Gate valve with removable cartridge

Abstract

The gate valve (1) comprises a valve body (2) defining a valve body cavity (20) accessible through a top entry opening (50) of the valve; a removable bonnet (5) closing the top entry opening (50); a seal seat (31) positioned in the valve body cavity (20); a gate closing member (33) held by a closing member holder (34) and linearly movable relative to the valve body (2) and the seal seat (31); and a stem (6) having a first end connected to the closing member holder (34) and a second end protruding through the removable bonnet (5) and connected to a valve operating means (11).

Description

[Technical Field]

[0001] The present invention generally belongs to the technical field of gate valves. In particular, the present invention relates to a gate valve comprising a valve body accessible through a top entry opening, wherein both the gate closure member and each seal seat can be inserted into and removed from the valve body through the top entry opening. The gate valve of the present invention can be suitably configured as a valve having an extended structure, and a preferred application thereof includes, but is not limited to, cryogenic applications. [Background Art]

[0002] Gate valves are well known and widely used at present, particularly as shut-off valves, in both civil and industrial fields due to their advantageous hydrodynamic performance, especially the very small pressure drop when the valve is open and enabling large flow rate, as well as their relatively simple and compact structure.

[0003] In some industrial applications, there is a demand for valves that allow maintenance and inspection while installed in-line. For this purpose, valves having a top entry structure have been developed, in which the closure member and the respective seal seats can be inserted into and removed from the valve body through the top entry opening of the valve. Such a structure allows access to the interior of the valve body and the valve components most susceptible to wear, such as the closure member and seal seats, for maintenance, inspection or replacement without removing the valve from each line.

[0004] In particular, gate valves with a top-entry structure are known, in which, in addition to the gate closing member, a seal seat is also detachably housed within the valve body cavity. In this case, to handle these components, the bonnet closing the top-entry opening of the valve must first be removed. Simultaneously with or after the removal of the bonnet, the valve stem is removed together with the gate closing member. This gate closing member is usually supported by a closing member holder detachably connected to the end of the stem itself. At this point, the valve body cavity becomes freely accessible, and the seal seat can be removed. The valve can then be reassembled by performing the same steps as above in reverse order.

[0005] Although the aforementioned steps can be performed even when the valve is installed in line, it has been found that maintenance can actually be quite complex and time-consuming, due to the need to directly access the valve body cavity to remove and subsequently reposition the seal seat, and furthermore, the fact that the seal seat and closing member must be removed / inserted into the valve body cavity separately, i.e., in two different steps. This is particularly noticeable in valves with extension structures, but is not limited to them. In such valves, the greater distance between the top entry opening and the valve body cavity makes it more difficult to work inside the valve body cavity. [Overview of the project]

[0006] In view of the foregoing, the main object of the present invention is to provide a gate valve having a top entry opening, wherein both the gate closing member and each seal seat can be inserted into and removed from the valve body through the top entry opening, and furthermore, maintenance and inspection can be performed more easily and quickly than with conventional gate valves of the same type, even when installed in line.

[0007] More specifically, the object of the present invention is to provide a gate valve of the type described above, wherein its structure allows for the simplification and reduction of work performed inside the valve body for maintenance and inspection.

[0008] A further object of the present invention is to provide a gate valve that has the above-mentioned features, has the simplest possible structure, and can be manufactured at a competitive cost.

[0009] According to the present invention, these objectives are achieved by a gate valve having the features described in claim 1.

[0010] In particular, the present invention is A valve body having side walls and a bottom wall, the side walls having a fluid inlet port and a fluid outlet port having a common axis, and the side walls and bottom wall defining a valve body cavity accessible through the top entry opening of the valve, A removable hood that closes the top entry opening, A seal seat located inside the valve body cavity, A gate closing member is held by a closing member holder and is linearly movable relative to the valve body and seal seat in a plane perpendicular to the common axis of the fluid inlet port and the fluid outlet port, between a valve open position in which the gate closing member allows fluid flow through the valve body and a valve closed position in which the gate closing member engages tightly with the seal seat and obstructs fluid flow through the valve body. The present invention relates to a gate valve comprising a stem having a first end connected to a closing member holder and a second end protruding through a removable bonnet and connected to a valve operating means.

[0011] The seal seat is connected to each support component, which is detachably housed in the valve body cavity and defines a seat for housing the gate closing member and the closing member holder in the valve closed position. Thus, the gate closing member, the closing member holder, the seal seat, and the support component of the seal seat form a detachable closing member assembly, which, by acting on the support component of the seal seat, can be inserted as a whole into and removed from the valve body cavity through the top entry opening.

[0012] Within the scope of this specification and the following claims, the following definitions apply: "Longitudinal direction" or "in the longitudinal direction" means the direction parallel to the axis of the valve stem. "Axial direction" or "in the axial direction" means the direction parallel to the common axis of the inlet port and outlet port of the valve body. "Lateral direction" or "in the horizontal direction" means a direction perpendicular to the longitudinal direction and the axial direction.

[0013] These definitions apply to the assembled state of the valve, and, unless otherwise specified, also apply when considering each component separately and in the corresponding arrangement that would be expected when it is incorporated into the valve.

[0014] By providing a special support structure for a seal seat that is configured to also function as a housing for the gate closing member and the closing member holder, the gate valve of the present invention forms a removable component assembly (hereinafter referred to as the "closing member assembly") comprising the gate closing member and the seal seat. This assembly forms a cartridge that can be inserted integrally into and removed integrally from the valve body cavity through the top entry opening by directly or indirectly acting on, i.e., gripping, the support structure of the seal seat.

[0015] Therefore, the gate valve of the present invention is advantageous because the seal seat and the gate closing member can be inserted together into and removed together from the valve body cavity in a single operation. Thus, maintenance of the gate valve of the present invention is simplified and expedited when maintenance must be performed while the valve is installed in a line and / or when the valve has an extension structure, but is not limited to this, and especially when access to the valve body cavity and / or work inside the valve body cavity is difficult.

[0016] Furthermore, as will become clearer from the description of preferred embodiments of the present invention, the aforementioned features can be realized by a relatively simple design solution, and this design can be easily scaled to different valve sizes, thus having a favorable impact on manufacturing costs.

[0017] The support structure of the seal seat is preferably directly or indirectly detachably connected to the detachable bonnet, or is in direct or indirect longitudinal contact with the detachable bonnet.

[0018] This makes it possible to effectively and structurally counteract the drag of the seal seat support component that may occur, especially when the gate closing member is actuated to open the valve, and is therefore advantageous because it can stably and reliably maintain the correct positioning of the seal seat support component, and by extension the seal seat itself, in the valve body cavity.

[0019] The support structure of the seal seat comprises a side wall and a bottom wall having flat surfaces that define at least partially the seat portion, and an opening opposite the bottom wall. Through this opening, the gate closing member and the closing member holder can be inserted into and removed from the seat portion. The side wall is preferably provided with an opening oriented to detachably accommodate the seal seat, and comprises a main surface coaxial with the fluid inlet port and the fluid outlet port, and two mutually parallel flanks extending perpendicular to the main surface from a laterally opposite edge of the main surface.

[0020] The support structure of the seal seat preferably includes guide means directed to cooperate with the fitting guide means of the closing member holder in order to guide the movement of the gate closing member between the valve open position and the valve closed position.

[0021] Preferably, the side wall of the valve body has an inner side, that is, a side facing the valve body cavity, and this inner side is provided with a first flat surface perpendicular to the common axis of the fluid inlet port and fluid outlet port of the valve body, where the fluid outlet port opens into the valve body cavity, and a second flat surface axially opposite the first flat surface and inclined longitudinally with respect to the common axis, where the fluid inlet opening opens into the valve body cavity. When the valve is assembled, the seal seat abuts against the first flat surface, and the closing member holder abuts against the second flat surface by correspondingly longitudinally inclined flat contact surfaces in the valve closed position.

[0022] The first and second flat surfaces of the valve body sidewall as defined above give the valve body cavity a generally wedge-shaped structure when viewed in longitudinal section. This wedge-shaped structure is consistent with the similar structure of the closure member holder. Such a wedge-shaped structure is advantageous because it ensures proper positioning of the closure member assembly, particularly the seal seat, in the valve body cavity and facilitates centering of the closure member assembly when it is inserted into the valve body cavity.

[0023] In a preferred embodiment advantageous for valves intended for cryogenic applications or buried installation, the gate valve of the present invention may have an extension structure in which the valve stem is an extension stem, and the valve body is provided with a valve body extension that, together with the valve body, defines the internal chamber of the valve and defines the top entry opening.

[0024] In this case, it is preferable that the support structure of the seal seat is also provided with an extension of the support structure having a first longitudinal end detachably connected to the support structure of the seal seat and a second longitudinal end located near the top entry opening or at the top entry opening.

[0025] The support extension advantageously enables insertion / removal of the closing member assembly even in the case of an extended structure, by operating only through the top entry opening of the valve.

[0026] It is more preferable that the second longitudinal end of the support extension longitudinally abuts a removable bonnet or is connected to a removable upper member of the valve, wherein the upper member is located at the top entry opening and longitudinally abuts the removable bonnet directly or indirectly.

[0027] It is preferable that the support extension is formed of a tubular member surrounding the extension stem.

[0028] In this case, the gate valve of the present invention may further include a bellows seal disposed around the extension stem in an annular hollow space defined between the tubular member and the extension stem. In addition to the seal normally provided on the removable bonnet of the valve to prevent fluid leakage to the outside through the stem through-opening, such a seal can be advantageous as an additional sealing system in applications involving special fluids and / or hazardous fluids, for example cryogenic applications.

[0029] When such a bellows seal is provided, the gate valve of the present invention preferably further includes a seal plate that seals the tubular member at the second longitudinal end thereof, and the bellows seal preferably has a longitudinal end attached to one side surface of the seal plate. In this case, the seal plate may constitute the removable upper member of the valve.

[0030] In the case of an extended structure, particularly for cryogenic applications, it is convenient that the gate valve of the present invention further comprises a heat insulating assembly detachably accommodated in the internal chamber of the valve and configured to thermally insulate a first region of the internal chamber adjacent to the valve body from a second region of the internal chamber adjacent to the top entry opening.

[0031] This allows for advantageously limiting heat transfer, particularly convective heat transfer, between the valve internal chamber between the valve body and the closing member assembly, which become cryogenically cold under operating conditions, and the valve upper part, which has a valve bonnet and valve operating means that can become hotter, typically at room temperature, under operating conditions.

[0032] Preferably, the closing member assembly, the support structure extension of the seal seat support structure, the extension stem, and the insulation assembly form a detachable unit that can be inserted as a whole into and removed from the valve internal chamber of the valve through the top entry opening.

[0033] Therefore, it is advantageous that all removable valve assemblies and components can be inserted together and simultaneously into the valve internal chamber and removed together and simultaneously from the valve internal chamber. Thus, even in the presence of an insulating assembly, maintenance and inspection of the valve, including the components of the closing member assembly, can be performed particularly easily and quickly, as described above.

[0034] Furthermore, in cryogenic applications, it is advantageous for the gate valve of the present invention to be equipped with a jacket that surrounds the valve body and, if present, the extension of the valve body, and preferably forms a vacuumed hollow space (120). [Brief explanation of the drawing]

[0035] Further features and advantages of the present invention will become more apparent from the detailed description of preferred embodiments described below. These embodiments are shown for illustrative purposes only and do not limit the invention, and will be described with reference to the accompanying drawings. [Figure 1] Figure 1 is a schematic longitudinal cross-sectional view of a preferred embodiment of the gate valve according to the present invention. [Figure 2] Figure 2 is a magnified view of the details of the valve body shown in Figure 1. [Figure 3]Figure 3 is a cross-sectional view of the details of Figure 2 in a cross-sectional plane passing through the longitudinal central axis YY of the valve. [Figure 4] Figure 4 is a diagram similar to Figure 2, but with the valve in an open configuration. [Figure 5] Figure 5 is a schematic side view of the valve closing member assembly shown in Figure 1. [Figure 6] Figure 6 is a schematic cross-sectional view of the closing member assembly along the VI-VI section line in Figure 5. [Figure 7] Figure 7 is a schematic longitudinal cross-sectional view of the closing member assembly of Figure 5 along the section line VII-VII in Figure 6. [Figure 8] Figure 8 is similar to Figure 7, but shows a partially disassembled version. [Figure 9] Figure 9 is a schematic longitudinal cross-sectional view of the valve shown in Figure 1, with the bonnet and operating mechanism removed. [Figure 10] Figure 10 is a partially exploded perspective view of the valve in Figure 1, with the bonnet and operating mechanism removed, in a schematic longitudinal cross-section. [Figure 11] Figure 11 is a schematic perspective view of the detachable valve unit shown in Figure 1. [Figure 12] Figure 12 is a schematic perspective view showing the detachable unit of Figure 11 partially disassembled. [Figure 13] Figure 13 is a schematic longitudinal cross-sectional view of another preferred embodiment of the gate valve according to the present invention. [Figure 14] Figure 14 is a schematic longitudinal cross-sectional view of yet another preferred embodiment of the gate valve according to the present invention. [Modes for carrying out the invention]

[0036] Figures 1 to 12 show a first preferred embodiment of the gate valve according to the present invention, generally referred to as reference numeral 1. Valve 1 has an extended structure and is particularly suited for cryogenic applications. In this framework of "cryogenic applications," this refers to applications where the operating temperature is -150°C (123K) or lower.

[0037] Valve 1 comprises a valve body 2 having a valve body extension 4. The valve body extension 4 is positioned above the valve body 2 and, together with the valve body 2, defines the internal chamber 40 of valve 1. The interior of the internal chamber 40 and the valve body 2 is accessible through a top entry opening 50 of valve 1, which is defined by the free end of the valve body extension 4, located longitudinally opposite the end connected to the valve body 2. At the top entry opening 50, the valve body extension 4 is provided with a flange 51 for a removable bonnet 5 of the valve.

[0038] The valve body 2 is preferably integrally formed and includes side walls 21 and a bottom wall 22 that define the valve body cavity 20.

[0039] The side wall 21 of the valve body 2 has a fluid inlet port 211 and a fluid outlet port 212 having a common shaft XX. Each of the ports 211 and 212 is connected to a mounting component 23 for attaching the valve 1 to a line (not shown). In this embodiment, for example, the mounting component 23 is configured as a mounting component for a welded joint, but it can also be configured for any other type of mounting, particularly detachable, that is known to those skilled in the art.

[0040] The side wall 21 preferably has a cylindrical outer surface. Therefore, the valve body extension 4 preferably extends longitudinally above the valve body 2 and is composed of a cylindrical wall having a diameter equal to the outer diameter of the side wall 21.

[0041] As best shown in Figures 2, 4, and 10, the side wall 21 further has an inner surface facing the valve body cavity 20, which includes a first flat surface 213 where the fluid outlet port 212 opens into the valve body cavity 20, and a second flat surface 214 axially opposite the first flat surface 213 where the fluid inlet port 211 opens into the valve body cavity 20. The first flat surface 213 is positioned perpendicular to the axis XX, while the second flat surface 214 is inclined longitudinally with respect to the axis XX, so that the valve body cavity 20 is generally wedge-shaped when viewed in longitudinal section. More specifically, the second flat surface 214 forms an angle α (see Figure 4) with respect to a cross-section perpendicular to the axis XX, and this angle α is preferably in the range of 9° to 15°, for example, equal to 12°.

[0042] As shown in detail in Figure 1, and particularly in Figures 2 to 4, a seal seat 31 is located in the valve body cavity 20, oriented to be sealed and engaged by the gate closing member 33 of the valve 1. The seal seat 31 is connected to each support component 32 which is detachably housed in the valve body cavity 20, while the gate closing member 33 is held by a closing member holder 34, through which the gate closing member 33 is connected to the stem 6 of the valve 1.

[0043] The gate closing member 33 is linearly movable in the longitudinal direction, that is, in a plane perpendicular to the axis XX, with respect to the support component 32 of the seal seat 31, and therefore to the seal seat 31 itself and the valve body 2, between a valve open position (shown in Figures 1 to 3 and 9) in which the gate closing member 33 allows fluid to flow through the valve body 2, and a valve closed position (shown in Figure 4) in which the gate closing member 33 is tightly engaged with the seal seat 31 and obstructs fluid flow through the valve body 2.

[0044] A distinctive feature of valve 1 is that the support component 32 of the seal seat 31 is configured to form a seat portion 320 that accommodates the gate closing member 33 and the closing member holder 34 when the valve is closed. The support component 32, the seal seat 31, the gate closing member 33, and the closing member holder 34 constitute a closing member assembly, generally shown in the figures by reference numeral 3. This closing member assembly 3 can be inserted as a whole into the valve body cavity 2 through the top entry opening 50 and removed as a whole from the valve body cavity 2 by acting on the support component 32, as will be described in more detail with reference to Figures 9 to 12. Therefore, in the assembled state, the closing member assembly 3 forms a removable cartridge of valve 1, and the removable cartridge includes the main internal components that may require maintenance, inspection, or replacement, namely the seal seat 31 and the gate closing member 33. Thus, the seal seat 31 and the gate closing member 33 can be inserted into or removed from the valve body cavity 20 with a single operation, thereby simplifying and expediting maintenance of the valve 1.

[0045] As shown in detail in Figures 5 to 8, the support component 32 of the seal seat 31 is preferably integrally formed and includes a flat side wall and a bottom wall 322 that at least partially define a seat portion 320 that accommodates the gate closing member 33 and the closing member holder 34 in a pocket-like manner. These components can be inserted into or removed from the seat portion 320 through an opening 323 facing the bottom wall 322. The opening 323 is surrounded by its periphery by flanges 3231.

[0046] The side wall comprises a main surface 3211 having an opening 3212 oriented to detachably accommodate a seal seat 31, and two parallel flanks 3213 extending perpendicularly to the main surface 3211 from laterally opposing edges of the main surface 3211. At a position axially opposite to the main surface 3211, the side wall has a notch 3214, which exposes the rear side of the closing member holder 34 when the closing member holder 34 is housed in the seat portion 320 together with the gate closing member 33. When the support component 32 is housed in the valve cavity 20, the main surface 3211 of its side wall faces the first flat surface 213 of the side wall 21 of the valve body 2, and the seal seat 31, mounted in the opening 3212, abuts the first flat surface 213 in a sealed state. The opening 3212, and therefore the seal seat 31, is positioned coaxially with axis XX.

[0047] The seal seat 31 is housed in the opening 3212 in an axially fixed position and is held in place by a suitable retaining means 35, such as an elastic retaining ring.

[0048] The seal seat 31 is configured as an annular body having two sealing surfaces 311 and 312 that face each other in the axial direction. Specifically, the sealing surface 311 facing inward of the seat portion 320 defined by the support component 32 is oriented to be sealed and engaged by the gate closing member 33, while the sealing surface 312 facing outward of the seat portion 320 is oriented to be sealed and engaged with the valve body 2. A sealing ring 3121 is provided on the sealing surface 312, but if the gate closing member 33 has a sealing ring as in this embodiment, the sealing surface 311 does not need to have a sealing ring. In this case, sealing is performed directly on the surface of the sealing surface 311, which is probably covered with a layer of a suitable high-hardness material.

[0049] The gate closing member 33 is configured as a flat disc, and the flat disc has a sealing surface 331 that is oriented to engage with the seal seat 31 in a sealed manner, and a sealing ring 3311 is provided for that purpose. A connecting shank 332 is provided on the surface opposite to the sealing surface 331, and the gate closing member 33 can be detachably connected to the closing member holder 34 through this connecting shank 332.

[0050] The closing member holder 34 is preferably formed integrally from a generally disc-shaped body, and comprises a first side surface, i.e., a front surface 341, a second side surface, i.e., a rear surface 342, which is axially opposite to the first side surface, and a peripheral edge 343 that connects the first side surface 341 and the second side surface 342 in the axial direction. As described above, when the closing member holder 34 is completely housed in the seat portion 320 defined by the support component 32 of the seal seat 31 (valve closed position), the rear surface 342 of the closing member holder 34 is positioned at the notch 3214 and is freely exposed to the outside of the seat portion 320.

[0051] The front surface 341 is substantially flat and includes a circular receiving recess 3411 for accommodating the gate closing member 33. The receiving recess 3411 has a diameter substantially equal to the diameter of the gate closing member 33 and a depth shallower than the thickness of the gate closing member 33, so that when the gate closing member 33 is accommodated in the receiving recess 3411, its sealing surface 331 protrudes from the surface of the closing member holder 34.

[0052] At the center of the receiving recess 3411, the closing member holder 34 has an axial through hole 344 into which the connecting shank 332 of the gate closing member 33 is fitted. The connecting shank 332 can be fixed to the closing member holder 34 by a suitable detachable fastening means 36, such as a nut, which is attached to the end of the connecting shank 332 that protrudes from the rear surface 342 of the closing member holder 34.

[0053] The rear surface 342 of the closing member holder 34 has a flat surface 3421 that is inclined longitudinally with respect to the axial direction, at least at its lower longitudinal portion. When the valve 1 is assembled and the valve is in the closed position, the flat surface 3421 abuts against the aforementioned inclined flat surface 214 of the valve body cavity 20. More specifically, the flat surface 3421 forms an angle with respect to its cross-section equal to the inclination angle α of the flat surface 214 of the valve body cavity 20 (see Figure 8).

[0054] Therefore, the closing member holder 34 also has a wedge shape, at least in its lower longitudinal portion, that corresponds to the wedge shape of the valve body cavity 20 when viewed in a longitudinal cross-section.

[0055] In order to accurately and safely guide the movement of the gate closing member 33 relative to the seat portion 320 defined by the support component 32 of the seal seat 31, it is preferable that the closing member holder 34 is provided with a pair of parallel guide grooves 3431 (see Figure 6) facing each other laterally on its periphery 343. The guide grooves 3431 are formed inside the flanks 3213 of the side wall of the support component 32 of the seal seat 31 and are oriented to slidably accommodate a pair of guide projections 3215 (see Figures 6 to 8) having a corresponding fitting shape.

[0056] Furthermore, the closing member holder 34 is also provided with an engagement seat portion 3432 on its peripheral edge 343 for accommodating the stem 6.

[0057] The stem 6 of valve 1 is an extension stem, and its total length is preferably in the range of 350 mm to 2500 mm. In any case, the total length of the stem 6 is longer than the sum of the maximum longitudinal extension (height) of the valve body 2, the valve body extension 4, and the bonnet 5, so that the stem 6 protrudes outside the internal chamber 40 of valve 1 through the bonnet 5.

[0058] The stem 6 is preferably a single solid member, but it is also possible to make the stem 6 from multiple solid or hollow members. In either case, the stem 6 comprises a first end oriented to connect to the closing member holder 34, and in particular to engage detachably with the engaging seat portion 3432 of the closing member holder 34, but configured to engage integrally with longitudinal translational motion, and a second end oriented to connect to the actuarial means 11 of the valve 1, and for this purpose protruding to the outside of the valve 1 through the bonnet 5.

[0059] The actuation mechanism 11 may be a manual actuation mechanism, as shown in the example herein, or an electric actuation mechanism, both of which are known to those skilled in the art.

[0060] The detachable bonnet 5 may have any suitable configuration known to those skilled in the art and is not relevant to the present invention, so it will not be described in further detail here.

[0061] As is clear from Figure 1, in valve 1, or more generally in a gate valve according to the present invention having an extension configuration, it is preferable that the support component 32 of the seal seat 31 is provided with a support component extension 8 having a first longitudinal end 81 detachably connected to the support component 32 and a second longitudinal end 82 located near or at the top entry opening 50. In the assembled state of valve 1, the second longitudinal end 82 directly or indirectly abuts the bonnet 5 in the longitudinal direction. By using the support component extension 8, even in an extension configuration, it is possible to insert / remove the closing member assembly 3 by operation at the top entry opening 50 of the valve without reaching the valve body cavity 20. Furthermore, in the assembled state of valve 1, the support component extension 8 helps to counteract the possibility of the support component 32 being dragged when the gate closing member 33 is operated, and as a result helps to stably hold the support component 32 and the seal seat 31 together in the correct position within the valve body cavity 20.

[0062] In the embodiment shown herein, the support structure extension 8 is preferably made of a cylindrical tubular member, which coaxially surrounds the stem 6 and forms an annular hollow space 80 around it.

[0063] Each flange 811 (best shown in Figures 11 and 12) is provided at the first longitudinal end 81 of the tubular member 8, and these flanges 811 are detachably connected to the flange 3231 at the opening 323 of the support component 32 by screw fastening means, in this case by screws 14. Each flange 821 is provided at the second longitudinal end 82 of the tubular member 8, and this end is closed by a seal plate 820. The seal plate 820 has a through hole in the center through which the stem 6 passes and protrudes. In the assembled state of the valve 1, the seal plate 820 seals and engages around the flange 51 of the top entry opening 50 of the valve and directly contacts the bonnet 5 on its upper surface. The seal plate 820 is attached to the second longitudinal end 82 at its flange 821, for example by welding.

[0064] Preferably, a bellows seal 9 surrounding the stem 6 is present in the annular hollow space 80. The bellows seal comprises a longitudinal end attached, for example, by welding to the lower surface of the seal plate 820, and a second end attached, for example, by welding to a ring 91 which is essential for translational motion with the stem 6.

[0065] Valve 1 further includes an insulating assembly 7 that is detachably housed in the internal chamber 40 between the valve body 2 and the top entry opening 50. The insulating assembly 7 helps to thermally isolate a first region of the internal chamber 40 adjacent to the valve body 2, where the operating conditions are at cryogenic temperatures, from a second region of the internal chamber 40 adjacent to the top entry opening 50 and bonnet 5, where the operating temperature may instead be higher, such as room temperature.

[0066] In particular, the thermal insulation assembly 7 is configured to substantially limit heat transfer by conduction and convection that may occur in the internal chamber 40 due to the temperature difference between the two aforementioned regions.

[0067] The thermal insulation assembly 7 has an overall cylindrical annular structure, concentrically surrounding the aforementioned support structure extension 8, and is integrated with the support structure extension 8.

[0068] More specifically, the thermal insulation assembly 7 has a cylindrical annular shape and includes a housing chamber 71 that is arranged coaxially with the support structure extension 8.

[0069] The containment chamber 71 is filled with a solid thermal insulation material 72, such as betronite G10-FR4. Preferably, the thermal insulation material 72 forms a solid body consisting of one or more components.

[0070] In the lateral direction, i.e., laterally, the containment chamber 71 is defined on the inside by the tubular member 8 and on the outside by the cylindrical wall 712. In the longitudinal direction, i.e., at the top and bottom, the containment chamber 71 is defined by the flange 821 of the tubular member 8 and by a flat annular wall 713 parallel to the flange 821, respectively.

[0071] The tubular member 8, the cylindrical wall 712, and the annular wall 713 are firmly connected to each other, for example by welding, and they work together to form a rigid support and housing structure for the thermal insulation material 72.

[0072] Preferably, the cylindrical wall 712 has an outer diameter slightly smaller than the inner diameter of the valve body extension 4 that defines the internal chamber 40. Considering such minimal lateral clearance, the cross-sectional area of ​​the free volume of the internal chamber 40 can be considered to be substantially completely occupied by the adiabatic assembly 7.

[0073] The heat insulating assembly 7 preferably has a length in the range of 0.65L to 0.85L, where L is the total length of the internal chamber 40 of the valve 1, i.e., the valve body extension 4.

[0074] As is clear from the above, the closing member assembly 3, the support structure extension 8, the seal plate 820, the bellows seal 9, the heat insulation assembly 7, and the stem 6 form a detachable unit 10, which is also shown separately in Figures 10 and 11. This unit 10 can be inserted as a whole into the internal chamber 40 of the valve 1 by operating the seal plate 820 at the top entry opening 50 of the valve, and can also be removed as a whole from the internal chamber 40.

[0075] For this purpose, the seal plate 820 is preferably provided with fixed or detachable attachment means for facilitating the gripping and handling of the detachable unit 10 by hand or by a lifting device. In the embodiment shown herein, for example, the seal plate has a pair of threaded blind holes 8201 on its upper surface, which are shown in Figures 1 and 9 but omitted in Figures 10 to 12 for clarity. Eye bolts 13 can be temporarily screwed into these blind holes 8201 (see Figure 9).

[0076] The extended structure, even when the heat insulating assembly 7 is present, allows the aforementioned internal structure of the valve 1 to be removed and inserted particularly easily and quickly for maintenance, inspection, or replacement work by operating only the top entry opening 50 of the valve, that is, without directly reaching the valve body cavity 20.

[0077] Valve 1 is conveniently provided with a jacket 12 that surrounds the valve body 2, the valve body extension 4, and optionally part of the mounting component 23, thereby creating a vacuumable hollow space 120 around these components. At the top entry opening 50, the hollow space 120 is closed by a flange 51 that forms the support and fastening base of the bonnet 5. The jacket 12 can be omitted when valve 1 is intended to operate in an environment that is itself insulated, such as a so-called "cold box".

[0078] Referring particularly to Figures 9 to 12, the steps for removing the detachable unit 10, and consequently the closing member assembly 3, from the valve 1 will be described in more detail below as an example.

[0079] In the first step, the bonnet 5 is removed to expose the upper surface of the seal plate 820 so that the top entry opening 50 of the valve is clear.

[0080] In the next step, screw the eyebolt 13 into the threaded blind hole 8201 (Figure 9).

[0081] In the next step, the detachable unit 10, which is formed by the closing member assembly 3, the support structure extension 8, the seal plate 820, the bellows seal 9, the insulation assembly 7, and the stem 6, is removed from the valve's internal chamber 40 by hand or with the assistance of a suitable lifting device and using the eyebolt 13 (Figure 10).

[0082] Once the detachable unit 10 is removed from the valve 1, the detachable unit 10 can be disassembled. In particular, by removing the screw 14 that connects the flange 3231 of the support component 32 to the flange 811 of the support component extension 8, the support component 32 of the seal seat 31 can be separated from the detachable unit 10 (Figure 12). Once the support component 32 is removed, the closing member holder 34 can be freely accessed, and by disengaging it from the stem 6, this component can also be separated from the detachable unit 10.

[0083] At this stage, it becomes possible to freely work on the support structure 32 of the seal seat 31 and the closing member holder 34 on-site or in the factory for inspection, maintenance, or replacement of the seal seat 31 and / or gate closing member 33.

[0084] To reassemble the detachable unit 10 and reinsert it into valve 1, perform the same steps described above in reverse order.

[0085] Figure 13 shows another preferred embodiment of the gate valve according to the present invention, which is generally indicated by reference numeral 1'. Elements identical or functionally equivalent to those in the embodiments of Figures 1 to 12, particularly the valve body 2 and the closing member assembly 3, are indicated by the same reference numerals and are not described further here.

[0086] Valve 1' still has an extension structure, but it lacks the insulating assembly located in the internal chamber 40, the jacket surrounding the valve body 2 and the valve body extension 40, and the bellows seal surrounding the stem 6. Valve 1' is suitable for general applications requiring an extension structure, such as applications involving buried installation.

[0087] Similar to the embodiments described above, in valve 1', the support component 32 of the seal seat 31 also has a support component extension 8. The support component extension 8 is preferably made of a cylindrical tubular member, which coaxially surrounds the stem 6 to form an annular hollow space 80 around it. The first longitudinal end 81 of the support component extension 8, which has a flange 811, is detachably connected to the support component 32 itself, and the second longitudinal end 82 of the support component extension 8, which has a flange 821, is located in the top entry opening 50 of the valve.

[0088] However, in this case, the support structure extension 8 has a length such that, in the assembled state of the valve 1', its longitudinal end 82 directly abuts the bonnet 5 in the longitudinal direction. This is because a seal plate is not required to close the longitudinal end 82 itself. The flange 821 of the longitudinal end 82 also has a threaded blind hole, or possibly a through hole 8201, for attaching the eyebolt 13.

[0089] In valve 1', the closing member assembly 3, the support structure extension 8 of the support structure 32 of the seal seat 31, and the stem 6 form a detachable unit 10'. This detachable unit 10' can be inserted as a whole into the internal chamber 40 of valve 1' and removed as a whole from the internal chamber 40 by operating the longitudinal end 82 of the support structure extension 8 at the top entry opening 50 of the valve.

[0090] The detachable unit 10', as a result, the closing member assembly 3 can be removed from valve 1' and inserted into valve 1' according to the same steps described with respect to valve 1, and can also be disassembled and reassembled.

[0091] Figure 14 shows yet another preferred embodiment of the gate valve according to the present invention, which is generally indicated by reference numeral 1''. Elements identical or functionally equivalent to those in the embodiments of Figures 1 to 12, particularly the valve body 2 and the closing member assembly 3, are indicated by the same reference numerals and are not described further here.

[0092] Valve 1'' has a standard, i.e., unextended structure. Specifically, valve 1'' is equipped with a standard stem 6'', where "standard stem" means a stem with a length of less than 350 mm, and valve 1'' does not have either a valve body extension for the valve body 2 or a support structure extension for the support structure 32 of the seal seat 31.

[0093] The interior of the valve body 2 can be accessed through a top entry opening 50'' defined by the valve body 2 itself and closed by the removable bonnet 5 of the valve 1''.

[0094] In this case, the support component 32 of the seal seat 31 is detachably connected to the bonnet 5. More specifically, a connecting flange 3231 surrounding the opening 323 of the support component 32 is bolted to a pair of pins 15'' that project longitudinally from the underside of the bonnet 5. This connection prevents the support component 32 from being dragged longitudinally when the gate valve 33 is operated, and integrates the support component 32, and consequently the closing member assembly 3, with the bonnet 5. As a result, removing the closing member assembly 3 from or inserting it into the valve body 2 can be done simultaneously with removing the bonnet 5 from or installing it on the valve body 2.

[0095] For example, to remove the closing member assembly 3 from the valve 1'', it is only necessary to remove the bonnet 5 together with the stem 6''. After separating the detachable unit formed by the bonnet 5, closing member assembly 3, and stem 6'' from the valve body 2, this unit can be disassembled. In particular, by releasing the bolt fastening connection that connects the flange 3231 of the support component 32 to the pin 15'' of the bonnet 5, the support component 32 of the seal seat 31 can be removed from the bonnet 5. Once the support component 32 is removed, the closing member holder 34 can be freely accessed and disengaged from the stem 6'' to remove it from the detachable unit 10. At this point, it is possible to freely work on the support component 32 of the seal seat 31 and the closing member holder 34 in the field or factory for inspection, maintenance, or replacement of the seal seat 32 and / or gate closing member 33.

[0096] To reassemble the detachable unit formed by the bonnet 5, the closing member assembly 3, and the stem 6'' and to reinsert it into the valve 1'', perform the same steps described above in reverse order.

[0097] As an alternative to the detachable connection between the support component 32 of the seal seat 31 and the bonnet 5 described above, in the valve 1'', it is also conceivable that the support component 32 simply abuts directly or indirectly against the bonnet 5, according to a design solution similar to that implemented in the valve embodiment of the present invention described above.

[0098] As is clear from the above, the present invention provides a gate valve that has a top entry opening and allows for particularly easy and rapid maintenance and inspection, even in an in-line installation state and / or in an extended valve structure. These features are achieved with a particularly simple structure by arranging the internal components of the valve in a special way and in relation to each other so that a closing member assembly or cartridge can be formed that includes both a seal seat and a gate closing member, and can be inserted integrally into and removed integrally from the valve through the top entry opening.

Claims

1. A valve body (2) having a side wall (21) and a bottom wall (22), the side wall (21) being provided with a fluid inlet port (211) and a fluid outlet port (212) having a common axis (X-X), and the side wall (21) and the bottom wall (22) defining a valve body cavity (20) accessible through the top entry opening (50; 50'') of the valve, A removable bonnet (5) that closes the top entry opening (50; 50'), The seal seat (31) is located in the valve body cavity (20), The gate closing member (33) is held by a closing member holder (34) and is linearly movable relative to the valve body (2) and the seal seat (31) in a plane perpendicular to the common axis (X-X) of the fluid inlet port (211) and the fluid outlet port (212), between a valve open position in which the gate closing member (33) allows fluid to flow through the valve body (2) and a valve closed position in which the gate closing member (33) engages tightly with the seal seat (31) and obstructs fluid flow through the valve body (2), The system comprises a stem (6; 6'') having a first end connected to the closing member holder (34) and a second end protruding through the detachable bonnet (5) and connected to the valve operating means (11), The seal seat (31) is connected to each support component (32) which is detachably housed in the valve body cavity (20), The support component (32) of the seal seat (31) defines a seat portion (320) that accommodates the gate closing member (33) and the closing member holder (34) in the valve closed position, The gate valve (1;1';1'') comprises the gate closing member (33), the closing member holder (34), the seal seat (31), and the support component (32) of the seal seat (31), which, by acting on the support component (32) of the seal seat (31), form a removable closing member assembly (3) that can be inserted integrally into the valve body cavity (20) and removed integrally from the valve body cavity (20) through the top entry opening (50;50'').

2. The gate valve (1;1';1'') according to claim 1, wherein the support component (32) of the seal seat (31) is directly or indirectly detachably connected to the detachable bonnet (5), or is in direct or indirect longitudinal contact with the bonnet (5).

3. The support component (32) of the seal seat (31) comprises side walls (3211, 3213) and a bottom wall (322) having flat surfaces that define at least partially the seat portion (320), and an opening (323) facing the bottom wall (322), and the gate closing member (33) and the closing member holder (34) can be inserted into and removed from the seat portion (320) through the opening (323), and the side walls (321 A gate valve (1;1';1'') according to any one of the preceding claims, comprising a main surface (3211) coaxial with the fluid inlet port (211) and the fluid outlet port (212), having an opening (3212) oriented to accommodate the seal seat (31), and two mutually parallel flanks (3213) extending perpendicularly to the main surface (3211) from laterally opposing edges of the main surface (3211).

4. The gate valve (1;1';1'') according to any one of the preceding claims, wherein the support component (32) of the seal seat (31) comprises a guide means (3215) directed to cooperate with the fitting guide means (3431) of the closing member holder (34) in order to guide the movement of the gate closing member (33) between the valve open position and the valve closed position.

5. The side wall (21) of the valve body (2) is such that the fluid outlet port (212) opens into the valve body cavity (20), and there is a first flat surface (213) perpendicular to the common axis (X-X) of the fluid inlet port (211) and the fluid outlet port (212), and there is a side wall (21) that faces the first flat surface (213) axially and is inclined longitudinally with respect to the common axis (X-X), and there the fluid inlet port (211) opens into the valve body cavity (20). A gate valve (1;1';1'') according to any one of the preceding claims, having an inner surface including a second flat surface (214) opening into a cavity (20), wherein in the assembled state of the valve, the seal seat (31) abuts against the first flat surface (213), and the closing member holder (34) abuts against the second flat surface (214) by correspondingly longitudinally inclined flat contact surfaces (3412) in the valve closed position.

6. The gate valve (1; 1') according to any one of the preceding claims, wherein the stem (6) is an extension stem, the valve body (2) is provided with a valve body extension (4) that defines a valve internal chamber (40) together with the valve body (2) and defines the top entry opening (50), and the support component (32) of the seal seat (31) is provided with a support component extension (8) having a first longitudinal end (81) that is detachably connected to the support component (32) of the seal seat (31) and a second longitudinal end (82) that is located near or in the top entry opening (50).

7. The gate valve (1; 1') according to claim 6, wherein the second longitudinal end (82) longitudinally abuts against the removable bonnet (5) or is connected to a removable upper member (820) of the valve, the upper member (820) is located in the top entry opening (50) and longitudinally abuts against the bonnet (5) directly or indirectly.

8. The gate valve (1; 1') according to claim 6 or 7, wherein the support structure extension (8) is a tubular member surrounding the extension stem (6).

9. The gate valve (1; 1') according to claim 8, further comprising a bellows seal (9) disposed around the extension stem (6) in an annular hollow space (80) defined between the tubular member and the extension stem (6).

10. The gate valve (1; 1') according to claim 9, further comprising a seal plate (820) that seals the tubular member at the second longitudinal end (82), wherein the longitudinal end of the bellows seal (9) is fixed to one side surface of the seal plate (820).

11. The gate valve (1) according to any one of claims 6 to 10, further comprising an insulating assembly (7) detachably housed in the internal chamber (40) and configured to thermally separate a first region of the internal chamber (40) adjacent to the valve body (2) from a second region of the internal chamber (40) adjacent to the top entry opening (50).

12. The gate valve (1) according to claim 11, wherein the closing member assembly (3), the support structure extension (8) of the support structure portion (32) of the seal seat (31), the extension stem (6), and the heat insulating assembly (7) form a removable unit (10) that can be inserted integrally into and removed integrally from the internal chamber (40) through the top entry opening (50).

13. A gate valve (1) according to any one of the preceding claims, further comprising a jacket (12) that surrounds the valve body (2), if present, the valve body extension (4), and preferably forms a hollow space (120) that is evacuated.

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