SEAL DEVICE HAVING AN INNER DIAMETER SEAL

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

[0001] This application claims priority from U.S. Provisional Patent Application No.

60/935,746 entitled "Seal Device," by T. Scott Tanner, filed on August 29, 2007, which Provisional Patent Application is hereby incorporated by reference in its entirety.

BACKGROUND

[0002] Seal devices have been used in a variety of applications to prevent fluid from leaking between joined components. For example, a seal device may be interposed and compressed between flanged end-connections of a flow line where in-line process control equipment is installed. In-line process control equipment includes valves, pumps, flow meters, temperature and pressure controllers and the like. This equipment usually cannot be welded into the flow line because time-scheduled maintenance requires temporary removal of this equipment and, occasionally, depleted equipment must be removed for replacement. In-line process control equipment is used in a variety of industries such as the chemical industry for processing, transporting and dispensing a myriad of chemicals and chemical compounds as well as the oil and gas industry for recovering, distributing and processing oil, gas and by-products thereof

[0003] There are several reasons why the efficacy of a seal device is important to the user. First, failure of the seal device could cause significant environmental damage Second, a high capital investment is typically associated with transporting fluids through a flow line system and leakage of the fluid must be prevented to protect this expensive system from potential damage. Third, a high labor cost is often associated with repair of a damaged flow line system. Numerous problems cause seal devices to leak. Such problems include corrosion, over- torqueing, under-torqueing, temperature, pressure and velocity of the fluid, to name a few.

[0004] Most any fluid can be considered corrosive. For example, even water might be considered slightly corrosive if its pH deviates from 7.0; hydrochloric acid having a low pH and hydrogen peroxide having a high pH might be considered highly corrosive. Occasionally, the

materials used to fabricate seal devices are not compatible with the corrosive nature of the fluid contained in the flow line. Corrosion causes the seal device to deteriorate and, unless it is timely replaced, fluid leakage or subsequent seal blow-out can occur. Also, the temperature and pressure of the corrosive fluid could accelerate the rate by which the seal device deteriorates. Sometimes a single flow line is used to transport two or more types of fluids at different times. The material used to fabricate the seal device might be compatible with one type of fluid but not the other. Thus, one fluid could cause the seal device to corrode and, subsequently, fail .

[0005] To compress the seal device between the flanged end-connections of the joined pieces in the flow line, fasteners, such as a common nut and bolt combination, are often used. Although installation instructions of a particular seal device might include specific torque requirements for proper sealing, an installer still might apply too much torque or too little torque. It is also possible that even if the correct range of torque is applied to the fasteners, the amount of compression force is distributed unevenly around the seal device. When compressed, the seal device then may not deform in a uniform manner. Thus, improper lorqueing of the fasteners to compress the seal device may result in leakage of the fluid from the flow line.

[0006] Particularly in industrial applications, a seal device is not recommended for re-use after it has been removed from operations. This is due to the fact that the material used to fabricate the seal device deforms when it is compressed between the joined pieces in a flow line. The material deforms within its modulus of elasticity during operations but does not recover fully thereafter. If this used seal device is placed back into operation, it is possible that further compression of it will extend beyond its modulus of elasticity thus destroying its sealing capabilities.

[0007] Furthermore, during operations, the seal device is acted upon by the hydrodynamic and hydrostatic forces exerted by the fluid. Generally, such forces act on commonly known seal devices in a manner that cause the seal device to expand radially outwardly, that is, in the plane of the flanges. Little, if any, of these forces is directed towards improving the sealing characteristics of the seal device.

[0008] It is possible in some applications that the temperature and/or the pressure of the fluid might fluctuate throughout a range. Temperature and/or pressure fluctuations can cause thermal and mechanical expansion and contraction of the material comprising the seal device. Unless the material chosen for fabrication of the seal device has been selected with these design considerations in mind, it is possible that the sealing device could lose its sealing capabilities due to material fatigue caused by numerous cycles of thermal and mechanical expansion and contraction.

[0009] Given the problems in seal devices as stated above, a need exists to improve seal technology. It would be advantageous if an improved seal device could be designed for improved sealing capability by utilizing the hydrodynamic and hydrostatic forces of the fluid contained in the flow line. It would also be advantageous if the sealing device could be fabricated from corrosion resistant materials which could resist corrosion in a highly corrosive environment. Another need in the current seal technology would be to provide a seal device that is less sensitive to exacting torqυeing requirements so that there is no effect upon the performance of the seal device as a result thereof. Another need would be to provide a seal device that can be reused even though it has been used in prior operations

[0010] Another need would be to provide an improved seal device that would be generally insensitive to expansion and contraction cycles due to fluctuations in temperature and/or pressure. Another need would be to produce a seal device which would be compatible with a variety of fluids regardless of their corrosive nature, temperature and or pressure. The present technology is directed to such an improved seal device

[0011] One such solution to these problems is outlined in U.S. Patent No. 5,518,257, entitled "Seal Device for Flow Line Applications", (hereinafter, " the '257 patent"). The '257 patent relates to a seal device comprising an inner seal member and an outer seal retainer member surrounding the inner seal member The inner seal member has a central opening extending therethrough to accommodate the flow of the fluid and has a channel structure that provides a channel opening that faces the central opening and extends therearound. Two lips are disposed opposite each other and extend around an inner peripheral portion of the inner seal

member. The lips operate to apply a sealing force against the joined components when interposed and compressed therebetween. The inner seal member is operative to prevent contact of the fluid with the outer seal retainer member when interposed and compressed between the joined pieces.

[0012] The '257 patent further discloses the use of elastomeiic energizing elements, which, in certain applications, will limit the usefulness of the seal device. First, this limits the temperature rating of the gasket. Second, all elastomers are subject to the phenomenon known as compression set. This phenomenon is the loss of resiliency and conformance to the original shape of the material. For this reason, the gasket in the 257 patent would be limited in temperature and would tend to lose its ability to compensate for cyclical operating conditions when compared to the current technology.

[0013] Further, in the '257 patent, the energizing element is used to provide support to the seal member to force expansion into the sealing faces. While this provides benefit in that the sealing faces receive additional sealing force from the energizing element, there are other areas of the seal which would benefit more from this additional sealing force. For example, it may be desirable to provide an additional sealing force to a point radially outward of the sealing lips toward the outer diameter of the seal element.

SUMMARY

[0014] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary, and the foregoing Background, are not intended to identify key aspects or essential aspects of the claimed subject matter. Moreover, this Summary is not intended for use as an aid in determining the scope of the claimed subject matter.

[0015] In a first aspect of the present technology, a seal device is provided for placement between opposing components, such as the flanged-end connections of adjacent pipe sections. In various embodiments, the seal device includes an annular seal member having: (i) first and second generally opposite sealing faces, (ii) an inner radius defining a central aperture, (iii) an

outer radius defining a radially outer edge of the seal member, (iv) a radial inner channel that is positioned between the two faces and open to the central aperture, and (v) a radially outer groove that is open to the radial outer edge of the seal member. The seal member may be formed from compressible materials suitable for sealing fluids such as: elastomers, metals, resins, and polymers such as polyetheretherketone, perfluorelastomers, and polytetrafluoroethylene Many embodiments of the seal device provide a seal retainer that surrounds the seal member. In some embodiments, the seal retainer is sized to engage and extend at least partially into the radial outer groove on the seal member.

[0016] In some embodiments, the seal retainer is at least partially coated with one or more corrosion-resistant materials, such as glass reinforced epoxy or a high temperature thermoplastic. The seal retainer further includes a corrosion-resistant core that, in some embodiments, is formed from stainless steel. In some embodiments, the seal retainer provides a support for one or more heat and fire-resistant secondary seals. In various embodiments, the secondary seals may be formed to include one or more heat-resistant materials, such as graphite; asbestos; ceramic compounds; or other similar material. In other embodiments, the secondary seals are formed to include fire-resistant materials, which include various metal and metal alloys.

[0017] In other embodiments, the seal member is depicted with a pressure/spring energized configuration. In an exemplary embodiment, the seal member is provided with a pair of J-shaped cuts that form a pair of radial face seals Coil springs may be disposed within the J- shaped grooves to provide positive spring energy to the face seals and enhance the sealing engagement between the radial face seals and the sealing surfaces of adjacent structures, such as the flange faces of pipe sections. The seal member may be formed from compressible materials suitable for sealing fluids such as: elastomers, metals, resins, and polymers such as polyetheretherketone, perfluorelastomers, and polytetrafluoroethylene.

[0018] In another embodiment of the present technology, the thickness of the seal member is greater than the thickness of said seal retainer when the seal is in a relaxed state, and the thickness of the seal member is equal to the thickness of the seal retainer when the seal and retainer are compressed between two flanges

[0019] In another preferred embodiment of the present technology, the seal member comprises an elastomeric extrusion. More preferably, the seal member comprises a corrosion- resistant material Most preferably, the corrosion-resistant material is selected from a group consisting of polymers, polyetheretherketone. perfluorelastomers, polytetrafluorethylene. The seal retainer member is preferably fabricated from a rigid material.

[0020] In yet another embodiment of the present technology, the seal member further comprises two sealing lips formed form the portion of the seal retainer between the radially inner channel and the first sealing face and the radially inner channel and the second sealing face. In one aspect of the present technology, the sealing lips are shaped to provide the radially inner channel with a rectangular cross sectional shape. In other embodiments of the present technology, the sealing lips are shaped to provide the radially inner channel with triangular, parabolic, or trapezoidal cross sectional shapes.

[0021] In some embodiments of the present technology, the sealing force is at least partially supplied through the interaction of a pressurized fluid acting on the interior surfaces of the flange within the radially inner channel. In another embodiment of the present technology, the sealing force increases as the pressure supplied by the pressurized fluid increases within the radially inner channel. Accordingly, embodiments of the present technology provide a seal that maintains good sealing properties even where relatively low face loads are applied.

[0022] Thus, there has been outlined, rather broadly, the more important features of the technology in order that the detailed description that follows may be better understood and in order that the present contribution to the art may be better appreciated. There are, obviously, additional features of the technology that will be described hereinafter and which will form the subject matter of the claims appended hereto. In this respect, before explaining several embodiments of the technology in detail, it is to be understood that the technology is not limited in its application to the details and construction and to the arrangement of the components set forth in the following description or illustrated in the drawings. The technology is capable of other embodiments and of being practiced and carried out in various ways.

[0023] It is also to be understood that the phraseology and terminology herein are for the purposes of description and should not be regarded as limiting in any respect. Those skilled in the art will appreciate the concepts upon which this disclosure is based and that it may readily be utilized as the basis for designating other structures, methods and systems for carrying out the several purposes of this development. It is important that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present technology.

[0024] These and other aspects of the present system and method will be apparent after consideration of the Detailed Description and Figures herein. It is to be understood, however, that the scope of the technology shall be determined by the claims as issued and not by whether given subject matter addresses any or all issues noted in the Background or includes any features or aspects recited in this Summary.

DRAWINGS

[0025] Non-limiting and non-exhaustive embodiments of the present technology, including the preferred embodiment, are described with reference to the following Figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified.

[0026] Figure 1 depicts a side view of a seal device according to one an embodiment of the present technology.

[0027] Figure 2 is a partial cross sectional view of the seal device of Figure 1 taken along line I-I in a relaxed or uncompressed state in an embodiment of the present technology.

[0028] Figure 3 is a partial cross sectional view of the seal device as it may be compressed between two flanges in an embodiment of the present technology.

[0029] Figure 4 is a partial cross sectional view of another embodiment of the seal device as it may be compressed between two flanges in an embodiment of the present technology.

[0030] Figure 5 is a partial cross sectional view of a further embodiment of the seal device as it may be compressed between two flanges in an embodiment of the present technology

[0031] Figure 6 is a partial cross sectional view of another embodiment of the seal device as it may be compressed between two flanges in an embodiment of the present technology.

[0032] Figure 7 depicts an isometric, cut-away view of a further another embodiment of the seat device of the present technology.

[0033] Figure 8 depicts an isometric, cut-away view of still another embodiment of the seal device of the present technology.

[0034] Figure 9 depicts an isometric, cut-away view of an alternate embodiment of the seal device depicted in Figure 8.

[0035] Figure 10 depicts an isometric, cut-away view of another embodiment of the seal device of the present technology.

[0036] Figure 11 depicts side, cross-sectional, and top cut-away views of another embodiment of a seal member that may be used with the seal device of the present technology.

DETAILED DESCRIPTION

[0037] Embodiments are described more ftilly below with reference to the accompanying

Figures, which form a part hereof and show, by way of illustration, specific exemplary embodiments. These embodiments are disclosed in sufficient detail to enable those skilled in the art to practice the technology. However, embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. The following detailed description is, therefore, not to be taken in a limiting sense.

[0038] The present technology generally concerns seal devices which may be inserted between joint connections in a flow line system. Various embodiments are specifically directed to seal devices which are corrosion resistant and positively affected by hydrodynamic and hydrostatic forces of the fluid contained in a flow line system. It should be appreciated.

however, that the seal device technology described herein could be used for seal device applications other than in flow lines While the exemplary embodiments of the present technology are further described with respect to an annular seal device to be interposed and compressed between flanged-end connections of adjacent pipe sections, it should be understood at the outset of this description that the features and benefits encompassed in the present technology may be applied to seal devices having other configurations, other flow line applications and other joint connections One of ordinary skiil in the art should readily be able to implement the features and benefits described with respect to the present technology in numerous situations requiring the use of seal devices.

[0039] With reference to Figures 1-6, various embodiments of a seal device 100 may include an annular seal member 110, having at least two generally opposite sealing faces 112A and 112B, a radially outer groove 114, and a radially inner channel 120. Thus, in some embodiments of the present technology, the annular seal member 110 is formed to have a generally "H-shaped" cross section. An annular seal retainer 140 may be provided to surround the radially outer portion of the seal member 110 and a portion of the seal retainer 140 extends into the radially outer groove 114 of the seal member 110. In some embodiments, the seal retainer 140 functions to hold the resilient element 130 in place within the recess 132 formed in the seal member 110.

[0040] In some embodiments, the seal device is positioned between two flanges 150, for example, at the juncture between two lengths of pipe. The first and second sealing faces 112A and 112B of the seal member 110 contact and provide a fluid seal between the flanges 150 With reference to Figure 1 , the seal device may further include a central aperture 115 that extends through the center of the seal member 110 and corresponds to a fluid flow line through a section of pipes in particular applications.

[0041] The seal devices of the present technology may be described as including "self- energizing" seals. In one aspect, self-energizing should be construed herein as not requiring the use of a resilient element to work alone or in combination with another structure within the seal device to create a sealing point or zone with one or more adjacent structures. In another aspect,

self-energizing should be construed herein to relate to the shape and size of the seal member(s), whether alone or in comparison with other elements of the seal device. For example, with reference to Figure 2, a seal device 100 is depicted in a partially relaxed state, such as when the seal device 100 is not compressed between two flanges. In this state, various embodiments of the seal device 100 will be provided with a seal retainer 140 having a select seal retainer thickness ti and a seal member 110 having a select seal member thickness t ₂ which is greater than the seal retainer thickness t ₁ when in the relaxed state. With reference to Figure 3 the seal device 100 is depicted as being compressed between two pipe flanges 150. In this state, the seal retainer thickness t ₁ is substantially equal to the seal member thickness t ₂ when interposed and compressed between the joined components of the flow line. Therefore, by virtue of shape and/or size, the seal member 110 provides a self-energizing point or zone of sealing.

[0042] Other aspects of the present technology further provide self-energizing points or zones of sealing by shaping the seal member to react with external forces In various embodiments, the radially inner channel 120 in the seal member 110 is open and exposed to the central aperture 115 of the seal device 100 and, therefore, to the interior of the fluid flow line. In many applications, fluid fills the radially inner channel 120 and exerts a force on the interior walls 122 and 124 of the radially inner channel 120. The area between the side walls 122 of the radially inner channel 120 and the first and second faces 112A and 112B of the seal member 110 form sealing lips 116. The force of the fluid on the side walls 122 forces the lips 116 axially outward thereby creating additional sealing force on the flanges 150 As system pressure increases, the forces on the side walls 122, and the corresponding lips 116, will increase as well to create a tighter seal between the lips 116 and flange surface 150. Therefore, by virtue of the radially inner channel 120 and its configuration, the seal member 110 can react to external forces to provide a self-energizing point or zone of sealing.

[0043] With reference to Figures 4, 5 and 6, some embodiments of the present technology vary the geometry of the radially inner channel 120. In Figure 4, the channel 120 is provided with a "V-shaped" cross section wherein the side walls 122 angle inward to meet a point. In Figure 5, the radially inner channel 120 is provided with a trapezoidal cross section

wherein the side walls 122 are angled inward but terminate at a rear wall 124 Figure 6, depicts another embodiment where the radially inner channel 120 is provided with a parabolic cross section. Further geometries for the radially inner channel 120 are consistent with the intent of this technology as long as they provide force or a component of force in a direction parallel to the central axis of the sealing device 100 to cause a seal between the sealing lips 116 and the flange surfaces 150.

[0044] In one embodiment of the present technology, the seal member 110 is formed from one or more suitable sealing materials, which may vary depending upon the particular sealing application. As an example, these materials include any compressible material suitable for sealing fluids such as: elastomers, metals, resins, and polymers such as polyetheretherketone, perfluorelastomers, and polytetrafluoroethylene (PTFE).

[0045] A protruding section 142 of the seal retainer 140 may be provided to extend into the radially outer groove 114 to create a final restraining surface 144 that may be positioned to contact or be positioned in spaced relationship with the bottom wall 130 of the radially outer groove 114. Various embodiments may provide the radially outer groove 114 with sides that taper so that a width of the radially outer groove 114 is greatest adjacent the outer edge of the seal member 110 and narrowest at the bottom wall 130. This may allow for a friction fit engagement between the radially outer groove 114 and the protruding section 142 as the two are advance toward one another during assembly. In some embodiments, the protruding section 142 may be shaped to have a distal end portion that is at list slightly thicker than a proximal end. Such a shape will accentuate the friction fit character of the design and may promote stability in the joinin of the seal member 110 with the seal retainer 140. Other structural features and topographical shapes of the inner most edge of the seal retainer 140 and the outer edge portion of the seal member 110 are depicted in Figures 7-11 to promote the integrity of the connection between the structures

[0046] Accordingly, the seal member 110 and seal retainer 140 may be sized and adapted to seal a space between joiDed pieces of pipe and allow fluid to flow therethrough without leakage. In various embodiments, the seal member 110 is operative to provide a seal against the

pipe flanges and prevent contact between the fluid and the seal retainer 140. Therefore, in many applications it may not be necessary for the seal retainer 140 to be constructed of a corrosion resistant material when the seal device 100 is used in a highly corrosive environment.

[0047] In some embodiments of the present technology, the seal retainer 140 is formed from a rigid material selected from a group of materials that includes metal and glass-reinforced epoxy, which resist compressive forces. This allows the seal retainer 140 to act as a compression limiter so that regardless of the amount of torque applied to the flange bolts, the force applied to the seal device by the flanges will not over compress and destroy the sealing properties of the seal member 1 10.

[0048] In some embodiments of the present technology, the seal device 100 may be rebuildable. The retainer ring may be made of a rigid material that resists compressive forces. Additionally, it is protected from the process media by the seal member 100. Therefore, after a first use, the seal retainer 140 could be used with a new seal member 110 to create a new seal device 100. In a further embodiment of the present technology, the seal device may be removed and reinstalled in a process flow line, for example, and continue to provide a suitable seal

[0049] Some applications of the seal devices 200 and 300 may produce less than desirable results due to the use and placement of the glass reinforced epoxy layers. For example, portions of the glass reinforced epoxy layers are exposed at the inner diameter of the seal devices 200 and 300 Accordingly, in various applications, the glass reinforced epoxy layers can be engaged by steam and typical process media. Glass reinforced epoxy begins to become unstable at its glass transition temperature. Accordingly, the protective layer may degrade when it is engaged by steam and process media. Such degradation may result in poor isolation performance due to a short across an exposed metal core.

[0050] With reference to Figure 7, a seal device 200 is depicted that may be used in certain applications where the use of glass reinforced epoxy and other such materials may not be desirable. In some embodiments, a pressure energized seal member 210 is positioned at a radially inner edge portion of a seal retainer 240. In some embodiments, the seal member 210 is shaped to have at least two generally opposite sealing faces 212A and 212B, a radially outer

groove 214, and a radially inner channel 220. Thus, in some embodiments of the present technology, the seal member 210 is formed to have a generally "H-shaped" cross section. The seal retainer 240 can be shaped to engage and extend at least partially into the radially outer groove 214 of the seal member 210, as depicted. The thickness of the seal member 210 can be provided to be greater than the thickness of the seal retainer 240 when the seal device 200 is in an uncompressed state. Alternatively, the thickness of the seal member 210 can approximate the thickness of the seal retainer 240 when the seal device 200 is in a compressed state In various embodiments, the radially inner channel 220 in the seal member 210 is open and exposed to a central aperture 215 of the seal device 200 and, therefore, to the interior of the fluid flow line. In many applications, fluid fills the radially inner channel 220 and exerts a force on side interior walls 222 and 224 of the radially inner channel 220 The area between the side walls 222 of the radially inner channel 220 and the first and second faces 212A and 212B of the seal member 210 form sealing lips 216. The force of the fluid on the side walls 222 forces the lips 216 axially outward thereby creating additional sealing force on opposing structures, such as the flanges of pipe sections Increases in system pressure will increase the forces on the side walls 222, and the corresponding lips 216. will increase as well to create a tighter seal between the lips 216 and opposing structures. As described hereinabove with respect to the radially inner channel 120 of sealing device 100, the radially inner channel 220 may be shaped to have various cross-sectional shapes, such as rectangular, triangular, trapezoidal, parabolic, and the like, depending on the intended application. In some embodiments, the seal member 210 is formed from PTFE. In the aforedescribed exemplary embodiment, exposure of the glass reinforced epoxy layers 246 to corrosive environments is eliminated. As such, the corrosion-resistant core 248 is adequately insulated, which remedies the issue of poor isolation performance.

[0051] With reference to Figure 8, a seal device 300 is depicted that replaces the laminated glass reinforced epoxy composite layers 246 of the seal device 200 with layers of high temperature thermoplastic 346, such as polyphenylene sulphide, which is also known as Ryton. The high temperature thermoplastic layers 346 cover a corrosion-resistant core 348 In some embodiments, the corrosion-resistant core 348 may be formed from stainless steel. A pressure energized seal member 310 is provided at a radially inner edge portion of the seal retainer 340

The seal member 310 will, in many embodiments, possess two generally opposite sealing faces 312A and 312B, a radially outer groove 314, and a radially inner channel 320. Accordingly, the seal member 310 may be formed to have a generally "η-shaped" cross section. The seal retainer 310 can be shaped to engage and extend at least partially into the radially outer groove 314 of the seal member 310, as depicted. The thickness of the seal member 310 can be provided to be greater than the thickness of the seal retainer 340 when the seal device 300 is in an uncompressed state. Alternatively, the thickness of the seal member 310 can approximate the thickness of the seal retainer 340 when the seal device 300 is in a compressed state. In various embodiments, the radially inner channel 320 in the seal member 310 is open and exposed to a central aperture 315 of the seal device 300 and, therefore, to the interior of the fluid flow line The radially inner channel 320 may be configured in a manner similar to that described with respect to the radially inner channel 220 of the sealing device 200. Accordingly, the aforedescribed, pressure-energized attributes may be afforded to the seal member 310. Likewise, the radially inner channel 320 may be shaped to have various cross-sectional shapes, such as rectangular, triangular, trapezoidal, parabolic, and the like, depending on the intended application. In some embodiments, the seal member 310 is formed from PTFE. Accordingly, the seal device 300 will prove to be beneficial for use in extreme service applications, such as, high temperature and pressure applications. Moreover, the layers of high temperature thermoplastic 346 can provide the seal device 300 with desirable dielectric properties.

[0052] With reference to Figure 9, a seal device 400 is depicted that incorporates one or more heat and fire-resistant secondary seals 454. A seal retainer 440 provides a support for one or more heat and fire-resistant secondary seals 454. In various embodiments, the secondary seals may be formed to include one or more heat-resistant materials, such as graphite; asbestos; ceramic compounds; or other similar material. The secondary seals 454 may further be formed to include fire-resistant materials, which include various metal and metal alloys. In some embodiments, the fire-resistant material may be graphite and/or stainless steel. In the exemplary embodiment depicted in Figure 9, the secondary seals 454 are provided in the form of C-ring or E-ring type metallic seals, which are positioned in a radially outwardly spaced relationship with the seal member 410. In some embodiments, the seal member 410 is shaped to have at least two

generally opposite sealing faces 412A and 412B, a radially outer groove 414, and a radially inner channel 420. Thus, the seal member 410 may be formed to have a generally "H-shaped" cross section. The seal retainer 440 can be shaped to engage and extend at least partially into the radially outer groove 414 of the seal member 410, as depicted. The thickness of the seal member 410 can be provided to be greater than the thickness of the seal retainer 440 when the seal is in an uncompressed state. Alternatively, the thickness of the seal member 410 can approximate the thickness of the seal retainer 440 when the seal is in a compressed state. The radially inner channel 420 in the seal member 4!0 may be provided such that it is open and exposed to a central aperture 415 of the seal device 400 and, therefore, to the interior of the fluid flow line. The radially inner channel 420 may be configured in a manner similar to that described with respect to the radially inner channel 220 of the sealing device 200. Accordingly, the aforedescribed, pressure-energized attributes may be afforded to the seal member 410. Likewise, the radially inner channel 420 may be shaped to have various cross-sectional shapes, such as rectangular, triangular, trapezoidal, parabolic, and the like, depending on the intended application. In some embodiments, the seal member 610 is formed from PTFE.

[0053] Referring to Figure 10, a seal device 500 is depicted that, in certain embodiments may be characterized as a non-critical service seal, which may also be used for electrical flange isolation and/or general sealing applications. The seal device is generally provided with a with a glass reinforced epoxy seal retainer 540. A pressure energized seal member 510 is positioned at a radially inner edge portion of a seal retainer 540 The seal member 510 may include at least two generally opposite sealing faces 512A and 512B, a radially outer groove 514, and a radially inner channel 520 Such an arrangement will provide the seal member 510 with a generally "H- shaped" cross section. The seal retainer 540 can be shaped to engage and extend at least partially into the radially outer groove 514 of the seal member 510. The thickness of the seal member 510 can be greater than the thickness of the seal retainer 540 when the seal is in an uncompressed state. Alternatively, the thickness of the seal member 510 can be equal to the thickness of the seal retainer 540 when the seal is in a compressed state. In various embodiments, the radially inner channel 520 in the seal member 510 is open and exposed to a central aperture 515 of the seal device 500 and, therefore, to the interior of the fluid flow line. The radially inner channel

520 may be configured in a manner similar to that described with respect to the radially inner channel 220 of the sealing device 200. Accordingly, the aforedescribed, pressure-energized attributes may be afforded to the seal member 510. Likewise, the radially inner channel 520 may be shaped to have various cross-sectional shapes, such as rectangular, triangular, trapezoidal, parabolic, and the like, depending on the intended application. In some embodiments, the seal member 510 is formed from PTFE. In various embodiments, the seal device 500 is provided also provided with secondary seals 554 (not depicted). In some embodiments, the secondary seals 554 are provided as either spring-energized face seals or elastomeric o-ring seals. The combination of the seal member 510 and the secondary seals 554 provided improved chemical resistance and dielectric properties, to the seal device 500.

[0054] With reference to Figure 11 , a seal device 600 is depicted that is provided with a seal member 610 having at least two separate sealing zones. The seal device is generally provided with a with a seal retainer 640, which may be provided in the configurations and material combinations as described with respect to seal retainers 110, 210, 310, 410, 510 and 610. A seal member 610 is positioned at a radially inner edge portion of the seal retainer 640. The seal member 610 may include at least two generally opposite sealing faces 612A and 612B, a radially outer groove 614. and a radially inner channel 620. Such an arrangement will provide the seal member 610 with a generally "H-shaped" cross section. The seal retainer 640 can be shaped to engage and extend at least partially into the radially outer groove 614 of the seal member 610 A first sealing zone may be profided as described previously with respect to other embodiments. In one aspect, the thickness of the seal member 610 can be greater than the thickness of the seal retainer 640 when the seal is in an uncompressed state. Alternatively, the thickness of the seal member 610 can be equal to the thickness of the seal retainer 640 when the seal is in a compressed state. ID other aspects, the radially inner channel 620 in the seal member 610 is open and exposed to a central aperture 615 of the seal device 600 and, therefore, to the interior of the fluid flow line. The radially inner channel 620 may be configured in a manner similar to that described with respect to the radially inner channel 220 of the sealing device 200. Accordingly, the aforedescribed, self-energized attributes may be afforded to the seal member 610. Likewise, the radially inner channel 620 may be shaped to have various cross-sectional

shapes, such as rectangular, triangular, trapezoidal, parabolic, and the like, depending on the intended application As described previously, the sealing points or zones afforded by the first sealing zone are self-energizing.

[0055] In some embodiments, the seal member 610 may provide a second sealing zone near a radially outer edge portion of the seal member 610. In some embodiments, the second sealing zone may be provided by self-energizing seal characteristics, as described previously However, the second sealing zone may also be provided through the use of spring-energized features. In particular, the seal member 640 may be provided with a pair of J-shaped cuts 656, which form a pair of radial face seals 658. In a second sealing zone, the seal member 640 is provided with a pair of J-shaped cuts 656, which form a pair of radial face seals 658. In such an embodiment, coil springs 660 may be disposed within the J-shaped grooves 656 to provide positive spring energy to the face seals 658 and enhance the sealing engagement between the radial face seals 658 and the sealing surfaces of adjacent structures, such as the flange faces of pipe sections. Where the particular seal device configuration permits, the face seals 658 can also be energized by system pressure As with (lie aforedescribed seal members, 210, 310. 410, and 510. the seal member 610 may be formed from compressible materials suitable for sealing fluids such as. elastomers, metals, resins, and polymers such as polyetheretherketone, perfluorelastomers, and polytetrafluoroethylene.

[0056] Although the technology has been described in language that is specific to certain structures, materials, and methodological steps, it is to be understood that the technology defined in the appended claims is not necessarily limited to the specific structures, materials, and/or steps described. Rather, the specific aspects and steps are described as forms of implementing the claimed technology. Since many embodiments of the technology can be practiced without departing from the spirit and scope of the technology, the technology resides in the claims hereinafter appended. Unless otherwise indicated, all numbers or expressions, such as those expressing dimensions, physical characteristics, etc. used in the specification (other than the claims) are understood as modified in all instances by the term "approximately." At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the claims.

each numerical parameter recited in the specification or claims which is modified by the term "approximately'' should at least be construed in light of the number of recited significant digits and by applying ordinary rounding techniques. Moreover, all ranges disclosed herein are to be understood to encompass and provide support for claims that recite any and all subranges or any and all individual values subsumed therein. For example, a stated range of 1 to 10 should be considered to include and provide support for claims that recite any and all subranges or individual values that are between and/or inclusive of the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more and ending with a maximum value of 10 or less (e.g.. 5.5 to 10, 2.34 to 3.56, and so forth) or any values from 1 to 10 (e.g., 3, 5.8, 9.9994, and so forth).