple expandable portions 112 along the metal body 114. The multiple expandable portions 112 may be spaced equidistant from each other around the circumference of the gasket 100.

[0030] The expandable gasket 100 may be sized for use with any desired size of heat exchanger 102. For example, the heat exchanger 102 of FIG. 1 may have from a 24 inch diameter to a 60 inch (or larger) diameter. The dimensions of the expandable gasket 100 may be selected specifically to provide desired sealing of a shell and tube heat exchanger 102. As an example, a distance in a radial direction between the inner diameter 200 and the outer diameter 202 of the metal body 114 may be less than or equal to 2 inches, or more particularly less than or equal to 1 inch, or more particularly between ’A inch and 1 inch, or more particularly approximately % inch. Similarly, the thickness 120 of the metal body 114 may be less than or equal to A inch, or more particularly less than or equal to 1 / 8 inch, or more particularly between 1 / 16 inch and 1 / 8 inch.

[0031] In some embodiments, the expandable gasket 100 may be constructed entirely from metal. In this case, the metal body 114 functions as the entire gasket 100. In other embodiments, the expandable gasket 100 may include a coating of filler material disposed over the metal body 114. In this case, the metal body 114 functions as a metal core of the gasket 100. The filler material may be any desired material that is softer than the metal core (114) and configured to move in response to compression of the gasket 100 between surfaces (e.g., flange 106 and tube sheet 108) to fill imperfections in the metal core (114) or the surfaces (106, 108) and thus reinforce the sealing function of the gasket 100. The filler material used for the coating may include, for example, graphite, Teflon® (available from The Chemours Company), vermiculite, or another material having similar properties. The expandable gasket100 may include other materials layered over the metal body 114, with or without the filler material, without departing from the scope of the present disclosure.

[0032] The metal body 114 may be constructed from any desired metal material including, for example, stainless steel (e.g., a 300 series or higher stainless steel). In some embodiments, the metal body 114 may have corrugations on its ring-shaped faces to form a corrugated metal gasket. The corrugations may provide mechanical resilience and help maintain a seal under fluctuating pressure and temperature conditions. In other embodiments, the metal body 114 may have concentric serrations or small grooves on its ring-shaped faces to form a kammprofile gasket. The serrations may provide additional structural integrity to the gasket 100. Any filler material coating on the metal body 114 may have substantially flat, textured, grooved, or corrugated outer surface(s) without departing from the scope of the present disclosure. Example illustrations of expandable gaskets 100 having a metal body 114 and a filler material coating are shown in FIGS. 11 and 12.

[0033] Turning now to FIGS. 3-10, in accordance with embodiments of this disclosure, a gasket 100 (having a metal body 114) has at least one expandable portion 112 (which may be referred to herein as an “expansion joint”). The expansion joint 112 may include, by way of non-limiting example, one or more cuts in the metal body 114 of the gasket 100 as shown in the figures. In particular, each expandable portion 112 of the gasket 100 includes at least two cuts 300 / 500 / 700 / 900 formed through the thickness (120 of FIG. 1) of the metal body 114. These cuts 300 / 500 / 700 / 900 are arranged such that together they do not form a continuous leak path between the outer diameter 202 and the inner diameter 200 of the metal body 114. The cuts 300 / 500 / 700 / 900 may include a first cut intersecting the outer diameter 202 of the metal body 114 and a second cut intersecting the inner diameter 200 of the metal body 114. These first and second cuts may be arranged such that they do not intersect one another, thus preventing any continuous leak path. Each expandable portion 112 of the metal body 114 may continuously connect adjacent non-expandable portions 122 of the metal body 114 during expansion of the gasket 100.

[0034] By way of non-limiting example, the expandable gasket 100 of FIG. 3 includes two cuts 300 A and 300B, where the cuts 300 A and 300B are rotated images of one another and at least partially overlap with one another along the surface (e.g., circumference) of the metal body 114. The cuts 300A and 300B in FIGS. 3 and 4 are each generally L-shaped, and thus each include a first portion 302 and a second portion 304 that are either contiguous or are connected with one another at a corner (e.g., at a right angle). In some embodiments, the first portion 302 of each cut can be considered to run in a generally radial direction of the metalbody 114 (e.g., radially inward from the outer diameter 202, or radially outward from the inner diameter 200), and the second portion 304 in a circumferential direction of the metal body 114, terminating before intersecting a corresponding first portion 302 of the other cut.

[0035] Placing a pulling force outside of the expandable portion 112 in opposite directions generally along the circumference of the gasket 100 (i.e., in opposite directions along the general direction of the second portions 304 of the cuts 300 A and 300B) will cause the gasket 100 to expand, as shown in FIG. 4. In particular, applying such a pulling force to the expandable portion 112 causes the inner diameter 200 and the outer diameter 202 of the metal body 114 to expand so that the gasket 100 can fit around a tube sheet.

[0036] As another example, the expandable gasket 100 of FIG. 5 includes two cuts 500A and 500B, where the cuts 500A and 500B are rotated images of one another and at least partially overlap with one another along the surface (e.g., circumference) of the metal body 114. The cuts 500A and 500B in FIGS. 5 and 6 each include a first portion 502 and a second portion 504 that are either contiguous or are connected with one another by a rounded transition 506. In some embodiments, the first portion 502 of each cut can be considered to begin by running in a generally radial direction of the metal body 114 (e.g., radially inward from the outer diameter 202, or radially outward from the inner diameter 200), and the second portion 504 in a circumferential direction of the metal body 114, terminating before intersecting a corresponding first portion 502 of the other cut. As such, the embodiment of the expandable gasket 100 illustrated in FIG. 5 has a similar configuration to the embodiment of FIG. 3, with the embodiment of FIG. 5 having the rounded transition 506 from the first portion 502 of each cut to the second portion 504 of each cut, rather than a sharp corner. In contrast to the configuration shown in FIG. 3, the first portion 502 of the cuts in FIG. 5 are arc-shaped rather than linear.

[0037] Certain embodiments of the expandable gasket 100 may include more than two cuts, such as in the configurations shown in FIGS. 7-10. In the embodiment of FIG. 7, for example, the expandable gasket 100 includes a first cut 700A, a second cut 700B, and a third cut 700C. The first, second, and third cuts do not intersect one another. The third cut 700C is formed through the thickness (120 of FIG. 1) of the metal body 114, like the first and second cuts. As shown, the third cut 700C does not intersect the inner diameter 200 or the outer diameter 202 of the metal body 114. In FIG. 7, the first and second cuts 700A / B are mirror images of one another, while the third cut 700C partially overlaps both the first and second cuts along the circumferential direction of the gasket 100. In the example configurations of FIGS. 7-10, two of the cuts 700A / B are generally L-shaped while a third cut 700C is generally U-shaped.

[0038] The embodiment of the expandable gasket 100 illustrated in FIG. 9 has a similar configuration to the embodiment of FIG. 7, with the embodiment of FIG. 9 having curved transitions between portions of each cut 900, rather than a sharp corner. That is, the cuts 900A / B / C in the embodiment of FIG. 9 are arc-shaped rather than linear.

[0039] In each of FIGS. 3-10, the material of the metal body 114 and / or the configuration of the expandable portion 112 may be chosen such that the expandable portion 112 will remain in the expanded configuration until forces are placed on the gasket 100 to return it to its unexpanded configuration. Alternatively, the material of the metal body 114 and / or the configuration of the expandable portion 112 may be chosen such that the expandable portion 112 has a spring force that returns the expandable gasket 100 to its unexpanded configuration when the pulling forces are removed from the gasket 100.

[0040] In certain embodiments, adding an expandable portion 112 by making cuts like those shown herein provides a means of expanding the gasket 100 temporarily by “unfolding it,” as shown in FIGS. 4, 6, 8, and 10. The gasket 100 would be folded back into its original shape (e.g., a ring shape) before heat exchanger assembly. In a general sense, the cuts create an ability to expand the gasket’s diameter for installation.

[0041] Since none of the groups of cuts in FIGS. 3-10 intersect one another, there is no full leak path formed between the inner diameter 200 and the outer diameter 202 of the metal body 114. This provides improved sealing at the interface between the shell flange and the tube sheet when the gasket 100 has been folded back to its original shape and secured between the shell flange and the tube sheet. The cuts in the expandable metal body 114 provide a means for expansion of the gasket 100, not a complete separation of the gasket 100 around its circumference.

[0042] In some embodiments, the gasket 100 need only be partially expanded (compared to a complete expansion available through the expandable portion(s) 112) to fit over the tube sheet. For example, the at least one expandable portion 112 of the gasket 100 and its corresponding cuts may be sized such that, if each expandable portion 112 of the gasket 100 were expanded to approximately 1 / 3 of its maximum (i.e., full, complete) expanded length, then the expanded inner diameter 200 of the metal body 114 would be greater than an outer diameter of the tube sheet. In such a case, an operator would only have to open the expandable portion(s) 112 approximately one third of the distance that they can open. This helps to mitigate or prevent kinking of the metal body 114 while it is unfolded, since kinking of the metal body 114 could interfere with re-positioning the gasket 100 into its unexpanded sealing configuration. In embodiments where the gasket 100 has multiple expandable portions 112, it may be desirableto partially expand each expandable portion 112 to about the same position for placement of the gasket 100 over the tube sheet, rather than expanding any single expandable portion 112 to its maximum expanded length.

[0043] As discussed above, the expandable gasket 100 may include a coating of filler material disposed over at least a portion of the metal body 114. FIGS. 11 and 12 illustrate two examples of an expandable gasket 100 having a filler material coating at least a portion of the metal body 114. FIGS. 11 and 12 schematically illustrate the expandable gasket 100 positioned between a flange 106 and a tube sheet 108 of a heat exchanger. This is the position of the gasket 100 after it has been expanded, placed around the tube sheet 108, and then re-shaped back to its unexpanded configuration.

[0044] The views in FIGS. 11 and 12 are meant to be side views showing the outer diameter of the metal body 114. A bracket in the figures indicates the location of an expandable portion 112 of the metal body 114, and in this expandable portion 112 a cut 1100 is shown extending through the thickness of the metal body 114. This cut 1100 is one of at least two cuts forming the expandable portion 112 of the metal body 114, although the other cuts are not visible from this point of view. The drawing is not shown to scale; the metal body 114, filler material coatings, and expandable portion 112 are enlarged for ease of visualization. As illustrated, the gasket 100 has filler material coated on both ring-shaped faces of the metal body 114. In some embodiments, the gasket 100 may also include filler material coating the outer diameter, the inner diameter, or both, of the metal body 114.

[0045] In some embodiments, the coating of filler material may be applied to the metal body 114 to form the expandable gasket 100 prior to any expansion of the gasket 100. Such an example is shown in FIG. 11. As shown, a coating of filler material 1102 is disposed on both non-expandable portions 122 of the metal body 114 and the at least one expandable portion 112 of the metal body 114. The multiple cuts (cut 1100 is visible in FIG. 11) that form the expandable portion 112 extend through both the coating 1102 and the metal body 114. As such, when the gasket 100 was in the expanded position for placing the gasket 100 over the tube sheet 108, the coating 1102 was expanded along with the metal body 114.

[0046] In other embodiments, a portion of the coating of filler material may be applied to the metal body 114 for sealing after the expansion and later returning of the gasket 100 to its unexpanded configuration. Such an example is shown in FIG. 12. As shown, a coating of filler material 1202 is disposed on the non-expandable portions 122 of the metal body 114 and not on the at least one expandable portion 112 of the metal body 114. As such, the multiple cuts (cut 1100 is visible in FIG. 12) that form the expandable portion 112 do not extend through thecoating 1202. As such, when the gasket 100 was in the expanded position for placing the gasket 100 over the tube sheet, the coating 1202 was not expanded along with the metal body 114. After the gasket 100 is returned to its unexpanded configuration, as shown in FIG. 12, additional filler material 1204 is coated over the expandable portion 112 of the metal body 114, essentially patching the outer surface(s) of the metal body 114 where the metal body 114 had previously been expanded. In some embodiments, the filler material 1204 may be applied to this portion via a layer of filler material tape that is placed over the expandable portion 112 of the metal body 114.

[0047] In both FIGS. 11 and 12, the filler material in the coating(s) (1102, 1202, 1204) may be configured to move or flow in response to pressure as the gasket 100 is squeezed between the flange 106 and the tube sheet 108. The moving or flowing filler material may fill in cuts (e.g., 1100) in the metal body 114, as well as any imperfections, deformations, dents, scratches, etc. in the metal body 114, flange 106, and / or tube sheet 108, thereby improving the sealing performance of the gasket 100.

[0048] FIG. 13 is a process flow diagram illustrating an example method 1300 for replacing a gasket of a shell and tube heat exchanger, in accordance with an embodiment of the present disclosure. It should be noted that certain steps of the illustrated method may be performed in a different order than illustrated or may be omitted from the method. In addition, in some embodiments other steps not illustrated in FIG. 13 may be performed in the method 1300.

[0049] At block 1302, the method 1300 includes providing an expandable gasket. The expandable gasket includes a metal body having a first ring-shaped face, a second ring-shaped face, an inner diameter, an outer diameter, and a thickness extending from the first ring-shaped face to the second ring-shaped face. The expandable gasket also includes at least one expandable portion along the metal body. Each expandable portion includes at least two cuts formed through the thickness of the metal body, and the at least two cuts do not intersect each other. In some embodiments, the expandable gasket may also include one or more coatings on the metal body, such as a coating of filler material on at least a portion of the ring-shaped faces of the metal body. The coating of filler material may be located on non-expandable portions of the metal body only, or on both non-expandable portions and expandable portions of the metal body.

[0050] At block 1304, the method 1300 includes expanding the gasket from an unexpanded configuration to an expanded configuration by unfolding the at least one expandable portion of the metal body. Expanding (1304) the gasket may include unfolding each expandable portion of the metal body to approximately 1 / 3 of its complete expanded length. At block 1306, themethod 1300 includes moving the gasket in the expanded configuration over a tube sheet of the heat exchanger. At block 1308, the method 1300 includes returning the gasket to an unexpanded configuration. Optionally, at block 1310, the method 1300 may include adding a coating of filler material to the at least one expandable portion of the metal body after returning the gasket to the unexpanded configuration. Optionally, at block 1312, the method 1300 may include attaching the gasket in the unexpanded configuration to the tube sheet and / or to a flange on an outer shell of the heat exchanger via adhesive. The adhesive may be applied as a spray adhesive to the gasket and then the gasket attached to the tube sheet and / or to the flange, after which the tube sheet and flange can be bolted together. At block 1314, the method 1300 includes securing the gasket in the unexpanded configuration between the tube sheet and the flange on an outer shell of the heat exchanger.

[0051] It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplifications of example embodiments. For example, the functions described above and implemented as the best mode for operating the present invention are for illustration purposes only. Other arrangements and methods may be implemented by those skilled in the art without departing from the scope and spirit of this invention. Moreover, those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

Claims

CLAIMSWhat is claimed is:

1. An expandable gasket, comprising: a metal body having a first ring-shaped face, a second ring-shaped face, an inner diameter, an outer diameter, and a thickness extending from the first ring-shaped face to the second ring-shaped face; and at least one expandable portion along the metal body for enabling expansion of the inner diameter and the outer diameter of the metal body, wherein each expandable portion comprises: a first cut formed through the thickness of the metal body and intersecting the outer diameter of the metal body; and a second cut formed through the thickness of the metal body and intersecting the inner diameter of the metal body, wherein the first and second cuts do not intersect one another.

2. The expandable gasket of claim 1, wherein the at least one expandable portion of the metal body continuously connects adjacent non-expandable portions of the metal body during expansion of the gasket.

3. The expandable gasket of claim 1, further comprising a coating of filler material disposed over at least a portion of the metal body.

4. The expandable gasket of claim 3, wherein the coating is disposed on non-expandable portions of the metal body and not on the at least one expandable portion of the metal body.

5. The expandable gasket of claim 3, wherein the coating is disposed on both non- expandable portions of the metal body and the at least one expandable portion of the metal body, wherein the first and second cuts at each expandable portion extend through the coating and the metal body.

6. The expandable gasket of claim 1, comprising multiple expandable portions along the metal body, the expandable portions being spaced equidistant from each other around the circumference of the gasket.

7. The expandable gasket of claim 1, wherein the first cut and the second cut are each L- shaped cuts having two portions connected at a corner.

8. The expandable gasket of claim 1, wherein the first cut and the second cut each have two portions connected by a rounded transition.

9. The expandable gasket of claim 1, wherein each expandable portion further comprises a third cut formed through the thickness of the metal body and not intersecting the outer diameter or the inner diameter of the metal body, wherein the first, second, and third cuts do not intersect one another.

10. The expandable gasket of claim 1, wherein: a distance in a radial direction between the inner diameter and the outer diameter is less than or equal to 2 inches; and a thickness of the metal body is less than or equal to 0.25 inch.

11. A shell and tube heat exchanger, comprising: an outer shell having a flange; a tube sheet with a bundle of tubes coupled thereto; and a gasket positioned between the tube sheet and the flange of the outer shell, wherein the gasket comprises: a metal body having a first ring-shaped face, a second ring-shaped face, an inner diameter, an outer diameter, and a thickness extending from the first ring-shaped face to the second ring-shaped face; and at least one expandable portion along the metal body for enabling expansion of the inner diameter and the outer diameter of the metal body, wherein each expandable portion comprises at least two cuts formed through the thickness of the metal body, wherein the at least two cuts do not form a continuous leak path between the outer diameter and the inner diameter of the metal body.

12. The shell and tube heat exchanger of claim 11, wherein the at least two cuts comprise: a first cut intersecting the outer diameter of the metal body; anda second cut intersecting the inner diameter of the metal body, wherein the first and second cuts do not intersect one another.

13. The shell and tube heat exchanger of claim 12, wherein the at least two cuts further comprises a third cut that does not intersect the inner diameter or the outer diameter of the metal body.

14. The shell and tube heat exchanger of claim 11, wherein the at least one expandable portion and its corresponding cuts are sized such that, if each expandable portion is expanded to approximately 1 / 3 of its complete expanded length, the expanded inner diameter of the metal body is greater than an outer diameter of the tube sheet.

15. The shell and tube heat exchanger of claim 11, wherein the gasket further comprises a coating of filler material disposed over the at least one expandable portion of the metal body, wherein the at least two cuts at each expandable portion do not extend through the coating.

16. The shell and tube heat exchanger of claim 11, wherein the gasket further comprises a coating disposed on the at least one expandable portion of the metal body, wherein the at least two cuts at each expandable portion extend through the coating and the metal body.

17. A method for replacing a gasket of a shell and tube heat exchanger, the method comprising: providing an expandable gasket, comprising: a metal body having a first ring-shaped face, a second ring-shaped face, an inner diameter, an outer diameter, and a thickness extending from the first ring-shaped face to the second ring-shaped face; and at least one expandable portion along the metal body, each expandable portion comprising at least two cuts formed through the thickness of the metal body, wherein the at least two cuts do not intersect each other; expanding the gasket from an unexpanded configuration to an expanded configuration by unfolding the at least one expandable portion of the metal body; moving the gasket in the expanded configuration over a tube sheet of the heat exchanger; returning the gasket to an unexpanded configuration; andsecuring the gasket in the unexpanded configuration between the tube sheet and a flange on an outer shell of the heat exchanger.

18. The method of claim 17, further comprising adding a coating of filler material to the at least one expandable portion of the metal body after returning the gasket to the unexpanded configuration and prior to securing the gasket between the tube sheet and the flange.

19. The method of claim 17, further comprising attaching the gasket in the unexpanded configuration to the tube sheet and / or the flange via adhesive.

20. The method of claim 17, wherein expanding the gasket comprises unfolding each expandable portion of the metal body to approximately 1 / 3 of its complete expanded length.

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