PRIORITY

[0001] This application claims priority to German Patent App. No. 10_2013_007_528.9, entitled "Valve, in particular plug valve," filed May 3, 2013, the disclosure of which is incorporated by reference herein.

BACKGROUND

[0002] The present disclosure relates to devices for regulating flow of a fluid through a passage formed in a valve, either by closing the passage or by restricting the passage by a definite predetermined motion of a flow-restricting-element, and more particularly to a plug valve wherein the valve stem is associated with means to seal it to prevent leakage of fluid between the inside and outside of the valve body. Furthermore, the present disclosure relates to devices and methods for limiting leakage of fluid between the inside and outside of the valve body when the plug valve is exposed to certain thermal conditions. Among other examples, organizations, and/or standards, examples of such thermal conditions are described by the American Petroleum Institute ("API") and the International Organization for Standardization ("ISO") in Standard API 607 ("Fire Test for Soft-Seated Quarter Turn Valves"), Standard API 598 ("Valve Inspection and Testing"), Standard API 6FA ("Specification for Fire Test for Valves"), and ISO Standard 10497 ("Testing of Valves: Fire Type-Testing Requirements").

[0003] Plug valves are mechanical devices that may be utilized to regulate the flow of fluids such as liquids, gases, and slurries over a wide range of temperatures and pressures. These valves are used in a variety of applications, particularly industrial applications (e.g. refining, chemical, petrochemical, mining, pharmaceutical, etc.). Plug valves may be operated manually by hand or operated mechanically with pneumatic, hydraulic, or electric actuators.

[0004] Valves may be exposed to wide and rapid temperature changes, i.e. thermal cycling, causing its seals to contract and expand rapidly, which may degrade the seals over time and impact the reliability of the valve. In addition, the reliability of valve seals may be impacted by vibrations and rotational forces. For example, during operations, a stem seal is often exposed to rotational forces as a valve is moved between its open and closed position, which can degrade the integrity of the stem seal. Additionally, valves are often exposed to high pressure operating conditions and pressure drops, which cause vibrations, that may degrade the seals. Once the seals begin to degrade, fluid often begins to leak from the inside to the outside of the valve. The valve must typically be removed from service for repair in order to prevent further leakage, which can lead to costly process downtime and maintenance. One available option to prevent further leakage in a traditional sleeved plug valve is to further tighten the adjustment bolts. However, this option requires intervention from operations personnel. Moreover, the additional force required to tighten the adjustment bolts can damage the valve and its components, and can significantly increase the valve operating torque.

[0005] Accordingly, it may be desirable to provide a more robust plug valve having a sealing assembly capable of preventing leakage under demanding environmental and operating conditions while also improving the reliability of the valve seals and reducing maintenance needs. The valve is to meet the global standards in terms of the primary seal and/or the secondary seals to the surroundings, wherein, in particular, the global standards relating to fire resistance are also to be met.

[0006] While several valves and fluid systems have been made and used, it is believed that no one prior to the inventors has made or used the invention described in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] While the specification concludes with claims which particularly point out and distinctly claim this technology, it is believed this technology will be better understood from the following description of certain examples taken in conjunction with the accompanying drawings, in which like reference numerals identify the same elements and in which:

[0008] FIG. 1 depicts a cross-sectional side view of an exemplary valve, designed as a plug valve;

[0009] FIG. 2 depicts a perspective view of the valve of FIG. 1 ;

[00010] FIG. 3 depicts an exploded perspective view of an axial spring element, a radial spring element, and of a diaphragm of the valve of FIG. 1 ;

[00011] FIG. 4 depicts a partial cross-sectional side view of a plug with the spring elements and the diaphragm of FIG. 3;

[00012] FIG. 5 depicts a partially exploded perspective view of the valve of FIG. 1 ;

[00013] FIG. 6 depicts a partial cross-sectional side view of the valve of FIG. 1 ;

[00014] FIG. 7 depicts a top view of the valve of FIG. 1 ;

[00015] FIG. 8 depicts a cross-sectional side view of the valve of FIG. 1, with a sleeve and the diaphragm having been destroyed and with the plug of FIG. 4 having been driven internally downwardly such as to seal the plug against a pair of sealing rings formed in an interior surface of the valve;

[00016] FIG. 9 depicts a perspective view of the valve of FIG. 1 in the condition described in FIG. 8;

[00017] FIG. 10 depicts a cross-sectional side view of an exemplary alternative valve, designed as a plug valve;

[00018] FIG. 11 depicts a perspective view of the valve of FIG. 10;

[00019] FIG. 12 depicts a cross-sectional side view of the valve of FIG. 10, with a sleeve and a diaphragm having been destroyed and with a plug of the valve having been driven internally downwardly such as to seal the plug against a pair of sealing rings formed in an interior surface of the valve; [00020] FIG. 13 depicts a perspective view of the valve of FIG. 10 in the condition described in FIG. 12;

[00021] FIG. 14 depicts a perspective view of another exemplary alternative valve, designed as a plug valve;

[00022] FIG. 15 depicts a cross-sectional side view of the valve of FIG. 14;

[00023] FIG. 16 depicts a detailed cross-sectional side view of the valve of FIG. 14;

[00024] FIG. 17 depicts an exploded perspective view of an upper assembly of the valve of FIG. 14;

[00025] FIG. 18 depicts a perspective view of a cover of the upper assembly of FIG. 17;

[00026] FIG. 19 depicts a cross-sectional side view of the cover of FIG. 18;

[00027] FIG. 20 depicts another perspective view of the cover of FIG. 18;

[00028] FIG. 21 depicts a perspective view of a gland follower of the upper assembly of FIG. 17;

[00029] FIG. 22 depicts a cross-sectional side view of the gland follower of FIG. 21 ;

[00030] FIG. 23 depicts an exploded perspective view of sealing elements of the upper assembly of FIG. 17;

[00031] FIG. 24 depicts a perspective view of a resilient diaphragm of the sealing elements of FIG. 23;

[00032] FIG. 25 depicts a cross-sectional side view of the resilient diaphragm of FIG. 24;

[00033] FIG. 26 depicts a perspective view of a resilient disc member of the sealing elements of FIG. 23;

[00034] FIG. 27 depicts a cross-sectional side view of the resilient disc member of FIG.

26; [00035] FIG. 28 depicts a cross-sectional side view of a plug of the valve of FIG. 14 with the resilient diaphragm of FIG. 24, the resilient disc member of FIG. 26, and spring elements of the upper assembly of FIG. 17;

[00036] FIG. 29 depicts a top view of the valve of FIG. 14;

[00037] FIG. 30 depicts a cross-sectional side view of the valve of FIG. 14, with a sleeve and the resilient diaphragm of FIG. 24 having been destroyed and with the plug of FIG. 28 having been driven internally downwardly such as to seal the plug against a pair of sealing rings formed in an interior surface of the valve;

[00038] FIG. 31 depicts a perspective view of yet another exemplary alternative valve, designed as a plug valve;

[00039] FIG. 32 depicts a cross-sectional side view of the valve of FIG. 31 ;

[00040] FIG. 33 depicts a detailed cross-sectional side view of the valve of FIG. 31 ;

[00041] FIG. 34 depicts an exploded perspective view of an upper assembly of the valve of FIG. 31 ;

[00042] FIG. 35 depicts a perspective view of a cover of the upper assembly of FIG. 34;

[00043] FIG. 36 depicts a cross-sectional side view of the cover of FIG. 35;

[00044] FIG. 37 depicts a perspective view of a compression ring of the upper assembly of FIG. 34;

[00045] FIG. 38 depicts a cross-sectional side view of the compression spring of FIG. 37;

[00046] FIG. 39 depicts an exploded perspective view of sealing elements of the upper assembly of FIG. 34;

[00047] FIG. 40 depicts a cross-sectional side view of a plug of the valve of FIG. 31 with a resilient diaphragm, a resilient disc member, and spring elements of the upper assembly of FIG. 34;

[00048] FIG. 41 depicts a top view of the valve of FIG. 31 ; [00049] FIG. 42 depicts a cross-sectional side view of the valve of FIG. 31 , with a sleeve and the resilient diaphragm of FIG. 40 having been destroyed and with the plug of FIG. 40 having been driven internally downwardly such as to seal the plug against a pair of sealing rings formed in an interior surface of the valve;

[00050] FIG. 43 depicts a perspective view of yet another exemplary alternative valve, designed as a plug valve;

[00051] FIG. 44 depicts a cross-sectional side view of the valve of FIG. 43;

[00052] FIG. 45 depicts a detailed cross-sectional side view of the valve of FIG. 43;

[00053] FIG. 46 depicts an exploded perspective view of an upper assembly of the valve of FIG. 43;

[00054] FIG. 47 depicts a perspective view of a cover of the upper assembly of FIG. 46;

[00055] FIG. 48 depicts a cross-sectional side view of the cover of FIG. 47;

[00056] FIG. 49 depicts an exploded perspective view of sealing elements of the upper assembly of FIG. 46;

[00057] FIG. 50 depicts a perspective view of an O-ring of the sealing elements of FIG.

49;

[00058] FIG. 51 depicts a perspective view of a metallic element of the sealing elements of FIG. 49;

[00059] FIG. 52 depicts a cross-sectional side view of a plug of the valve of FIG. 43 with a resilient diaphragm, a resilient disc member, and spring elements of the upper assembly of FIG. 46;

[00060] FIG. 53 depicts a top view of the valve of FIG. 43;

[00061] FIG. 54 depicts a cross-sectional side view of the valve of FIG. 43, with a sleeve and the resilient diaphragm of FIG. 52 having been destroyed and with the plug of FIG. 52 having been driven internally downwardly such as to seal the plug against a pair of sealing rings formed in an interior surface of the valve; [00062] FIG. 55 depicts a perspective view of yet another exemplary alternative valve, designed as a plug valve;

[00063] FIG. 56 depicts a cross-sectional side view of the valve of FIG. 55;

[00064] FIG. 57 depicts a detailed cross-sectional side view of the valve of FIG. 55;

[00065] FIG. 58 depicts an exploded perspective view of an upper assembly of the valve of FIG. 55;

[00066] FIG. 59 depicts a perspective view of a cover of the upper assembly of FIG. 58;

[00067] FIG. 60 depicts a cross-sectional side view of the cover of FIG. 59;

[00068] FIG. 61 depicts another cross-sectional side view of the cover of FIG. 59;

[00069] FIG. 62 depicts a perspective view of a compression ring of the upper assembly of FIG. 58;

[00070] FIG. 63 depicts a cross-sectional side view of the compression ring of FIG. 62;

[00071] FIG. 64 depicts an exploded perspective view of sealing elements of the upper assembly of FIG. 58;

[00072] FIG. 65 depicts a cross-sectional side view of a plug of the valve of FIG. 55 with a resilient diaphragm, a resilient disc member, and the compression ring of FIG. 62;

[00073] FIG. 66 depicts a top view of the valve of FIG. 55;

[00074] FIG. 67 depicts a perspective view of yet another exemplary alternative valve, designed as a plug valve;

[00075] FIG. 68 depicts a cross-sectional side view of the valve of FIG. 67;

[00076] FIG. 69 depicts a detailed cross-sectional side view of the valve of FIG. 67;

[00077] FIG. 70 depicts an exploded perspective view of an upper assembly of the valve of FIG. 67;

[00078] FIG. 71 depicts a perspective view of a cover of the upper assembly of FIG. 70; [00079] FIG. 72 depicts a top view of the cover of FIG. 71 ;

[00080] FIG. 73 depicts a cross-sectional side view of the cover of FIG. 71 ;

[00081] FIG. 74 depicts another cross-sectional side view of the cover of FIG. 71 ;

[00082] FIG. 75 depicts a perspective view of a compression ring of the upper assembly of FIG. 70;

[00083] FIG. 76 depicts a cross-sectional side view of the compression ring of FIG. 75;

[00084] FIG. 77 depicts a perspective view of a gland follower of the upper assembly of FIG. 70;

[00085] FIG. 78 depicts a cross-sectional side view of the gland follower of FIG. 75;

[00086] FIG. 79 depicts an exploded perspective view of sealing elements of the upper assembly of FIG. 70;

[00087] FIG. 80 depicts a cross-sectional side view of a plug of the valve of FIG. 67 with a resilient diaphragm, a resilient disc member, and the compression ring of FIG. 75; and

[00088] FIG. 81 depicts a top view of the valve of FIG. 67.

[00089] The drawings are not intended to be limiting in any way, and it is contemplated that various embodiments of the technology may be carried out in a variety of other ways, including those not necessarily depicted in the drawings. The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present technology, and together with the description serve to explain the principles of the technology; it being understood, however, that this technology is not limited to the precise arrangements shown.

DETAILED DESCRIPTION

[00090] The following description of certain examples of the technology should not be used to limit its scope. Other examples, features, aspects, embodiments, and advantages of the technology will become apparent to those skilled in the art from the following description, which is by way of illustration, one of the best modes contemplated for carrying out the technology. As will be realized, the technology described herein is capable of other different and obvious aspects, all without departing from the technology. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not restrictive.

[00091] It is further understood that any one or more of the teachings, expressions, embodiments, examples, etc. described herein may be combined with any one or more of the other teachings, expressions, embodiments, examples, etc. that are described herein. The following-described teachings, expressions, embodiments, examples, etc. should therefore not be viewed in isolation relative to each other. Various suitable ways in which the teachings herein may be combined will be readily apparent to those of ordinary skill in the art in view of the teachings herein. Such modifications and variations are intended to be included within the scope of the claims.

[00092] I. Exemplary Plug Valve

[00093] FIGS. 1-9 illustrate an exemplary valve (1). At least part of the valve (1) may be constructed and operable in accordance with at least some of the teachings of European Patent ("EP") 1 155250 Bl, entitled "Fitting," and published May 14, 2003; EP 0100629 Bl, entitled "Plug Valve," and published January 21, 1987; EP 0087824 Bl, entitled "Plug Valve," and published February 19, 1986; and EP 0032038 Bl, entitled "Improved Rotary Plug Valve," and published May 28, 1984. The disclosures of each of the foregoing patents, publications, and applications are incorporated by reference herein. As described therein and as will be described in greater detail below, the valve (1) is operable to regulate the flow of a fluid through a passage (12) formed in the valve (1), either by closing the passage (12) or by restricting it by a definite predetermined motion of a flow-restricting-element, i.e., a plug (4). It should also be understood that the valve (1) may have various structural and functional similarities with the XOMOX® Sleeved Plug Valves, the XOMOX® Multi-Port Sleeved Plug Valves, the XOMOX® Jacketed Sleeved Plug Valves, the XOMOX® High Pressure Sleeved Plug Valves, the XOMOX® Full Port Sleeved Plug Valves, the XOMOX® HF Sleeved Plug Valves, the XOMOX® Cage Control Sleeved Plug Valves, the XOMOX® Easi-Sleeve Sleeved Plug Valves, and/or the XOMOX® Severe Service Valves. Furthermore, the valve (1) may have various structural and functional similarities with the devices taught in any of the other references that are cited and incorporated by reference herein.

[00094] A. Exemplary Lower Assembly

[00095] As shown in FIGS. 1 and 2, the valve (1) is designed as a plug valve. A lower assembly of the valve (1) of the present example comprises a valve body (2), a sleeve (18), a plug (4), a resilient disc member (40), and a resilient diaphragm (42). The valve body (2) includes the passage (12) that passes through the valve body (2) from a first end (1 A) of the valve body (2) to a second end (IB) of the valve body (2) along a longitudinal axis (LAI). (Although the valve (1) of the present example is described as having the first end (1A) and the second end (IB), it should be appreciated that valve (1) may comprise any appropriate number of ends. For instance, among other examples, the valve

(1) may be designed as a "three-way" valve further comprising a third end.) The valve body (2) further includes an interior chamber (3) that extends internally from a top surface of the valve body (2) along a vertical axis (VA1) within the valve body (2). As best seen in FIG. 2, the passage (12) intersects and passes through the interior chamber (3) thereby forming a pair of openings (13, 15) where the passage (12) intersects the interior chamber (3). As will be discussed in more detail below, the interior chamber (3) includes a tapered interior surface associated with a sleeve (18) to thereby provide a fluid seal about the openings (13, 15). Also, as will be discussed in more detail below, the plug (4) is rotatably disposed within the interior chamber (3) such that the plug (4) is free to rotate within the interior chamber (3) about the vertical axis (VA1) to thereby selectively open, close, or restrict the flow of fluid through the passage (12).

[00096] The valve body (2) includes a first flange (7) disposed at the first end (1 A) of the valve body (2) and a second flange (9) disposed at the second end (IB) of the valve body

(2) . An inlet opening (8) is formed in the first flange (7) and provides access to the passage (12) formed in the valve body (2). An outlet opening (10) is formed in the second flange (9) and provides access to the passage (12) formed in the valve body (2). It should be understood that the flanges (7, 9) of the present example may comprise any appropriate type or combination of flanges, including but not limited to a Raised Face ("RF") flange, a Flat Face Flange ("FF"), a Screwed End Connection ("SE"), a Butt Weld End Connection ("BW"), and/or a Socket Weld End Connection ("SW").

[00097] The valve (1) further includes a sleeve (18) disposed within the interior chamber (3). The sleeve (18) is pressed into the interior chamber (3) of the valve body (2) to thereby create an interference or friction fit between the sleeve (18) and the interior chamber (3) so as to inhibit movement of the sleeve (18) within the interior chamber (3). As will be discussed in more detail below, the sleeve (18) is configured to rotatably receive the plug (4) such that the plug (4) is operable to rotate within and relative to the sleeve (18) about the vertical axis (VA1). The sleeve (18) of the present example comprises plastic, in particular polytetrafluoroethylene ("PTFE"), but may comprise any other suitable material. The sleeve (18) defines a hollow conical-shaped interior, tapering downwardly from a larger diameter to a smaller diameter. An interior surface (19) of the sleeve (18) is tapered such that the interior surface (19) is defined by an angle (Θ1) relative to vertical axis (VA1). The angle (91) of the present example is in the range between 4° and 6°, preferably in the range between 4.5° and 5.5°, and, in particular, essentially at 5°. An exterior surface (16) of the plug (4) is similarly tapered such that the exterior surface (16) is also defined by the angle (Θ1) relative to vertical axis (VA1). Such an angle may allow for a reduction in the torque required to rotate the plug (4) within the sleeve (18) as compared to plugs having an angle (Θ1) of 2° for example.

[00098] The sleeve (18) includes a pair of openings (23, 25) formed in a sidewall of the sleeve (18). (It should be appreciated that in those versions of the valve (1) having more than the first end (1A) and the second end (IB), the sleeve (18) may comprise more than the pair of openings (23, 25).) The interior chamber (3) of the valve body (2) comprises a pair of sealing rings (20, 22) extending radially inwardly from the interior surface of the interior chamber (3) adjacent to the openings (13, 15) of passage (12). The sleeve (18) is pressed into the interior chamber (3) of the valve body (2), such that the openings (23, 25) of the sleeve (18) are substantially aligned with the openings (13, 15) of passage (12) within the valve body (2), and such that the sealing rings (20, 22) are disposed within the openings (23, 25) of the sleeve (18) to thereby inhibit movement of the sleeve (18) within the interior chamber (3). [00099] As discussed above, the exterior surface (16) of the plug (4) is tapered in a manner similar to the sleeve (18) discussed above such that the exterior surface (16) of the plug (4) is defined by the angle (Θ1) relative to the vertical axis (VAl). Also as discussed above, the sleeve (18) is configured to rotatably receive the plug (4) such that the plug (4) is operable to rotate within and relative to the sleeve (18) about the vertical axis (VAl). The plug (4) is thus held floatingly within the hollow interior of the sleeve

(18) by engagement with the interior surface (19) of the sleeve (18). It should be understood that, because the exterior surface (16) of the plug (4) and the interior surface

(19) of the sleeve (18) comprise tapered surfaces defined by the similar angle (Θ1), the exterior surface (16) of the plug (4) will contact the interior surface (19) of the sleeve (18) across substantially an entire height (HI) of the sleeve (18) to thereby provide a fluid seal between the interior surface (19) of the sleeve (18) and the exterior surface (16) of the plug (4) such that, when the valve (1) is assembled, fluid may not pass between the plug (4) and the sleeve (18). It should be understood that as the plug (4) is driven downwardly into the sleeve (18), the tapered exterior surface (16) of the plug (4) will exert an outwardly directed force upon the sleeve (18). Such outward force will cause an exterior surface (21) of the sleeve (18) to bear against an interior surface of the interior chamber (3) to thereby provide a fluid seal between the interior surface of the interior chamber (3) and the sleeve (18). Such outward force will further cause the sleeve (18) to expand into the spaces within the interior chamber (3) of the valve body (2) adjacent to the sealing rings (20, 22) to thereby increase the engagement between the sleeve (18) and the sealing rings (20, 22) so as to further inhibit movement of the sleeve (18) within the interior chamber (3). As will be discussed in more detail below, the plug (4) may be driven further downward relative to the sleeve (18) to thereby adjust the fluid seal between the plug (4) and the sleeve (18) and/or the fluid seal between the sleeve (18) and the interior surface of the interior chamber (3).

[000100] The plug (4) comprises a passage (14) that passes completely through the plug (4). From the discussion above, it will be appreciated that the plug (4) is rotatable about the vertical axis (VAl) to thereby selectively open, close, or partially restrict the flow of fluid through the passage (12). In particular, the plug (4) is rotatable within the sleeve (18) between an open position and a closed position. The passage (14) of the plug (4) is configured to substantially align with the passage (12) of the valve body (2) when the plug (4) is in the open position to thereby provide for the flow of fluid through the passage (12) of the valve body (2). As shown in FIG. 1, with the plug (4) in the closed position, the passage (14) of the plug (4) is essentially orthogonal to the passage (12) of the valve body (2) such that the plug (4) blocks the flow of fluid through the passage (12) of the valve body (2) via the fluid seal formed between the plug (4) and the sleeve (18). It should be understood that, the plug (4) may be rotated manually via a lever or wheel among other mechanisms, and may additionally or alternatively be rotated mechanically via a pneumatic, hydraulic, or electric actuator among other devices. It should further be understood that the passage (14) of the plug (4) may comprise any shape and/or size, and need not necessarily match a shape of the passage (12) of the valve body (2). For instance, the passage (14) of the plug (4) may comprise a rectangular shape among any other appropriate shape. (It should be appreciated that in those versions of the valve (1) having more than the first end (1A) and the second end (IB), the plug (4) may be rotated within the sleeve (18) so as to partially and/or completely align and/or block one or more passages within the valve (1).)

[000101] A valve stem (28) extends upwardly from a top surface (44) of the plug (4) and is coupled, preferably integrally, thereto. The valve stem (28) extends vertically through a vertical through bore (39) of a retaining member (30) to an external space (31). The valve stem (28) is configured to provide a means by which a user may manually or mechanically rotate the plug (4) within the sleeve (18) about the vertical axis (VA1). For instance, a lever or wheel may be coupled with an exposed portion (29) of the valve stem (28) to thereby allow a user to manually rotate the plug (4). Additionally or alternatively, a pneumatic, hydraulic, or electric actuator may be mechanically coupled with the exposed portion (29) of the valve stem (28) to thereby allow a user to mechanically rotate the plug (4).

[000102] The interior chamber (3) of the valve body (2) presents a first circular lip (41), a second circular lip (63), a third circular lip (71), and a plurality of arcuate projections (66) extending inwardly from the interior surface of the interior chamber (3). A top surface of the circular lip (41) presents a channel (43). The channel (43) of the present example comprises a rectangular profile but may comprise any appropriate profile. With the plug (4) disposed within the sleeve (18), the top surface of the circular lip (41) is substantially horizontally aligned with the top surface (44) of the plug (4). A resilient circular diaphragm (42) is disposed within the interior chamber (3) and rests upon the top surface (44) of the plug (4) and the top surface of the circular lip (41). As best seen in FIG. 4, the top surface (44) of plug (4) comprises a pair of circular projections (49). The circular projections (49) of the present example comprise trapezoidal profiles but may comprise any appropriately shaped profile. The circular projections (49) are configured to engage the diaphragm (42) to thereby inhibit inadvertent displacement of the diaphragm (42). As will be discussed in more detail below, inadvertent displacement of the diaphragm (42) is further inhibited by components of an upper assembly of the valve (1). The diaphragm (42) comprises an essentially cylindrical projection (46) extending from a center of the top surface of the diaphragm (42). The cylindrical projection (46) comprises a circular through bore (51) extending completely through the cylindrical projection (46) such that the valve stem (28) may be slidably and rotatably disposed within the cylindrical projection (46). As will be discussed in more detail below, an interior surface (48) of the cylindrical projection (46) is configured to bear against an exterior surface (55) of the valve stem (28) so as to provide a fluid seal between the cylindrical projection (46) of the diaphragm (42) and the valve stem (28). The diaphragm (42) of the present example may comprise PTFE, rubber, stainless steel, or any other appropriate material. It should be appreciated that, a retaining member (not shown) may be provided to substantially completely encompass the cylindrical projection (46) to thereby inhibit extrusion and/or excessive deformation of the diaphragm (42), in particular the cylindrical projection (46). ] The resilient disc member (40) of the lower assembly is configured to provide a fluid seal between the cylindrical projection (46) of the diaphragm (42) and the valve stem (28). The disc member (40) comprises a plurality of radially inwardly biased resilient tabs (50) radially disposed about an interior portion of the disc member (40). The resilient tabs (50) are designed as individual tabs that are separated from each other by means of a plurality of slots (52). As best seen in FIG. 4, a top portion of the cylindrical projection (46) presents a radially outwardly extending projection (56). The projection (56) is configured to selectively couple the disc member (40) to the diaphragm (42) via engagement with the resilient tabs (50) of the disc member (40). Proper coupling of the disc member (40) and the diaphragm (42) ensures the reliability of the fluid seal between the cylindrical projection (46) of the diaphragm (42) and the valve stem (28) particularly during axial and/or radial movement of the plug (4).

[000104] As discussed above, when assembled, the valve stem (28) of the plug (4) is slidably and rotatably disposed within the cylindrical projection (46) of the diaphragm (42). When coupled with the diaphragm (42), the resilient tabs (50) of the disc member (40) are configured to bear against an exterior surface (57) of the cylindrical projection (46) of the diaphragm (42) to thereby drive the cylindrical projection (46) radially inwardly against the exterior surface (55) of the valve stem (28). In particular, as indicated by an arrow (60) in FIG. 4, an inwardly directed radial force is exerted on the exterior surface (55) of the valve stem (28) by the resilient tabs (50) via the interior surface (48) of the cylindrical projection (46) of the diaphragm (42). This engagement between the interior surface (48) of the cylindrical projection (46) and the exterior surface (55) of the valve stem (28) is configured to provide a fluid seal between the cylindrical projection (46) of the diaphragm (42) and the valve stem (28).

[000105] The disc member (40) and resilient tabs (50) may comprise any appropriate resilient material, including, but not limited to spring steel. Although a one-piece design of the disc member (40) and the resilient tabs (50) has been shown, the cylindrical projection (46) of the diaphragm (42) can be pressed against the valve stem (28) by any appropriate method. For instance, a tension spring and/or an annular spring, among other devices/methods, may be used to drive the cylindrical projection (46) radially inwardly against the exterior surface (55) of the valve stem (28) in lieu of the resilient tabs (50).

[000106] B. Exemplary Dynamic Upper Assembly

[000107] The upper assembly of the valve (1) of the present example comprises a plurality of resilient members (38) and a plurality of retaining components including a retaining member (30), a locking ring (34), an atmosphere collar (74), and a sealing element (92). As will be discussed in more detail below, the retaining member (30) is selectively secured to the valve body (2) within the interior chamber (3) by means of the atmosphere collar (74) and the locking ring (34). As mentioned above, and as best seen in FIG. 1 , the retaining member (30) includes a central through bore (39) such that the retaining member (30) may be slid over the valve stem (28). The retaining member (30) further includes a cylindrical protrusion (33) having a cylindrical recess (36) formed therein. With the retaining member (30) secured within the interior chamber (3) of the valve body (2), a bottom surface of the cylindrical protrusion (33) is configured to bear against a top surface of the diaphragm (42) to thereby compress the diaphragm (42) between the bottom surface of the cylindrical protrusion (33) and the top surface of the circular lip

(41) of the interior chamber (3). Such compression is configured to inhibit inadvertent displacement of the diaphragm (42). Such compression may further cause the diaphragm

(42) to flow into the channel (43) formed in the top surface of the circular lip (41) to thereby further inhibit inadvertent displacement of the diaphragm (42). Thus, it should be appreciated that channel (43) is configured to inhibit inadvertent displacement of the diaphragm (42). In some embodiments of the retaining member (30), the bottom surface of the cylindrical protrusion (33) may comprise features (e.g., a channel, a projection, etc.) configured to engage the top surface of the diaphragm (42) to thereby further inhibit inadvertent displacement of the diaphragm (42) in addition to or in lieu of the channel

(43) formed in the top surface of the circular lip (41). 8] As best seen in FIG. 1, the cylindrical recess (36) of the retaining member (30) comprises an open end (37). With the retaining member (30) secured within the interior chamber (3) of the valve body (2), the open end (37) of the cylindrical recess (36) opens downwardly such that it opens toward the interior chamber (3) of the valve body (2). The cylindrical recess (36) is configured to receive the plurality of resilient members (38). A cylindrical protrusion (77) extends from a top surface (79) of the cylindrical recess (36) and defines a gap between a sidewall of the cylindrical recess (36) and the cylindrical protrusion (77). An upper portion of the resilient members (38) is configured to be positioned within this gap so as to inhibit inadvertent displacement of the resilient members (38). The resilient members (38) may comprise a plurality of Belleville washers, a single spring, a plurality of springs, or any other appropriate resilient biasing element or elements. When assembled, the resilient members (38) are configured to axially impinge upon and/or preload the plug (4) within the sleeve (18) to thereby drive the plug (4) downwardly within the sleeve (18) relative to and along the vertical axis (VAl). In particular, the resilient members (38) are configured to bear axially upwardly against the top surface (79) of the cylindrical recess (36) and axially downwardly against the top surface (44) of the plug (4) via the disc member (40) and the diaphragm (42). As best seen in FIG. 4, and as indicated by an arrow (58), this downwardly directed axial force is exerted upon the top surface (44) of the plug (4) by the resilient members (38) via the disc member (40) and the diaphragm (42) so as to compress the diaphragm (42) between the disc member (40) and the top surface (44) of the plug (4). It should therefore be understood that because the resilient members (38) cause the bottom surface of the diaphragm (42) to bear against the top surface (44) of the plug (4), a fluid seal will be provided there between. Furthermore, it should be appreciated from the discussion above, that this downwardly directed axial force exerted upon the plug (4) by the resilient members (38) is configured to drive the plug (4) downwardly into the sleeve (18) to further provide for the fluid seal between the exterior surface (16) of the plug (4) and the interior surface (19) of the sleeve (18) and/or the fluid seal between the exterior surface (21) of the sleeve (18) and the interior surface of the interior chamber (3). 9] The locking ring (34) of the upper assembly is configured to secure the retaining member (30) within the interior chamber (3) of the valve body (2). As best seen in FIG. 1, the locking ring (34) includes a central through bore (81) such that the retaining member (30) may be slid over the valve stem (28) and an upper cylindrical portion (53) of the retaining member (30). As best seen in FIG. 5, the locking ring (34) comprises a plurality of arcuate projections (64) extending outwardly from an exterior surface of the locking ring (34). As mentioned above, the interior chamber (3) of the valve body (2) presents a circular lip (63) and a plurality of arcuate projections (66) extending inwardly from the interior surface of the interior chamber (3). As best seen in FIG. 6, a gap (65) is defined within the interior chamber (3) between a top surface of the circular lip (63) and bottom surfaces of the projections (66). An arcuate slot (67) is formed between each pair of consecutive projections (66) extending from the interior surface of the interior chamber (3). The slots (67) are sized to accommodate for passage of the projections (64) of the locking ring (34). With the retaining member (30) positioned within the interior chamber (3) as discussed above, the locking ring (34) is positioned about the upper cylindrical portion (53) of the retaining member (30) such that a bottom surface of the locking ring (34) rests upon a bearing surface (35) of the retaining member (30). The locking ring (34) may then be driven vertically downwardly along the vertical axis (VA1) by applying a downwardly directed axial force to the locking ring (34) and the retaining member (30) to thereby overcome the upwardly directed axial force imparted upon the retaining member (30) by the resilient members (38). The retaining member (30) and the locking ring (34) may be moved downwardly such that the projections (64) of the locking ring (34) are passed through the slots (67) and until the projections (64) engage the top surface of the circular lip (63). The locking ring (34) may then be rotated in the direction of an arrow (72) shown in FIG. 7 such that the projections (64) are passed into the gap (65) so as to vertically align the projections (64) of the locking ring (34) with the projections (66) of the interior chamber (3) to thereby inhibit vertical movement of the locking ring (34). It should be appreciated that with locking ring (34) and retaining member (30) in this vertical position, the resilient members (38) are in a compressed state such that the resilient members (38) bear axially upwardly against an interior surface of the cylindrical recess (36) and axially downwardly against the top surface (44) of the plug (4) via the disc member (40) and the diaphragm (42). As will be discussed in more detail below, the atmosphere collar (74) of the upper assembly comprises a plurality of downwardly extending tabs (76). With projections (64, 66) aligned, the tabs (76) of the atmosphere collar (74) are configured to be received within the slots (67) to thereby prevent the locking ring (34) from inadvertently rotating in a direction opposite of the arrow (72) so as to prevent disengagement of the retaining member (30) and the atmosphere collar (74) from the interior chamber (3) of the valve body (2). ] As best seen in FIG. 5, the locking ring (34) comprises a plurality of threaded bores (69) that pass vertically through the locking ring (34). An adjusting screw (70) is threaded into each threaded bore (69) of the plurality of threaded bores (69). The adjusting screws (70) of the locking ring (34) are configured to extend through the locking ring (34) and bear against the bearing surface (35) of the retaining member (30). The adjustable nature of the adjusting screws (70) allows for the user to adjust the amount of force imposed upon the retaining member (30) by the adjusting screws (70) to thereby adjust the axial position of the retaining member (30) along the vertical axis (VA1) relative to the locking ring (34). It should be understood that adjustment of the axial position of the retaining member (30) will adjust an amount of compression of the resilient members (38) so as to adjust the downwardly directed axial force that the resilient members (38) apply to the plug (4). As best seen in FIG. 6, however, yet another circular lip (71) formed within the interior chamber (3) of the valve body (2) engages a bottom surface of a circular lip (78) of the retaining member (30) to thereby limit the amount by which the user may adjust the axial position of the retaining member (30) downwardly. 1] As best seen in FIG. 6, a circular sealing element (92) rests upon a top surface of the circular lip (71) and is compressed between a bottom surface of the circular lip (78) of the retaining member (30) and the top surface of the circular lip (71) of the interior chamber (3) to thereby provide a fluid seal between the circular lip (78) of the retaining member (30) and the circular lip (71) of the interior chamber (3). The sealing element (92) may comprise PTFE, graphite, or any other appropriate material. Because the axial position of the retaining member (30) may be adjusted, it should be understood that the amount of compressive force exerted upon diaphragm (42) by retaining member (30) and circular lip (41) of interior chamber (3) may be adjusted. It should also be understood that the axial force exerted on the top surface (44) of the plug (4) by the resilient members (38) via the disc member (40) and the diaphragm (42) may be adjusted to thereby adjust the axial position of the plug (4) along vertical axis (VA1) relative to the sleeve (18) and/or to adjust the fluid seal between the diaphragm (42) and the top surface (44) of the plug (4), the fluid seal between the exterior surface of the plug (4) and the interior surface of the sleeve (18), and/or the fluid seal between the exterior surface (21) of the sleeve (18) and the interior surface of the interior chamber (3). [000112] As mentioned above, during assembly, the sleeve (18) is positioned within the interior chamber (3) of the valve body (2) such that the openings (23, 25) of the sleeve (18) are substantially aligned with the openings (13, 15) of the passage (12) of the valve body (2). The plug (4) is then positioned within the hollow interior of the sleeve (18). The disc member (40) is then coupled with the diaphragm (42) such that the resilient tabs (50) of the disc member (40) engage and exert an inwardly directed radial bias on the cylindrical projection (46) of the diaphragm (42). The diaphragm (42), the disc member (40), and the resilient members (38) are then slid over the valve stem (28) of the plug (4) into the position shown in FIG. 1. The retaining member (30) is then slid over the valve stem (28) of the plug (4) such that the resilient members (38) are disposed within the cylindrical recess (36) of the retaining member (30). After this, the locking ring (34) is inserted into the interior chamber (3) by passing projections (64) of the locking ring (34) through the slots (67) formed between the projections (66) of the interior chamber (3) such that locking ring (34) rests upon the circular lip (63) of the interior chamber (3). After this, the locking ring (34) is rotated in the direction of arrow (72) to thereby position the projections (64) of the locking ring (34) within the gap (65) defined between the projections (66) and the circular lip (63) of the interior chamber (3) to thereby axially secure the locking ring (34) within the interior chamber (3). The axial position of the retaining member (30), and consequently the plug (4), may then be adjusted by adjusting screws (70) upwardly or downwardly. The atmosphere collar (74) may then be slid over the valve stem (28) via a through bore (75) formed in the atmosphere collar (74) such that the tabs (76) of the atmosphere collar (74) are disposed within the slots (67) of the interior chamber (3) to thereby prevent rotation of the locking ring (34) and such that the adjusting screws (70) are covered. It should be understood that the atmosphere collar (74) may be easily removed to thereby expose the adjusting screws (70).

[000113] C. Exemplary Fire-Safe Operation

[000114] FIGS. 8 and 9 show the valve (1) in a situation following dissipation or destruction of the sleeve (18) and the diaphragm (42) from, among other possible scenarios, exposure to heat, i.e. , a fire. After the sleeve (18) has dissipated, the resilient members (38) continue to bear against the top surface (44) of the plug (4) to thereby drive the plug (4) downwardly into the interior chamber (3) along the vertical axis (VAl) in the direction of an arrow (80). As discussed above, the interior chamber (3) of the valve body (2) includes a pair of sealing rings (20, 22) extending radially inwardly from the interior surface of the interior chamber (3) adjacent to the openings (13, 15) of the passage (12). The interior surfaces of the sealing rings (20, 22) are tapered such that the interior surfaces are defined by the similar angle (Θ1) relative to the vertical axis (VAl) just as the exterior surface (16) of the plug (4). Thus, as the plug (4) is driven downwardly via the resilient members (38), the exterior surface (16) of the plug (4) engages the interior surface of the sealing rings (20, 22) to thereby provide a metallic fluid seal between the exterior surface (16) of the plug (4) and the interior surface of the sealing rings (20, 22). It should be appreciated that in those embodiments of the present valve (1) in which the plug (4) and the sealing rings (20, 22) comprise a metallic material, such a fluid seal there between would provide a fire-safe fluid seal in the event of a fire or other incident causing the dissipation of the sleeve (18) and/or the diaphragm (42). In particular, such a fluid seal may allow for the valve (1) of the present example to comply with API 607, API 598, API 6FA, and/or ISO 10497 among other standards. 5] It may be appreciated that it is particularly important to drive the plug (4) downwardly within the interior chamber (3) with a considerable amount of force such that an effective fluid seal is formed between the exterior surface (16) of the plug (4) and the interior surfaces of the sealing rings (20, 22). It may also be appreciated that as a result of the comparatively large angle (Θ1) of the exterior surface (16) of the plug (4) and the interior surface of the sealing rings (20, 22) relative to the vertical axis (VAl), in the range between 4° and 6°, preferably in the range between 4.5° and 5.5°, and, in particular, essentially at 5°, a reliable fluid seal that satisfies the applicable global standards may be achieved in a simple and yet compact design. Finally, it should understood that all or a portion of the exterior surface (16) of the plug (4) and/or the interior surface of the sealing rings (20, 22) may be provided with features to enhance the fluid seal provided therebetween. For instance, all or a portion of the exterior surface (16) of the plug (4) and/or the interior surface of the sealing rings (20, 22) may be lapped. [000116] It should be understood that in those embodiments of the valve (1) configured for exposure to heat, the sealing element (92) which provides the fluid seal between the circular lip (78) of the retaining member (30) and the circular lip (71) of the interior chamber (3) may comprise a heat resistant material such as graphite, but may comprise any other appropriate heat resistant material. It should be understood that such a heat resistant sealing element (92) may inhibit emission of fluid and/or vapours from the interior chamber (3) in a situation following dissipation or destruction of the sleeve (18) and the diaphragm (42) from exposure to heat.

[000117] D. Exemplary Dynamic Upper Assembly with Additional Adjustable

Valve Stem Seal

[000118] In some embodiments of the valve (1) discussed above, it may be desirable to provide an alternative upper assembly configured to provide a further fluid seal about the valve stem (28). In such embodiments of the valve (1), it may be desirable to provide features that allow for adjustment of the compressive forces exerted upon the valve stem (28). For instance, it may be desirable to adjust the compressive forces exerted upon the valve stem (28) to thereby adjust the torque required to rotate the plug (4), to maintain the reliability of the fluid seal, etc. FIGS. 10-13 show such a valve (100) having such an alternative upper assembly. The upper assembly of the present example is configured to operate substantially similar to the upper assembly of the valve (1) discussed above except for the differences discussed below. In particular, and among other things, the upper assembly of the present example is operable to inhibit inadvertent displacement of the diaphragm (42) and to apply a downwardly directed axial force upon the top surface (44) of the plug (4) via the disc member (40) and the diaphragm (42).

[000119] FIGS. 10-13 show an exemplary valve (100), designed as a plug valve, and configured to operate substantially similar to valve (1) discussed above except for the differences discussed below. In particular, the valve (100), of the present example, is operable to regulate the flow of a fluid through the passage (12) formed in the valve body (2), either by closing the passage (12) or by restricting the passage (12) by a definite predetermined motion of the plug (4). A lower assembly of the valve (100) is configured to operate substantially similar to the lower assembly of the valve (1) discussed above. As with the valve (1) discussed above, the lower assembly of the valve (100) of the present example comprises the valve body (2), the sleeve (18), the plug (4), the resilient disc member (40), and the resilient diaphragm (42). It should be understood that the components of the lower assembly of the valve (100) are arranged, as discussed above, with regards to the valve (1). It should further be understood that the components of the lower assembly of the valve (100) are configured to interact and operate, as discussed above, with regards to the valve (1). 0] The upper assembly of the valve (100) comprises a plurality of resilient members (138) and a plurality of retaining components including a retaining member (130), a locking ring (134), a retaining disc (174) , and a sealing element (192); all of which are configured to operate substantially similar to the retaining member (30), the locking ring (34), the atmosphere collar (74), and the sealing element (92) discussed above respectively, except for the differences discussed below. The upper assembly of the valve (100) further comprises a gland follower (180). As best seen in FIG. 10, the retaining member (130) of the present example includes a central through bore (173) such that the retaining member (130) may be slid over the valve stem (28). The retaining member (130) comprises a cylindrical bore (131) formed in a top surface of the retaining member (130) and extending along a length of the central through bore (173). When the valve (100) is assembled, and with the retaining member (130) positioned about the valve stem (28) of the plug (4), the cylindrical bore (131) defines a gap between an exterior surface (55) of the valve stem (28) and an interior surface (128) of the cylindrical bore (131). A plurality of sealing elements (190) are disposed within this gap and are configured to provide a fluid seal between the exterior surface (55) of the valve stem (28) and the interior surface (128) of the cylindrical bore (131). Although a plurality of sealing elements (190) are described in the present example, any number of sealing elements (190) may be used. For instance, a single sealing element (190) may be used. The sealing elements (190) may comprise standard PTFE packing or graphite packing, V- Ring CHEVRON® packing, or any other appropriate type of packing. The retaining member (130) of the present example further comprises a plurality of threaded bores (135) which, as will be discussed in more detail below, provide for adjustment of an axially directed compressive force applied to the sealing elements (190) by the gland follower (180).

[000121] As best seen in FIG. 10, the retaining disc (174) of the present example includes a central through-bore (175) such that the retaining disc (174) may be slid over the valve stem (28). The through-bore (175) of the retaining disc (174) is further sized to receive the gland follower (180). The gland follower (180) comprises a cylindrical protrusion (182) and a central through bore (183) such that the gland follower (180) may be slid over the valve stem (28). As best seen in FIG. 6, when assembled, with the gland follower (180) positioned about the valve stem (28) of the plug (4), the cylindrical protrusion (182) is disposed within the cylindrical bore (131) of the retaining member (130) such that a bottom surface of the cylindrical protrusion (182) rests upon a top surface of the sealing elements (190). The gland follower (180) comprises a plurality of through-bores (184) each corresponding to a respective threaded bore (135) of the retaining member (130). A set screw (188) is rotatably disposed within each through- bore (184) of the plurality of through-bores (184) and threaded into a respective threaded bore (135) of the plurality of threaded bores (135) of the retaining member (130) to thereby secure the gland follower (180) to the retaining member (130). It should be understood that, as the set screws (188) are adjusted, an axial position of the gland follower (180) will be adjusted relative to the retaining member (130) along the vertical axis (VA1). It should therefore be appreciated that, as the set screws (188) are tightened, the axial position of the gland follower (180) will be adjusted axially downwardly thereby compressing the sealing elements (190) via the bottom surface of the cylindrical protrusion (182) within the gap defined between the exterior surface (55) of the valve stem (28) and the interior surface (128) of the cylindrical bore (131). As the sealing elements (190) are compressed, the sealing elements (190) are driven outwardly and inwardly within the gap thereby increasing the force applied to the exterior surface (55) of the valve stem (28) and the interior surface (128) of the cylindrical bore (131) and thereby adjusting the fluid seal there between.

[000122] FIGS. 12 and 13 show the valve (100) in a situation following dissipation or destruction of the sleeve (18) and the diaphragm (42) from, among other possible scenarios, exposure to heat, i.e., a fire. As explained above with reference to the valve (1), because the plurality of resilient members (138) bear against a top surface (44) of the plug (4), in the absence of the sleeve (18), the plug (4) is driven downwardly relative to the valve body (2) along the vertical axis (VA1) into the interior chamber (3) in the direction of an arrow (160) such that the exterior surface (16) of the plug (4) engages the interior surface of the plurality of sealing rings (20, 22) formed in the interior surface of the interior chamber (3) of the valve body (2) to thereby provide a fluid seal between the exterior surface (16) of the plug (4) and the interior surface of the sealing rings (20, 22). It should be appreciated that in those embodiments of the present valve (100) in which the plug (4) and the sealing rings (20, 22) comprise a metallic material, such a fluid seal therebetween would provide a fire-safe fluid seal in the event of a fire or other incident causing the dissipation of the sleeve (18) and/or the diaphragm (42). In particular, such a fluid seal may comply with API 607, API 598, API 6FA, and/or ISO 10497 among other standards.

[000123] It may be appreciated that it is particularly important to drive the plug (4) downwardly within the interior chamber (3) with a considerable amount of force such that an effective fluid seal is formed between the exterior surface (16) of the plug (4) and the interior surfaces of the sealing rings (20, 22). It may also be appreciated that as a result of the comparatively large angle (Θ1) of the exterior surface (16) of the plug (4) and the interior surface of the sealing rings (20, 22) relative to the vertical axis (VA1), in the range between 4° and 6°, preferably in the range between 4.5° and 5.5°, and, in particular, essentially at 5°, a reliable fluid seal that satisfies the applicable global standards is achieved in a simple and yet compact design. Finally, it should understood that all or a portion of the exterior surface (16) of the plug (4) and/or the interior surface of the sealing rings (20, 22) may be provided with features to enhance the fluid seal provided therebetween. For instance, all or a portion of the exterior surface (16) of the plug (4) and/or the interior surface of the sealing rings (20, 22) may be lapped.

[000124] It should be understood that in those embodiments of the valve (100) configured for exposure to heat, the sealing elements (190) which provide the fluid seal between the exterior surface (55) of the valve stem (28) and the interior surface (128) of the cylindrical bore (131), and the sealing element (192) which provides the fluid seal between a circular lip (178) of the retaining member (130) and the circular lip (71) of the interior chamber (3), may comprise a heat resistant material such as graphite, but may comprise any other appropriate heat resistant material. It should be understood that such heat resistant sealing elements (190, 192) may inhibit emission of fluid and/or vapours from the interior chamber (3) in a situation following dissipation or destruction of the sleeve (18) and the diaphragm (42) from exposure to heat.

[000125] II. Exemplary Plug Valve with Bolted Upper Assembly

[000126] FIGS. 14-30 illustrate an exemplary valve (200). At least part of the valve (200) may be constructed and operable in accordance with at least some of the teachings of EP 1155250 Bl, EP 0100629 Bl, EP 0087824 Bl, and EP 0032038 Bl. As described therein and as will be described in greater detail below, the valve (200) is operable to regulate the flow of a fluid through a passage (212) formed in the valve (200), either by closing the passage (212) or by restricting it by a definite predetermined motion of a flow-restricting-element, i.e., a plug (204). It should also be understood that the valve (200) may have various structural and functional similarities with the XOMOX® Sleeved Plug Valves, the XOMOX® Multi-Port Sleeved Plug Valves, the XOMOX® Jacketed Sleeved Plug Valves, the XOMOX® High Pressure Sleeved Plug Valves, the XOMOX® Full Port Sleeved Plug Valves, the XOMOX® HF Sleeved Plug Valves, the XOMOX® Cage Control Sleeved Plug Valves, the XOMOX® Easi-Sleeve Sleeved Plug Valves, and/or the XOMOX® Severe Service Valves [[Any others?]]. Furthermore, the valve (200) may have various structural and functional similarities with the devices taught in any of the other references that are cited and incorporated by reference herein.

[000127] A. Exemplary Lower Assembly

[000128] As best seen in FIGS. 14 and 15, the valve (200) is designed as a plug valve. A lower assembly of the valve (200) of the present example comprises a valve body (202), a sleeve (218), a plug (204), a resilient disc member (240), a resilient diaphragm (242), and a sealing element (292). The valve body (202) includes the passage (212) that passes through the valve body (202) from a first end (200A) of the valve body (202) to a second end (200B) of the valve body (202) along a longitudinal axis (LA2). The valve body (202) further includes an interior chamber (203) that extends internally along a vertical axis (VA2) within the valve body (202). As best seen in FIG. 15, the passage (212) intersects and passes through the interior chamber (203) thereby forming a pair of openings (213, 215) where the passage (212) intersects the interior chamber (203). As will be discussed in more detail below, the interior chamber (203) includes a tapered interior surface associated with the sleeve (218) to thereby provide a fluid seal about the openings (213, 215). Also, as will be discussed in more detail below, the plug (204) is rotatably disposed within the interior chamber (203) such that the plug (204) is free to rotate within the interior chamber (203) about the vertical axis (VA2) to thereby selectively open, close, or restrict the flow of fluid through the passage (212).

[000129] The valve body (202) includes a first flange (207) disposed at the first end (200A) of the valve body (202) and a second flange (209) disposed at the second end (200B) of the valve body (202). An inlet opening (208) is formed in the first flange (207) and provides access to the passage (212) formed in the valve body (202). An outlet opening (210) is formed in the second flange (209) and provides access to the passage (212) formed in the valve body (202). It should be understood that the flanges (207, 209) of the present example may comprise any appropriate type of flange, including but not limited to an RF flange, an FF flange, a SE connection, a BW connection, and/or a SW connection.

[000130] The valve (200) further includes the sleeve (218) disposed within the interior chamber (203). The sleeve (218) is pressed into the interior chamber (203) of the valve body (202) to thereby create an interference or friction fit between the sleeve (218) and the interior chamber (203) so as to inhibit movement of the sleeve (218) within the interior chamber (203). As will be discussed in more detail below, the sleeve (218) is configured to rotatably receive the plug (204) such that the plug (204) is operable to rotate within and relative to the sleeve (218) about the vertical axis (VA2). The sleeve (218) comprises plastic, in particular PTFE, but may comprise any other suitable material. The sleeve (218) defines a hollow conical-shaped interior, tapering downwardly from a larger diameter to a smaller diameter. An interior surface (219) of the sleeve (218) is tapered such that the interior surface (219) is defined by an angle (Θ2) relative to vertical axis (VA2). The angle (Θ2) of the present example is in the range between 4° and 6°, preferably in the range between 4.5° and 5.5°, and in particular essentially at 5°. An exterior surface (216) of the plug (204) is similarly tapered such that the exterior surface (216) is also defined by the angle (Θ2) relative to vertical axis (VA2). Such an angle may allow for a reduction in the torque required to rotate the plug (204) within the sleeve (218) as compared to plugs having an angle (Θ2) of 2° for example.

[000131] The sleeve (218) includes a pair of openings (223, 225) formed in a sidewall of the sleeve (218). The interior chamber (203) of the valve body (202) comprises a pair of sealing rings (220, 222) extending radially inwardly from the interior surface of the interior chamber (203) adjacent to the openings (213, 215) of passage (212). The sleeve

(218) is pressed into the interior chamber (203) of the valve body (202), such that the openings (223, 225) of the sleeve (218) are substantially aligned with the openings (213, 215) of passage (212) within the valve body (202), and such that the sealing rings (220, 222) are disposed within the openings (223, 225) of the sleeve (218) to thereby further inhibit movement of the sleeve (218) within the interior chamber (203).

[000132] As discussed above, the exterior surface (216) of the plug (204) is tapered in a manner similar to the sleeve (218) discussed above such that the exterior surface (216) of the plug (204) is defined by the angle (Θ2) relative to the vertical axis (VA2). Also, as discussed above, the sleeve (218) is configured to rotatably receive the plug (204) such that the plug (204) is operable to rotate within and relative to the sleeve (218) about the vertical axis (VA2). The plug (204) is thus held floatingly within the hollow interior of the sleeve (218) by engagement with the interior surface (219) of the sleeve (218). It should be understood that, because the exterior surface (216) of the plug (204) and the interior surface (219) of the sleeve (218) comprise tapered surfaces defined by the similar angle (Θ2), the exterior surface (216) of the plug (204) will contact the interior surface

(219) of the sleeve (218) across substantially an entire height (H2) of the sleeve (218) to thereby provide a fluid seal between the interior surface (219) of the sleeve (218) and the exterior surface (216) of the plug (204) such that, when the valve (200) is assembled, fluid may not pass between the plug (204) and the sleeve (218). It should be understood that as the plug (204) is driven downwardly into the sleeve (218), the tapered exterior surface (216) of the plug (204) will exert an outwardly directed force upon the sleeve (218). Such outward force will cause an exterior surface (221) of the sleeve (218) to bear against an interior surface of the interior chamber (203) to thereby provide a fluid seal between the interior surface of the interior chamber (203) and the sleeve (218). Such outward force will further cause the sleeve (218) to expand into the spaces within the interior chamber (203) of the valve body (202) adjacent to the sealing rings (220, 222) to thereby increase the engagement between the sleeve (218) and the sealing rings (220, 222) so as to further inhibit movement of the sleeve (218) within the interior chamber

(203) . As will be discussed in more detail below, the plug (204) may be driven further downward relative to the sleeve (218) to thereby adjust the fluid seal between the plug

(204) and the sleeve (218) and/or the fluid seal between the sleeve (218) and the interior surface of the interior chamber (203). ] The plug (204) comprises a passage (214) that passes completely through the plug (204). From the discussion above, it will be appreciated that the plug (204) is rotatable about the vertical axis (VA2) to thereby selectively open, close, or partially restrict the flow of fluid through the passage (212). In particular, the plug (204) is rotatable within the sleeve (218) between an open position and a closed position. As shown in FIG. 15, the passage (214) of the plug (204) is configured to substantially align with the passage (212) of the valve body (202) when the plug (204) is in the open position to thereby provide for the flow of fluid through the passage (212) of the valve body (202). With the plug (204) in the closed position, the passage (214) of the plug (204) is essentially orthogonal to the passage (212) of the valve body (202) such that the plug (204) blocks the flow of fluid through the passage (212) of the valve body (202) via the fluid seal formed between the plug (204) and the sleeve (218). It should be understood that, the plug (204) may be rotated manually via a lever or wheel among other mechanisms, and may additionally or alternatively be rotated mechanically via a pneumatic, hydraulic, or electric actuator among other devices. It should further be understood that the passage (214) of the plug (204) may comprise any shape, and need not necessarily match a shape of the passage (212) of the valve body (202). For instance, the passage (214) of the plug (204) may comprise a rectangular shape among any other appropriate shape.

[000134] A valve stem (228) extends upwardly from a top surface (244) of the plug (204) and is coupled, preferably integrally, thereto. The valve stem (228) extends vertically through a central through bore (273) of a cover (230) to an external space (249). The valve stem (228) is configured to provide a means by which a user may manually or mechanically rotate the plug (204) within the sleeve (218) about the vertical axis (VA2). For instance, a lever or wheel may be coupled with an exposed portion (229) of the valve stem (228) to thereby allow a user to manually rotate the plug (204). Additionally or alternatively, a pneumatic, hydraulic, or electric actuator may be mechanically coupled with the exposed portion (229) of the valve stem (228) to thereby allow a user to mechanically rotate the plug (204).

[000135] The interior chamber (203) of the valve body (202) presents a circular lip (241).

A top surface of the circular lip (241) presents a channel (243). The channel (243) of the present example comprises a rectangular profile but may comprise any appropriate profile. With the plug (204) disposed within the sleeve (218), the top surface of the circular lip (241) is substantially horizontally aligned with the top surface (244) of the plug (204). A resilient circular diaphragm (242) is disposed within the interior chamber (203) and rests upon the top surface (244) of the plug (204) and the top surface of the circular lip (241). As best seen in FIG. 16, the top surface (244) of plug (204) comprises a pair of circular projections (269). The circular projections (269) of the present example comprise trapezoidal profiles but may comprise any appropriately shaped profile. The circular projections (269) are configured to engage the diaphragm (242) to thereby inhibit inadvertent displacement of the diaphragm (242). As will be discussed in more detail below, inadvertent displacement of the diaphragm (242) is further inhibited by components of the upper assembly of the valve (200). A sealing element (292) is also disposed within the interior chamber (203) and also rests upon the top surface of the circular lip (241). An internal diameter of the sealing element (292) is larger than an exterior diameter of the diaphragm (242) such that the sealing element (292) may rest upon the top surface of the circular lip (241) without overlapping with the diaphragm (242). As will be discussed in more detail below, components of the upper assembly of the valve (200) are configured to compress the sealing element (292) against the top surface of the circular lip (241) to thereby provide a fluid seal between the circular lip (241) and the upper assembly.

[000136] The diaphragm (242) comprises an essentially cylindrical projection (246) extending from a center of the top surface of the diaphragm (242). The cylindrical projection (246) comprises a circular through bore (251) extending completely through the cylindrical projection (246) such that the valve stem (228) may be slidably and rotatably disposed within the cylindrical projection (246). As will be discussed in more detail below, an interior surface (248) of the cylindrical projection (246) is configured to bear against an exterior surface (255) of the valve stem (228) so as to provide a fluid seal between the cylindrical projection (246) of the diaphragm (242) and the valve stem (228). The diaphragm (242) of the present example may comprise PTFE, rubber, stainless steel, or any other appropriate material. It should be appreciated that, a retaining member (not shown) may be provided to substantially completely encompass the cylindrical projection (246) to thereby inhibit extrusion and/or excessive deformation of the diaphragm (242), in particular the cylindrical projection (246).

[000137] The resilient disc member (240) of the lower assembly is configured to provide a fluid seal between the cylindrical projection (246) of the diaphragm (242) and the valve stem (228). The disc member (240) comprises a plurality of radially inwardly biased resilient tabs (250) radially disposed about an interior portion of the disc member (240). The resilient tabs (250) are designed as individual tabs that are separated from each other by means of a plurality of slots (252). As best seen in FIG. 25, a top portion of the cylindrical projection (246) presents a radially outwardly extending projection (256). The projection (256) is configured to selectively couple the disc member (240) to the diaphragm (242) via engagement with the resilient tabs (250) of the disc member (240). Proper coupling of the disc member (240) and the diaphragm (242) ensures the reliability of the fluid seal between the cylindrical projection (246) of the diaphragm (242) and the valve stem (228) particularly during axial and/or radial movement of the plug (204). [000138] As discussed above, when assembled, the valve stem (228) of the plug (204) is slidably and rotatably disposed within the cylindrical projection (246). When coupled with the diaphragm (242), the resilient tabs (250) of the disc member (240) are configured to bear against an exterior surface (257) of the cylindrical projection (246) of the diaphragm (242) to thereby drive the cylindrical projection (246) radially inwardly against the exterior surface (255) of the valve stem (228). In particular, as indicated by an arrow (260) in FIG. 28, an inwardly directed radial force is exerted on the exterior surface (255) of the valve stem (228) by the resilient tabs (250) via the interior surface (248) of the cylindrical projection (246) of the diaphragm (242). This engagement between the interior surface (248) of the cylindrical projection (246) and the exterior surface (255) of the valve stem (228) is configured to provide a fluid seal between the cylindrical projection (246) of the diaphragm (242) and the valve stem (228).

[000139] The disc member (240) and resilient tabs (250) may comprise any appropriate resilient material, including, but not limited to spring steel. Although a one-piece design of the disc member (240) and the resilient tabs (250) has been shown, the cylindrical projection (246) of the diaphragm (242) can be pressed against the valve stem (228) by any appropriate method. For instance, a tension spring and/or an annular spring, among other devices/methods, may be used to drive the cylindrical projection (246) radially inwardly against the exterior surface (255) of the valve stem (228) in lieu of the resilient tabs (250).

[000140] B. Exemplary Dynamic Upper Assembly with Bolted Cover and

Adjustable Stem Seal

[000141] The upper assembly of the valve (200) of the present example comprises a plurality of resilient members (238) and a plurality of retaining components including a cover (230), a gland follower (280), and a plurality of sealing elements (290). As best seen in FIGS. 18 and 19, the cover (230) of the present example includes a central through bore (273) such that the cover (230) may be slid over the valve stem (228). The cover (230) comprises a plurality of through-bores (233) each corresponding to a respective threaded bore (235) formed in a top surface of the valve body (202). A bolt (234) is rotatably disposed within each through-bore (233) of the plurality of through- bores (233) and threaded into a respective threaded bore (235) of the valve body (202) to thereby secure the cover (230) to the valve body (202). Thus, the bolts (234) may be threaded into the threaded bores (235) to thereby selectively secure the cover (230) to the valve body (202). As will be appreciated from the discussion below, with the cover (230) secured to the valve body (202), the resilient members (238) of the upper assembly are in a compressed state such that the resilient members (238) bear axially upwardly against the cover (230) and axially downwardly against the top surface (244) of the plug (204) via the disc member (240) and the diaphragm (242). It should be understood that, as the bolts (234) are tightened or loosened, an axial position of the cover (230) will be adjusted relative to the valve body (202) along the vertical axis (VA2). Also, as will be appreciated from the discussion below, adjusting the axial position of the cover (230) may increase or decrease a compressive force applied to the sealing element (292) and/or the top surface of the diaphragm (242) by the bottom of the cover (230). 2] The cover (230) further includes a cylindrical recess (236) formed in a bottom surface of the cover (230). With the cover (230) secured to the valve body (202) as discussed above, the bottom surface of the cover (230) is configured to bear against a top surface of the diaphragm (242) to thereby compress the diaphragm (242) between the bottom surface of the cover (230) and the top surface of the circular lip (241) of the interior chamber (203). Such compression is configured to inhibit inadvertent displacement of the diaphragm (242). Such compression may further cause the diaphragm (242) to flow into the channel (243) formed in the top surface of the circular lip (241) to thereby further inhibit inadvertent displacement of the diaphragm (242). Thus, it should be appreciated that channel (243) is configured to inhibit inadvertent displacement of the diaphragm (242). As best seen in FIG. 20, the bottom surface of the cover (230) comprises a pair of circular channels (259) configured to engage the top surface of the diaphragm (242) to thereby further inhibit inadvertent displacement of the diaphragm (242) in addition to the channel (243) formed in the top surface of the circular lip (241). The channels (259) of the present example comprise rectangular profiles but may comprise any appropriate profiles. [000143] With the cover (230) secured to the valve body (202) as discussed above, the bottom surface of the cover (230) is further configured to compress the sealing element (292) between the bottom surface of the cover (230) and the top surface of the circular lip (241) to thereby provide a fluid seal between the cover (230) and the circular lip (241). As discussed above, as the bolts (234) are tightened or loosened, an axial position of the cover (230) will be adjusted relative to the valve body (202) along the vertical axis (VA2). It should be understood that adjusting the axial position of the cover (230) may increase or decrease the compressive force applied to the sealing element (292) to thereby adjust the fluid seal between the cover (230) and the circular lip (241). The sealing element (292) may comprise PTFE, graphite, or any other appropriate material.

[000144] As best seen in FIG. 19, the cylindrical recess (236) of the cover (230) comprises an open end (237). With the cover (230) secured to the valve body (202) as discussed above, the open end (237) of the cylindrical recess (236) opens downwardly such that it opens toward the interior chamber (203) of the valve body (202). The cylindrical recess (236) is configured to receive the plurality of resilient members (238). The resilient members (238) may comprise a plurality of Belleville washers, a single spring, a plurality of springs, or any other appropriate resilient biasing element or elements. When assembled, the resilient members (238) are configured to axially impinge upon and/or preload the plug (204) within the sleeve (218) to thereby drive the plug (204) downwardly within the sleeve (218) relative to and along the vertical axis (VA2). In particular, the resilient members (238) are configured to bear axially upwardly against a top surface (279) of the cylindrical recess (236) and axially downwardly against the top surface (244) of the plug (204) via the disc member (240) and the diaphragm (242). As best seen in FIG. 28, and as indicated by an arrow (258), this downwardly directed axial force is exerted upon the top surface (244) of the plug (204) by the resilient members (238) via the disc member (240) and the diaphragm (242) so as to compress the diaphragm (242) between the disc member (240) and the top surface (244) of the plug (204). It should therefore be understood that because the resilient members (238) cause the bottom surface of the diaphragm (242) to bear against the top surface (244) of the plug (204), a fluid seal with be provided therebetween. Furthermore, it should be appreciated from the discussion above, that this downwardly directed axial force exerted upon the plug (204) by the resilient members (238) is configured to further provide for the fluid seal between the exterior surface (216) of the plug (204) and the interior surface (219) of the sleeve (218) and/or the fluid seal between the exterior surface (221) of the sleeve (218) and the interior surface of the interior chamber (203).

[000145] The cover (230) comprises a cylindrical bore (231) formed in a top surface of the cover (230) and extending along a length of the central through bore (273). When the valve (200) is assembled, and with the cover (230) positioned about the valve stem (228) of the plug (204), the cylindrical bore (231) defines a gap between an exterior surface (255) of the valve stem (228) and an interior surface (247) of the cylindrical bore (231). A plurality of sealing elements (290) are disposed within this gap and are configured to provide a fluid seal between the exterior surface (255) of the valve stem (228) and the interior surface (247) of the cylindrical bore (231). The sealing elements (290) may comprise standard PTFE packing or graphite packing, V-Ring CHEVRON® packing, or any other appropriate type of packing.

[000146] As best seen in FIG. 22, the gland follower (280) of the present example comprises a downwardly extending cylindrical protrusion (282) and a central through bore (283) such that the gland follower (280) may be slid over the valve stem (228). When assembled, with the gland follower (280) positioned about the valve stem (228) of the plug (204), the cylindrical protrusion (282) is slidably and rotatably disposed within the cylindrical bore (231) of the cover (230) such that a bottom surface of the cylindrical protrusion (282) rests upon a top surface of the sealing elements (290). The gland follower (280) comprises a plurality of through-bores (284). Each through-bore (284) of the gland follower (280) is configured to substantially align with a respective threaded bore (245) formed in a top surface of the cover (230) (FIG. 18) when the gland follower (280) is positioned about the valve stem (228) of the plug (204). A set screw (288) is rotatably disposed within each through-bore (284) of the plurality of through-bores (284) and threaded into a respective threaded bore (245) of the cover (230) to thereby secure the gland follower (280) to the cover (230). It should be understood that, as the set screws (288) are adjusted, an axial position of the gland follower (280) will be adjusted relative to the cover (230) along the vertical axis (VA2). It should therefore be understood that, as the set screws (288) are tightened, the axial position of the gland follower (280) will be adjusted axially downwardly thereby compressing the sealing elements (290) via the bottom surface of the cylindrical protrusion (282) within the gap defined between the exterior surface (255) of the valve stem (228) and the interior surface (247) of the cylindrical bore (231). As the sealing elements (290) are compressed, the sealing elements (290) are driven outwardly and inwardly within the gap thereby increasing the force applied to the exterior surface (255) of the valve stem (228) and the interior surface (247) of the cylindrical bore (231) and thereby adjusting the fluid seal there between.

[000147] C. Exemplary Fire-Safe Operation

[000148] FIG. 30 shows the valve (200) in a situation following dissipation or destruction of the sleeve (218) and the diaphragm (242) from, among other possible scenarios, exposure to heat, i.e., a fire. After the sleeve (218) has dissipated, the resilient members (238) continue to bear against the top surface (244) of the plug (204) to thereby drive the plug (204) downwardly into the interior chamber (203) along the vertical axis (VA2) in the direction of an arrow (280). As discussed above, the interior chamber (203) of the valve body (202) includes a pair of sealing rings (220, 222) extending radially inwardly from the interior surface of the interior chamber (203) adjacent to the openings (213, 215) of the passage (212). The interior surfaces of the sealing rings (220, 222) are tapered such that the interior surfaces are defined by the similar angle (Θ2) relative to the vertical axis (VA2) just as the exterior surface (216) of the plug (204). Thus, as the plug (204) is driven downwardly via the resilient members (238), the exterior surface (216) of the plug (204) engages the interior surfaces of the sealing rings (220, 222) to thereby provide a metallic fluid seal between the exterior surface (216) of the plug (204) and the interior surface of the sealing rings (220, 222). It should be appreciated that in those embodiments of the present valve (200) in which the plug (204) and the sealing rings (220, 222) comprise a metallic material, such a fluid seal therebetween would provide a fire-safe fluid seal in the event of a fire or other incident causing the dissipation of the sleeve (218) and/or the diaphragm (242). In particular, such a fluid seal may allow for the valve (200) of the present example to comply with API 607, API 598, API 6FA, and/or ISO 10497 among other standards.

[000149] It may be appreciated that it is particularly important to drive the plug (204) downwardly within the interior chamber (203) with a considerable amount of force such that an effective fluid seal is formed between the exterior surface (216) of the plug (204) and the interior surfaces of the sealing rings (220, 222). It may also be appreciated that as a result of the comparatively large angle (Θ2) of the exterior surface (216) of the plug (204) and the interior surface of the sealing rings (220, 222) relative to the vertical axis (VA2), in the range between 4° and 6°, preferably in the range between 4.5° and 5.5°, and in particular essentially at 5°, a reliable fluid seal that satisfies the applicable global standards may be achieved in a simple and yet compact design. Finally, it should be understood that all or a portion of the exterior surface (216) of the plug (204) and/or the interior surface of the sealing rings (220, 222) may be provided with features to enhance the fluid seal provided therebetween. For instance, all or a portion of the exterior surface (216) of the plug (204) and/or the interior surface of the sealing rings (220, 222) may be lapped.

[000150] It should be understood that in those embodiments of the valve (200) configured for exposure to heat, the sealing elements (290) which provide the fluid seal between the exterior surface (255) of the valve stem (228) and the interior surface (247) of the cylindrical bore (231), and the sealing element (292) which provides the fluid seal between the bottom surface of the cover (230) and the circular lip (241) of the interior chamber (203), may comprise a heat resistant material such as graphite, but may comprise any other appropriate heat resistant material. It should be understood that such heat resistant sealing elements (290, 292) may inhibit emission of fluid and/or vapours from the interior chamber (203) in a situation following dissipation or destruction of the sleeve (218) and the diaphragm (242) from exposure to heat.

[000151] D. Exemplary Dynamic Upper Assembly with Bolted Cover and

Rotary Packing Seal [000152] In some embodiments of the valve (200) discussed above, it may be desirable to provide an alternative upper assembly configured to provide an alternative manner of sealing between the exterior surface (255) of the valve stem (228) and the cover (230). For instance, among other reasons, it may be desirable to provide an alternative manner of sealing between the exterior surface (255) of the valve stem (228) and the cover (230) so as to prevent exterior leakage of fluid in a variety of applications. FIGS. 31-54 show examples of valves (300, 400) having such alternative upper assemblies. The upper assemblies of the present examples are configured to operate substantially similar to the upper assembly of the valve (200) discussed above except for the differences discussed below. In particular, and among other things, the upper assembly of the present example is operable to inhibit inadvertent displacement of the diaphragm (242) and to apply a downwardly directed axial force upon the top surface (244) of the plug (204) via the disc member (240) and the diaphragm (242).

[000153] FIGS. 31-42 show an exemplary valve (300), designed as a plug valve, and configured to operate substantially similar to valve (200) discussed above except for the differences discussed below. In particular, the valve (300) of the present examples is operable to regulate the flow of a fluid through the passage (212) formed in the valve body (202), either by closing the passage (212) or by restricting the passage (212) by a definite predetermined motion of the plug (204). A lower assembly of the valve (300) is configured to operate substantially similar to the lower assembly of the valve (200) discussed above. As with the valve (200) discussed above, the lower assembly of the valve (300) of the present example comprises the valve body (202), the sleeve (218), the plug (204), the resilient disc member (240), the resilient diaphragm (242), and the sealing element (292). It should be understood that the components of the lower assembly of the valve (300) are arranged as discussed above with regards to the valve (200). It should further be understood that the components of the lower assembly of the valve (300) are configured to interact and operate as discussed above with regards to the valve (200).

[000154] The upper assembly of the valve (300) comprises a plurality of resilient members (338) and a plurality of retaining components including a cover (330), a compression ring (380), and a sealing element (390). The cover (330) of the present example is configured to operate substantially similar to the cover (230) discussed above except for the differences discussed below. In particular, among other things, the cover (330) is configured to be adjustably secured to the top surface of the valve body (202) such that the cover (330) may apply a compressive force to the sealing element (292) to thereby provide a fluid seal between a bottom surface of the cover (330) and the top surface of the circular lip (241) and a compressive force to the diaphragm (242) to thereby inhibit inadvertent displacement of the diaphragm (242). Furthermore, and as will be discussed in more detail below, the cover (330) provides a sealing surface against which a fluid seal may be provided with the valve stem (228). 5] As best seen in FIGS. 35 and 36, the cover (330) of the present example includes a central through bore (373) such that the cover (330) may be slid over the valve stem (228). As best seen in FIG. 36, the cover (330) further includes a cylindrical recess (336) formed in a bottom surface of the cover (330). With the cover (330) secured to the valve body (202) as discussed above with reference to the cover (230), the bottom surface of the cover (330) is configured to bear against the sealing element (292) and the top surface of the diaphragm (242) to thereby compress the diaphragm (242) between the bottom surface of the cover (330) and the top surface of the circular lip (241) of the interior chamber (203). The cylindrical recess (336) of the cover (330) comprises an open end (337). With the cover (330) secured to the valve body (202) as discussed above, the open end (337) of the cylindrical recess (336) opens downwardly such that it opens toward the interior chamber (203) of the valve body (202). As with the cylindrical recess (236) of the cover (230) discussed above, the cylindrical recess (336) of the cover (330) of the present example is configured to receive the plurality of resilient members (338) of the present example such that the resilient members (338) axially impinge upon and/or preload the plug (204). In particular, as with the resilient members (238) of the valve (200) discussed above, the resilient members (338) of the present example are configured to bear axially upwardly against a top surface (379) of the cylindrical recess (336) and axially downwardly against the top surface (244) of the plug (204) via the disc member (240) and the diaphragm (242). The resilient members (338) may comprise a plurality of Belleville washers, a single spring, a plurality of springs, or any other appropriate resilient biasing element or elements.

[000156] The cover (330) further comprises a cylindrical bore (331) formed in the top surface (379) of the cylindrical recess (336) and extending along a length of the central through bore (373). A top surface (332) of the cylindrical bore (331) is angled upwardly and radially inwardly. When the valve (300) is assembled, and with the cover (330) positioned about the valve stem (228) of the plug (204), the cylindrical bore (331) defines a gap between an exterior surface (255) of the valve stem (228) and an interior surface (329) of the cylindrical bore (331). A sealing element (390) is positioned within this gap and is configured to provide a fluid seal between the exterior surface (255) of the valve stem (228) and the interior surface (329) of the cylindrical bore (331). The sealing element (390) may comprise standard PTFE packing or graphite packing, or any other appropriate type of packing.

[000157] The compression ring (380) of the upper assembly includes a central through bore (381) such that the compression ring (380) may be slid over the valve stem (228). The compression ring (380) is configured to be press fit within the cylindrical bore (331) to thereby create an interference or friction fit between an exterior surface of the compression ring (380) and the interior surface (329) of the cylindrical bore (331). The exterior surface of the compression ring (380) may be knurled or otherwise prepared to provide for more efficient assembly and/or improved engagement between the compression ring (380) and the cylindrical bore (331). A top surface (382) of the compression ring (380) is angled downwardly and radially inwardly. Thus when the compression ring (380) is pressed within the cylindrical bore (331), the top surface (382) of the compression ring (380) is angled opposite of the top surface (332) of the cylindrical bore (331).

[000158] The sealing element (390) is positioned within the cylindrical bore (331) between the top surface (332) of the cylindrical bore (331) and the top surface (382) of the compression ring (380). A top surface (392) of the sealing element (390) is angled upwardly and radially inwardly substantially similar to the top surface (332) of the cylindrical bore (331) such that the top surface (392) of the sealing element (390) thereby mates with the top surface (332) of the cylindrical bore (331). A bottom surface (394) of the sealing element (390) is angled downwardly and radially inwardly substantially similar to the top surface (382) of the compression ring (380) such that the bottom surface (394) of the sealing element (390) thereby mates with the top surface (382) of the compression ring (380). Thus, with the sealing element (390) positioned within the cylindrical bore (331) between the top surface (332) of the cylindrical bore (331) and the top surface (382) of the compression ring (380), pressing of the compression ring (380) into the cylindrical bore (331) will cause compression of the sealing element (390). It should therefore be understood that, an axial position of the compression ring (380) may be adjusted relative to the cover (330) along the vertical axis (VA2). As the axial position of the compression ring (380) is adjusted upwardly along the vertical axis (VA2), the compressive force applied to the sealing element (390) will be increased. As the sealing element (390) is compressed, the sealing element (390) is driven outwardly and inwardly within the gap thereby increasing the force applied to the exterior surface (255) of the valve stem (228) and the interior surface (329) of the cylindrical bore (331), thereby adjusting the fluid seal there between. 9] FIG. 42 shows the valve (300) in a situation following dissipation or destruction of the sleeve (218) and the diaphragm (242) from, among other possible scenarios, exposure to heat, i.e., a fire. As explained above with reference to the valve (200), because the plurality of resilient members (338) of the present example bear against a top surface (244) of the plug (204), in the absence of the sleeve (218), the plug (204) is driven downwardly relative to the valve body (202) along the vertical axis (VA2) into the interior chamber (203) in the direction of an arrow (360) such that the exterior surface (216) of the plug (204) engages the interior surfaces of the plurality of sealing rings (220, 222) formed in the interior surface of the interior chamber (203) of the valve body (202) to thereby provide a fluid seal between the exterior surface (216) of the plug (204) and the interior surfaces of the sealing rings (220, 222). It should be appreciated that in those embodiments of the present valve (300) in which the plug (204) and the sealing rings (220, 222) comprise a metallic material, such a fluid seal therebetween would provide a fire-safe fluid seal in the event of a fire or other incident causing the dissipation of the sleeve (218) and/or the diaphragm (242). In particular, such a fluid seal may comply with API 607, API 598, API 6FA, and/or ISO 10497 among other standards.

[000160] It may be appreciated that it is particularly important to drive the plug (204) downwardly within the interior chamber (203) with a considerable amount of force such that an effective fluid seal is formed between the exterior surface (216) of the plug (204) and the interior surfaces of the sealing rings (220, 222). It may also be appreciated that as a result of the comparatively large angle (Θ2) of the exterior surface (216) of the plug (204) and the interior surface of the sealing rings (220, 222) relative to the vertical axis (VA2), in the range between 4° and 6°, preferably in the range between 4.5° and 5.5°, and, in particular, essentially at 5°, a reliable fluid seal that satisfies the applicable global standards may be achieved in a simple and yet compact design. Finally, it should understood that all or a portion of the exterior surface (216) of the plug (204) and/or the interior surface of the sealing rings (220, 222) may be provided with features to enhance the fluid seal provided therebetween. For instance, all or a portion of the exterior surface (216) of the plug (204) and/or the interior surface of the sealing rings (220, 222) may be lapped.

[000161] It should be understood that in those embodiments of the valve (300) configured for exposure to heat, the sealing element (390) which provides the fluid seal between the exterior surface (255) of the valve stem (228) and the interior surface (329) of the cylindrical bore (331), and the sealing element (292) which provides the fluid seal between the bottom surface of the cover (330) and the circular lip (241) of the interior chamber (203), may comprise a heat resistant material such as graphite, but may comprise any other appropriate heat resistant material. It should be understood that such heat resistant sealing elements (390, 292) may inhibit emission of fluid and/or vapours from the interior chamber (203) in a situation following dissipation or destruction of the sleeve (218) and the diaphragm (242) from exposure to heat.

[000162] E. Exemplary Dynamic Upper Assembly with Bolted Cover and

Rotary O-Ring Seal [000163] FIGS. 43-54 show an exemplary valve (400), designed as a plug valve, and configured to operate substantially similar to valve (200) discussed above except for the differences discussed below. In particular, the valve (400) of the present examples is operable to regulate the flow of a fluid through the passage (212) fonned in the valve body (202), either by closing the passage (212) or by restricting the passage (212) by a definite predetermined motion of the plug (204). A lower assembly of the valve (400) is configured to operate substantially similar to the lower assembly of the valve (200) discussed above. As with the valve (200) discussed above, the lower assembly of the valve (400) of the present example comprises the valve body (202), the sleeve (218), the plug (204), the resilient disc member (240), the resilient diaphragm (242), and the sealing element (292). It should be understood that the components of the lower assembly of the valve (400) are arranged as discussed above with regards to the valve (200). It should further be understood that the components of the lower assembly of the valve (400) are configured to interact and operate as discussed above with regards to the valve (200).

[000164] The upper assembly of the valve (400) comprises a plurality of resilient members (438) and a plurality of retaining components including a cover (430), a sealing element (490), and a metallic element (492). The cover (430) of the present example is configured to operate substantially similar to the cover (230) discussed above except for the differences discussed below. In particular, among other things, the cover (430) is configured to be adjustably secured to the top surface of the valve body (202) such that the cover (430) may apply a compressive force to the sealing element (292) to thereby provide a fluid seal between a bottom surface of the cover (430) and the top surface of the circular lip (241) and a compressive force to the diaphragm (242) to thereby inhibit inadvertent displacement of the diaphragm (242). Furthermore, and as will be discussed in more detail below, the cover (430) provides a sealing surface against which a fluid seal may be provided with the valve stem (228).

[000165] As best seen in FIGS. 47 and 48, the cover (430) of the present example includes a central through bore (473) such that the cover (430) may be slid over the valve stem (228). As best seen in FIG. 47, the cover (430) further includes a cylindrical recess (436) formed in a bottom surface of the cover (430). With the cover (430) secured to the valve body (202) as discussed above with reference to the cover (230), the bottom surface of the cover (430) is configured to bear against the sealing element (292) and the a top surface of the diaphragm (242) to thereby compress the diaphragm (242) between the bottom surface of the cover (430) and the top surface of the circular lip (241) of the interior chamber (203). The cylindrical recess (436) of the cover (430) comprises an open end (437). With the cover (430) secured to the valve body (202) as discussed above, the open end (437) of the cylindrical recess (436) opens downwardly such that it opens toward the interior chamber (203) of the valve body (202). As with the cylindrical recess (236) of the cover (230) discussed above, the cylindrical recess (436) of the cover (430) of the present example is configured to receive the plurality of resilient members (438) of the present example such that the resilient members (438) axially impinge upon and/or preload the plug (204). In particular, as with the resilient members (238) of the valve (200) discussed above, the resilient members (438) of the present example are configured to bear axially upwardly against an interior surface (479) of the cylindrical recess (436) and axially downwardly against the top surface (244) of the plug (204) via the disc member (240) and the diaphragm (242). The resilient members (438) may comprise a plurality of Belleville washers, a single spring, a plurality of springs, or any other appropriate resilient biasing element or elements. ] The cover (430) further includes a cylindrical recess (431) formed in an interior surface of the through bore (473). When the valve (400) is assembled, and with the cover (430) positioned about the valve stem (228) of the plug (204), the cylindrical recess (431) defines a gap between an exterior surface (255) of the valve stem (228) and an interior surface (429) of the cylindrical recess (431). A sealing element (490) is disposed within this gap and is configured to provide a fluid seal between the exterior surface (255) of the valve stem (228) and the interior surface (429) of the cylindrical recess (431). The sealing element (490) may comprise a standard rubber O-ring, or any other appropriate type of O-ring or sealing element. The metallic element (492) is also disposed within the gap between the exterior surface (255) of the valve stem (228) and the interior surface (429) of the cylindrical recess (431). The metallic element (492) ensures substantially constant metallic contact between the valve stem (428) and the cover (430). [000167] FIG. 54 shows the valve (400) in a situation following dissipation or destruction of the sleeve (218) and the diaphragm (242) from, among other possible scenarios, exposure to heat, i.e., a fire. As explained above with reference to the valve (200), because the plurality of resilient members (438) of the present example bear against a top surface (244) of the plug (204), in the absence of the sleeve (218), the plug (204) is driven downwardly relative to the valve body (202) along the vertical axis (VA2) into the interior chamber (203) in the direction of an arrow (460) such that the exterior surface (216) of the plug (204) engages the interior surfaces of the plurality of sealing rings (220, 222) formed in the interior surface of the interior chamber (203) of the valve body (202) to thereby provide a fluid seal between the exterior surface (216) of the plug (204) and the interior surface of the sealing rings (220, 222). It should be appreciated that in those embodiments of the present valve (400) in which the plug (204) and the sealing rings (220, 222) comprise a metallic material, such a fluid seal therebetween would provide a fire-safe fluid seal in the event of a fire or other incident causing the dissipation of the sleeve (218) and/or the diaphragm (242). In particular, such a fluid seal may comply with API 607, API 598, API 6FA, and/or ISO 10497 among other standards.

[000168] It may be appreciated that it is particularly important to drive the plug (204) downwardly within the interior chamber (203) with a considerable amount of force such that an effective fluid seal is formed between the exterior surface (216) of the plug (204) and the interior surfaces of the sealing rings (220, 222). It may also be appreciated that as a result of the comparatively large angle (Θ2) of the exterior surface (216) of the plug (204) and the interior surface of the sealing rings (220, 222) relative to the vertical axis (VA2), in the range between 4° and 6°, preferably in the range between 4.5° and 5.5°, and, in particular, essentially at 5°, a reliable fluid seal that satisfies the applicable global standards may be achieved in a simple and yet compact design. Finally, it should understood that all or a portion of the exterior surface (216) of the plug (204) and/or the interior surface of the sealing rings (220, 222) may be provided with features to enhance the fluid seal provided therebetween. For instance, all or a portion of the exterior surface (216) of the plug (204) and/or the interior surface of the sealing rings (220, 222) may be lapped. [000169] It should be understood that in those embodiments of the valve (400) configured for exposure to heat, the sealing element (490) which provides the fluid seal between the exterior surface (255) of the valve stem (228) and the interior surface (429) of the cylindrical recess (431), and the sealing element (292) which provides the fluid seal between the bottom surface of the cover (430) and the circular lip (241) of the interior chamber (203), may comprise a heat resistant material such as graphite, but may comprise any other appropriate heat resistant material. It should be understood that such heat resistant sealing elements (490, 292) may inhibit emission of fluid and/or vapours from the interior chamber (203) in a situation following dissipation or destruction of the sleeve (218) and the diaphragm (242) from exposure to heat.

[000170] F. Exemplary Static Upper Assembly with Bolted Cover

[000171] In some embodiments of the valve (200) discussed above, it may be desirable to provide an alternative upper assembly configured to provide an alternative manner of providing a downwardly directed axial force to the plug (204). Such an alternative upper assembly may further provide an alternative manner of sealing between the diaphragm (242) and the plug (204) and between the exterior surface (255) of the valve stem (228) and the cover (230). FIGS. 55-81 show examples of valves (500, 600) having such alternative upper assemblies. The upper assemblies of the present examples are configured to operate substantially similar to the upper assembly of the valve (200) discussed above except for the differences discussed below. In particular, and among other things, the upper assembly of the present example is operable to inhibit inadvertent displacement of the diaphragm (242) and to apply a downwardly directed axial force upon the top surface (244) of the plug (204) via the diaphragm (242).

[000172] FIGS. 55-66 show an exemplary valve (500), designed as a plug valve, and configured to operate substantially similar to valve (200) discussed above except for the differences discussed below. In particular, the valve (500) of the present examples is operable to regulate the flow of a fluid through the passage (212) formed in the valve body (202), either by closing the passage (212) or by restricting the passage (212) by a definite predetermined motion of the plug (204). A lower assembly of the valve (500) is configured to operate substantially similar to the lower assembly of the valve (200) discussed above. As with the valve (200) discussed above, the lower assembly of the valve (500) of the present example comprises the valve body (202), the sleeve (218), the plug (204), the resilient diaphragm (242), and the sealing element (292). It should be understood that the components of the lower assembly of the valve (500) are arranged as discussed above with regards to the valve (200) except for the differences discussed below. It should further be understood that the components of the lower assembly of the valve (500) are configured to interact and operate as discussed above with regards to the valve (200) except for the differences discussed below. The lower assembly of the valve (500) of the present example, however, does not include the resilient disc member (240) of the lower assembly of the valve (200). As will be understood from the discussion below, however, the upper assembly of the valve (500) is configured to perform particular functions of the resilient disc member (240). For instance, the upper assembly of the valve (500) is configured to drive the cylindrical projection (246) of the diaphragm (242) radially inwardly against the exterior surface (255) of the valve stem (228) to thereby provide a fluid seal between the cylindrical projection (246) of the diaphragm (242) and the valve stem (228).

[000173] The upper assembly of the valve (500) comprises a plurality of retaining components including a cover (530), a compression ring (590), and a resilient disc (540). The cover (530) of the present example is configured to operate substantially similar to the cover (230) discussed above except for the differences discussed below. In particular, among other things, the cover (530) is configured to be adjustably secured to the top surface of the valve body (202) such that the cover (530) may apply a compressive force to the sealing element (292) to thereby provide a fluid seal between a bottom surface of the cover (530) and the top surface of the circular lip (241) and a compressive force to the diaphragm (242) to thereby inhibit inadvertent displacement of the diaphragm (242).

[000174] As shown in FIGS. 59-61, the cover (530) of the present example includes a central through bore (573) such that the cover (530) may be slid over the valve stem (228). As best seen in FIGS. 60 and 61, the cover (530) further includes a cylindrical recess (536) formed in a bottom surface of the cover (530). With the cover (530) secured to the valve body (202) as discussed above with reference to the cover (230), the bottom surface of the cover (530) is configured to bear against a top surface of the diaphragm (242) to thereby compress the diaphragm (242) between the bottom surface of the cover (530) and the top surface of the circular lip (241) of the interior chamber (203). The cylindrical recess (536) of the cover (530) comprises an open end (537). With the cover (530) secured to the valve body (202) as discussed above, the open end (537) of the cylindrical recess (536) opens downwardly such that it opens toward the interior chamber (203) of the valve body (202). The cylindrical recess (536) of the cover (530) of the present example is configured to receive the compression ring (590). The compression ring (590) includes a central through bore (592) such that the compression ring (590) may be slid over the valve stem (228). The compression ring (590) is configured to axially impinge upon the plug (204). In particular, the compression ring (590) is configured to bear axially downwardly against the top surface (244) of the plug (204) via the resilient disc (540) and the diaphragm (242). As best seen in FIG. 65, as indicated by an arrow (558), this downwardly directed axial force is exerted upon the top surface (244) of the plug (204) by the compression ring (590) via the resilient disc (540) and the diaphragm (242) so as to compress the diaphragm (242) between the resilient disc (540) and the top surface (244) of the plug (204). It should therefore be understood that because the compression ring (590) causes the bottom surface of the diaphragm (242) to bear against the top surface (244) of the plug (204), a fluid seal with be provided there between.

[000175] The resilient disc (540) comprises a through bore (542) such that the resilient disc (540) may be slid over the valve stem (228) of the plug (204). When assembled, the resilient disc (540) is positioned between the top surface of the diaphragm (242) and a bottom surface of the compression ring (590). Among other things, the resilient disc (540) is configured to dissipate a force applied to the diaphragm (242) by the compression ring (590) across the diaphragm (242) and/or to provide rigidity to the diaphragm (242) so as to inhibit excessive deformation of the diaphragm (242).

[000176] An interior portion of the bottom surface of the compression ring (590) adjacent to the central through bore (592) of the compression ring (590) presents an angled surface (594) configured to radially impinge upon the exterior surface of the cylindrical projection (246) of the diaphragm (242). In particular, the compression ring (590) is configured to bear radially inwardly against the exterior surface of the cylindrical projection (246) of the diaphragm (242) so as to compress the diaphragm (242) between the angled surface (594) of the compression ring (590) and the exterior surface (255) of the valve stem (228) of the plug (204). It should therefore be understood that because the compression ring (590) causes the cylindrical projection (246) of the diaphragm (242) to bear against the exterior surface (255) of the valve stem (228) of the plug (204), a fluid seal with be provided therebetween. 7] The cover (530) comprises a plurality of threaded through-bores (584). A set screw (588) is threaded into each threaded through-bore (584) of the plurality of threaded through-bores (584). The set screws (588) are sized such that when threaded into the threaded through-bores (584), the set screws (588) extend through the cover (530) and contact a top surface of the compression ring (590). It should be understood that, as the set screws (588) are adjusted, an axial position of the compression ring (590) will be adjusted relative to the cover (530) along the vertical axis (VA2). In particular, as the set screws (588) are tightened, the axial position of the compression ring (590) will be adjusted axially downwardly thereby compressing the diaphragm (242) against the top surface (244) of the plug (204) via the bottom surface of the compression ring (590) and the resilient disc (540). As the diaphragm (242) is compressed against the plug (204), the fluid seal provided therebetween will also be adjusted. Furthermore, as the set screws (588) are tightened, the axial position of the compression ring (590) will be adjusted axially downwardly thereby compressing the cylindrical projection (246) of the diaphragm (242) against the exterior surface (255) of the valve stem (228) of the plug (204) via the angled surface (594) of the compression ring (590). As the cylindrical projection (246) of the diaphragm (242) is compressed against the exterior surface (255) of the valve stem (228), the fluid seal provided therebetween will also be adjusted. Finally, as the set screws (588) are tightened, the axial position of the plug (204) may be adjusted axially downwardly within the sleeve (218) relative to and along the vertical axis (VA2). It should be appreciated from the discussion above, that this downwardly directed axial force exerted upon the plug (204) is configured to adjust the fluid seal between the exterior surface (216) of the plug (204) and the interior surface (219) of the sleeve (218) and/or the fluid seal between the exterior surface (221) of the sleeve (218) and the interior surface of the interior chamber (203).

[000178] In some embodiments of valve (500), the resilient disc member (240) and the resilient members (238) discussed above, may be positioned between the bottom surface of the compression ring (590) and the top surface of the diaphragm (242). In such an embodiment of the valve (500), the plurality of resilient members (238) would bear axially downwardly against the top surface (244) of the plug (204) via the disc member (240) and the diaphragm (242) in a manner similar to that discussed above with reference to the valve (200). As discussed above, as the set screws (588) are adjusted, an axial position of the compression ring (590) will be adjusted relative to the cover (530) along the vertical axis (VA2). It should be understood that as the axial position of the compression ring (590) is adjusted, the force exerted upon the top surface (244) of the plug (204) by the resilient members (238) will also be adjusted. In particular, as the set screws (588) are tightened, the axial position of the compression ring (590) will be adjusted axially downwardly thereby compressing the resilient members (238) such that the force exerted upon the top surface (244) of the plug (204) by the resilient members (238) is increased.

[000179] G. Exemplary Static Upper Assembly with Bolted Cover and with

Additional Adjustable Valve Stem Seal

[000180] FIGS. 67-81 show an exemplary valve (600), designed as a plug valve, and configured to operate substantially similar to valve (200) discussed above except for the differences discussed below. In particular, the valve (600) of the present examples is operable to regulate the flow of a fluid through the passage (212) formed in the valve body (202), either by closing the passage (212) or by restricting the passage (212) by a definite predetermined motion of the plug (204). A lower assembly of the valve (600) is configured to operate substantially similar to the lower assembly of the valve (200) discussed above. As with the valve (200) discussed above, the lower assembly of the valve (600) of the present example comprises the valve body (202), the sleeve (218), the plug (204), the resilient diaphragm (242), and the sealing element (292). It should be understood that the components of the lower assembly of the valve (600) are arranged as discussed above with regards to the valve (200) except for the differences discussed below. It should further be understood that the components of the lower assembly of the valve (600) are configured to interact and operate as discussed above with regards to the valve (200) except for the differences discussed below. The lower assembly of the valve (600) of the present example, however, does not include the resilient disc member (240) of the lower assembly of the valve (200). As will be understood from the discussion below, however, the upper assembly of the valve (600) is configured to perform particular functions of the resilient disc member (240). For instance, the upper assembly of the valve (600) is configured to drive the cylindrical projection (246) of the diaphragm (242) radially inwardly against the exterior surface (255) of the valve stem (228) to thereby provide a fluid seal between the cylindrical projection (246) of the diaphragm (242) and the valve stem (228).

[000181] The upper assembly of the valve (600) comprises a plurality of retaining components including a cover (630), a compression ring (690), a gland follower (670), and a resilient disc (640). The cover (630) of the present example is configured to operate substantially similar to the cover (230) discussed above except for the differences discussed below. In particular, among other things, the cover (630) is configured to be adjustably secured to the top surface of the valve body (202) such that the cover (630) may apply a compressive force to the sealing element (292) to thereby provide a fluid seal between a bottom surface of the cover (630) and the top surface of the circular lip

(241) and a compressive force to the diaphragm (242) to thereby inhibit inadvertent displacement of the diaphragm (242).

[000182] As shown in FIGS. 71-74, the cover (630) of the present example includes a central through bore (673) such that the cover (630) may be slid over the valve stem (228). As best seen in FIGS. 73 and 74, the cover (630) further includes a cylindrical recess (636) formed in a bottom surface of the cover (630). With the cover (630) secured to the valve body (202) as discussed above with reference to the cover (230), the bottom surface of the cover (630) is configured to bear against a top surface of the diaphragm

(242) to thereby compress the diaphragm (242) between the bottom surface of the cover (630) and the top surface of the circular lip (241) of the interior chamber (203). The cylindrical recess (636) of the cover (630) comprises an open end (637). With the cover (630) secured to the valve body (202) as discussed above, the open end (637) of the cylindrical recess (636) opens downwardly such that it opens toward the interior chamber (203) of the valve body (202). The cylindrical recess (636) of the cover (630) of the present example is configured to receive the compression ring (690) and the gland follower (670). The compression ring (690) includes a central through bore (692) such that the compression ring (690) may be slid over the valve stem (228). The compression ring (690) is configured to axially impinge upon the plug (204). In particular, the compression ring (690) is configured to bear axially downwardly against the top surface (244) of the plug (204) via the resilient disc (640) and the diaphragm (242). As shown in FIG. 80, and as indicated by an arrow (658), this downwardly directed axial force is exerted upon the top surface (244) of the plug (204) by the compression ring (690) via the resilient disc (640) and the diaphragm (242) so as to compress the diaphragm (242) between the resilient disc (640) and the top surface (244) of the plug (204). It should therefore be understood that because the compression ring (690) causes the bottom surface of the diaphragm (242) to bear against the top surface (244) of the plug (204), a fluid seal with be provided therebetween.

[000183] The resilient disc (640) comprises a through bore (642) such that the resilient disc (640) may be slid over the valve stem (228) of the plug (204). When assembled, the resilient disc (640) is positioned between the top surface of the diaphragm (242) and a bottom surface of the compression ring (690). Among other things, the resilient disc (640) is configured to dissipate a force applied to the diaphragm (242) by the compression ring (690) across the diaphragm (242) and/or to provide rigidity to the diaphragm (242) so as to inhibit excessive deformation of the diaphragm (242).

[000184] An interior portion of the bottom surface of the compression ring (690) adjacent to the central through bore (692) of the compression ring (690) presents an angled surface (694) configured to radially impinge upon the exterior surface of the cylindrical projection (246) of the diaphragm (242). In particular, the compression ring (690) is configured to bear radially inwardly against the exterior surface of the cylindrical projection (246) of the diaphragm (242) so as to compress the diaphragm (242) between the angled surface (694) of the compression ring (690) and the exterior surface (255) of the valve stem (228) of the plug (204). It should therefore be understood that because the compression ring (690) causes the cylindrical projection (246) of the diaphragm (242) to bear against the exterior surface (255) of the valve stem (228) of the plug (204), a fluid seal with be provided therebetween.

[000185] As shown in FIGS. 75 and 76, the compression ring (690) comprises a cylindrical bore (691) formed in a top surface of compression ring (690) and extending along a length of the central through bore (692). When the valve (600) is assembled, and with the compression ring (690) positioned about the valve stem (228) of the plug (204), the cylindrical bore (691) defines a gap between an exterior surface (255) of the valve stem (228) and an interior surface (632) of the cylindrical bore (691). A plurality of sealing elements (696) are disposed within this gap and are configured to provide a fluid seal between the exterior surface (255) of the valve stem (228) and the interior surface (632) of the cylindrical bore (691). The sealing elements (696) may comprise standard PTFE packing or graphite packing, V-Ring CHEVRON® packing, or any other appropriate type of packing. The compression ring (690) further comprises a plurality of threaded bores (635) which, as will be discussed in more detail below, provide for adjustment of an axially directed compressive force applied to the sealing elements (696).

[000186] As mentioned above, the cylindrical recess (636) of the cover (630) of the present example is configured to receive the compression ring (690) and the gland follower (670). When assembled, the gland follower (670) is positioned within the cylindrical recess (636) between a top surface (639) of the cylindrical recess (636) and the compression ring (690). The gland follower (670) comprises a cylindrical protrusion (672) and a central through bore (673) such that the gland follower (670) may be slid over the valve stem (228). When assembled, with the gland follower (670) positioned about the valve stem (228) of the plug (204), the cylindrical protrusion (672) is disposed within the cylindrical bore (691) of the compression ring (690) such that a bottom surface of the cylindrical protrusion (672) rests upon a top surface of the sealing elements (696).

[000187] The cover (630) comprises a plurality of threaded through-bores (684). A set screw (688) is threaded into each threaded through-bore (684) of the plurality of threaded through-bores (684). The set screws (688) are sized such that when threaded into the threaded through-bores (684), the set screws (688) extend through the cover (630) and through a plurality of through-bores (676) formed in the gland follower (670) and contact a top surface of the compression ring (690). It should be understood that, as the set screws (688) are adjusted, an axial position of the compression ring (690) will be adjusted relative to the cover (630) along the vertical axis (VA2). In particular, as the set screws (688) are tightened, the axial position of the compression ring (690) will be adjusted axially downwardly thereby compressing the diaphragm (242) against the top surface (244) of the plug (204) via the bottom surface of the compression ring (690) and the resilient disc (640). As the diaphragm (242) is compressed against the plug (204), the fluid seal provided therebetween will also be adjusted. Furthermore, as the set screws (688) are tightened, the axial position of the compression ring (690) will be adjusted axially downwardly thereby compressing the cylindrical projection (246) of the diaphragm (242) against the exterior surface (255) of the valve stem (228) of the plug (204) via the angled surface (694) of the compression ring (690). As the cylindrical projection (246) of the diaphragm (242) is compressed against the exterior surface (255) of the valve stem (228), the fluid seal provided therebetween will also be adjusted. Finally, as the set screws (688) are tightened, the axial position of the plug (204) may be adjusted axially downwardly within the sleeve (218) relative to and along the vertical axis (VA2). It should be appreciated from the discussion above, that this downwardly directed axial force exerted upon the plug (204) is configured to adjust the fluid seal between the exterior surface (216) of the plug (204) and the interior surface (219) of the sleeve (218) and/or the fluid seal between the exterior surface (221) of the sleeve (218) and the interior surface of the interior chamber (203). ] The gland follower (670) comprises a plurality of through-bores (674) each corresponding to a respective threaded bore (635) of the compression ring (690). A set screw (693) is rotatably disposed within each through-bore (674) of the plurality of through-bores (674) and threaded into a respective threaded bore (635) of the plurality of threaded bores (635) of the compression ring (690) to thereby secure the gland follower (670) to compression ring (690). It should be understood that, as the set screws (693) are adjusted, an axial position of the gland follower (670) will be adjusted relative to the compression ring (690) along the vertical axis (VA2). It should therefore be understood that, as the set screws (693) are tightened, the axial position of the gland follower (670) will be adjusted axially downwardly thereby compressing the sealing elements (696) via the bottom surface of the cylindrical protrusion (672) within the gap defined between the exterior surface (255) of the valve stem (228) and the interior surface (632) of the cylindrical bore (691). As the sealing elements (696) are compressed, the sealing elements (696) are driven outwardly and inwardly within the gap thereby increasing the force applied to the exterior surface (255) of the valve stem (228) and the interior surface (632) of the cylindrical bore (691) and thereby adjusting the fluid seal there between. As shown in FIGS. 71, 72, 74, and 81 , the cover (630) comprises a plurality of through bores (677) which are configured to align with the through-bores (674) of the gland follower (670) so as to provide access to the set screws (693) with the cover (630) secured to the valve body (202). 9] In some embodiments of valve (600), the resilient disc member (240) and the resilient members (238) discussed above, may be positioned between the bottom surface of the compression ring (690) and the top surface of the diaphragm (242). In such an embodiment of the valve (600), the plurality of resilient members (238) would bear axially downwardly against the top surface (244) of the plug (204) via the disc member (240) and the diaphragm (242) in a manner similar to that discussed above with reference to the valve (200). As discussed above, as the set screws (688) are adjusted, an axial position of the compression ring (690) will be adjusted relative to the cover (630) along the vertical axis (VA2). It should be understood that as the axial position of the compression ring (690) is adjusted, the force exerted upon the top surface (244) of the plug (204) will also be adjusted. In particular, as the set screws (688) are tightened, the axial position of the compression ring (690) will be adjusted axially downwardly thereby compressing the resilient members (238) such that the force exerted upon the top surface (244) of the plug (204) by the resilient members (238) is increased. [000190] It should be understood that any of the resilient members/elements discussed above may comprise any predetermined preload, and may exert any predetermined amount of force onto a respective surface and/or component as discussed above.

[000191] III. Miscellaneous

[000192] It should be understood that although the versions of the valves discussed above are described as being designed as plug valves, the features discussed herein may be incorporated into any appropriate type of valve as would be apparent to one of ordinary skill in the art. For example, the features discussed herein may be applied to ball valves, needle valves, gate valves, globe valves, etc. Furthermore, any of the versions of valves described herein may include various other features in addition to or in lieu of those described above. By way of example only, any of the valves described herein may also include one or more of the various features disclosed in any of the various references that are incorporated by reference herein. It should also be understood that the teachings herein may be readily applied to any of the valves described in any of the other references cited herein, such that the teachings herein may be readily combined with the teachings of any of the references cited herein in numerous ways. Other types of valves into which the teachings herein may be incorporated will be apparent to those of ordinary skill in the art.

[000193] It should be appreciated that any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material. ] Having shown and described various embodiments of the present invention, further adaptations of the methods and systems described herein may be accomplished by appropriate modifications by one of ordinary skill in the art without departing from the scope of the present invention. Several of such potential modifications have been mentioned, and others will be apparent to those skilled in the art. For instance, the examples, embodiments, geometries, materials, dimensions, ratios, steps, and the like discussed above are illustrative and are not required. Accordingly, the scope of the present invention should be considered in terms of the following claims and is understood not to be limited to the details of structure and operation shown and described in the specification and drawings.