Gate valve with removable cartridge

Abstract

A gate valve (1) comprises a valve body (2) delimiting a valve body cavity (20) accessible through a valve top entry opening (50); a removable bonnet (5) closing said top entry opening (50); a sealing seat (31) arranged in the valve body cavity (20); a gate closure member (33) hold by a closure member holder (34) and linearly movable relative to the valve body (2) and the sealing seat (31), and a stem (6) comprising a first end connected to said closure member holder (34) and a second end protruding through the removable bonnet (5) and connected to valve actuation means (11). In such a valve, the seal seat (31) is associated to a respective support element (32) removably received in the valve body cavity (20), the support element (32) of the sealing seat (31) defines a seat (320) which receives the gate closure member (33) and the closure member holder (34) in a valve closed position, and the gate closure member (33), the closure member holder (34), the sealing seat (31), and the support element (32) of the sealing seat (31) form a removable closure member assembly (3) that can be inserted / extracted in one piece into / from the valve body cavity (20) through the top entry opening (50) by acting on the support element (32) of the sealing seat (31).

Description

[0001] GATE VALVE WITH REMOVABLE CARTRIDGE

[0002] DESCRIPTION

[0003] TECHNICAL FIELD

[0004] The present invention falls generally within the technical field of gate valves. In particular, the invention relates to a gate valve comprising a valve body which can be accessed through a top entry opening, wherein both the gate closure member and the respective sealing seat can be inserted / extracted into / from the valve body through the top entry opening. The gate valve of the invention can be conveniently made as a valve having an extended configuration and has a preferred, although not exclusive, use for cryogenic applications.

[0005] BACKROUND ART

[0006] Gate valves are well known and nowadays widely used, particularly as shutoff valves, in both civil and industrial fields, because of their advantageous fluid-dynamic performance (in particular, very low pressure drop when the valve is open and possibility of high flow rates), as well as a relatively simple and compact structure.

[0007] In several industrial applications, there is a need for valves that can also be serviced in an inline installed condition. To this end, valves have been developed having a top entry configuration, in which the closure member and the respective seal seat(s) can be inserted / extracted into / from the valve body through a valve top entry opening. Such a configuration allows the valve body interior and the valve components most subject to wear, as indeed the closure member and sealing seat(s), to be accessed for servicing or replacement without the need to remove the valve from the respective line.

[0008] In particular, gate valves having a top entry configuration are known in which, besides the gate closure member, also the sealing seat(s) is / are removably received in the valve body cavity. In this case, to work on these components, first the bonnet that closes the valve top entry opening has to be removed. At the same time with or after the removal of the bonnet, the valve stem is removed together with the gate closure member, which is normally supported by a closure member holder removably connected to an end of the stem itself. At this point, the valve body cavity can be freely accessed and the sealing seat(s) removed. The valve can be reassembled through the same steps described above performed in a reverse sequence.

[0009] Although the steps described above can be carried out even when the valve is installed in a line, it has been found that the need to directly access the valve body cavity for removing and subsequently repositioning the sealing seat(s), combined with the fact that the sealing seat(s) and the closure member have to be extracted / inserted from / into the valve body cavity separately, i.e., in two different steps, can in practice make servicing operations rather complicated and time-consuming. This is apparent in particular, but not only, in valves having an extended configuration, in which operations to be performed inside the valve body cavity are more difficult due to a greater distance between the top entry opening and the valve body cavity itself.

[0010] SUMMARY OF THE INVENTION

[0011] In view of the above, it is a main object of the present invention to provide a gate valve with a top entry opening, in which both the gate closure member and the respective sealing seat can be inserted / extracted into / from the valve body through said top entry opening, and which can be serviced, even in an in-line installed condition, more easily and quickly than known gate valves of the same type.

[0012] More specifically, it is an object of the invention provide a gate valve of the above-mentioned type whose structure allows simplifying and reducing operations to be performed inside the valve body for servicing.

[0013] A further object of the invention is to provide a gate valve with the above-mentioned features that also has a structure as simple as possible and can be manufactured at competitive cost. According to the invention, these objects are achieved by a gate valve having the features set forth in claim 1.

[0014] In particular, the invention relates to a gate valve comprising: a valve body having a lateral wall and a bottom wall, wherein the lateral wall is provided with a fluid inlet port and fluid outlet port having a common axis, and wherein the lateral wall and the bottom wall delimit a valve body cavity which can be accessed through a valve top entry opening; a removable bonnet closing said top entry opening; a sealing seat arranged in the valve body cavity; a gate closure member hold by a closure member holder and linearly movable relative to the valve body and the sealing seat in a plane perpendicular to the common axis of said fluid inlet port and said fluid outlet port between a valve open position, in which the gate closure member allows a fluid flow through the valve body, and a valve close position, in which the gate closure member sealingly engages the sealing seat and prevents a fluid flow through the valve body, and a stem comprising a first end connected to said closure member holder and a second end protruding through the removable bonnet and connected to valve actuation means. The sealing seat is associated to a respective support element removably received in the valve body cavity and defining a seat that receives the gate closure member and the closure member holder in said valve close position, so that the gate closure member, the closure member holder, the sealing seat, and the support element of the sealing seat form a removable closure member assembly which can be inserted / extracted in one piece into / from the valve body cavity through said top entry opening by acting on the support element of the sealing seat.

[0015] Within the framework of the present description and subsequent claims, the following definitions apply:

[0016] - by “longitudinal direction” or “longitudinally” it is meant a direction parallel to the axis of the valve stem;

[0017] - by “axial direction” or “axially” it is meant a direction parallel to the common axis of the inlet port and outlet port of the valve body, and

[0018] - by “transverse direction” or “transversely” it is meant a direction perpendicular to the longitudinal direction and the axial direction.

[0019] These definitions apply to both the valve in the assembled condition and, unless otherwise specified, its components considered in isolation and in an arrangement corresponding to that assumed when they are installed in the valve.

[0020] By providing a special support element for the sealing seat, which is configured to function also as a receiving seat for the gate closure member and the closure member holder, a removable component assembly - referred to herein as “closure member assembly” - comprising the gate closure member and the sealing seat is created in the gate valve of the invention, wherein such an assembly forms a cartridge that can be inserted / extracted into / from the valve body cavity in one piece through the top entry opening of the valve by directly or indirectly acting on, i.e., taking hold of, the support element of the sealing seat.

[0021] Advantageously, in the gate valve of the invention the sealing seat and the gate closure member can thus be inserted / extracted into / from the valve body cavity together, by a single operation. Servicing of the gate valve of the invention is therefore simplified and expedited, especially, but not only, in cases where it is difficult to access the valve body cavity and / or to operate inside the valve body cavity, as it may happen when servicing has to be done on the valve installed in a line and / or when the valve has an extended configuration.

[0022] Moreover, as it shall become more apparent also from the description of preferred embodiments of the invention, the above-mentioned features can be implemented through relatively simple design solutions that can be easily scaled to different valve sizes, which positively affects also manufacturing costs. Preferably, the support element of the sealing seat is directly or indirectly removably connected to the removable bonnet, or directly or indirectly longitudinally abuts against the removable bonnet.

[0023] Advantageously, it is thus possible to counter in an effectively and constructively simple way a possible dragging of the sealing seat support element when the gate closure member is actuated, particularly to open the valve, and thus to stably and securely keep the correct positioning of the sealing seat support element, and, therefore, of the sealing seat itself, in the valve body cavity.

[0024] Preferably, the support element of the sealing seat comprises a lateral wall with flat faces and a bottom wall which at least partially delimit said seat, and an opening opposite to the bottom wall, through which the gate closure member and the closure member holder can be inserted / extracted into / from said seat, wherein the lateral wall comprises a main face provided with an opening intended to receive, preferably removably, the sealing seat and coaxial with said fluid inlet port and said fluid outlet port, and two mutually parallel flanks which extend perpendicularly to said main face from transversely opposing edges thereof.

[0025] Preferably, the support element of the sealing seat comprises guide means intended to cooperate with mating guide means of the closure member holder for guiding the movement of the gate closure member between the valve open position and the valve close position.

[0026] Preferably, the lateral wall of the valve body has an inner side, i.e., a side facing the valve body cavity, comprising a first flat surface at which the fluid outlet port opens into the valve body cavity, said first flat surface being perpendicular to the common axis of the fluid inlet port and the fluid outlet port of the valve body, and a second flat surface, axially opposing the first flat surface, at which said fluid inlet opening opens into the valve body cavity, said second flat surface being longitudinally inclined relative to said common axis. In a valve assembled condition, the sealing seat abuts against said first flat surface, and the closure member holder, in the valve close position, abuts against said second flat surface by means of a respective flat abutment surface, which is correspondingly longitudinally inclined.

[0027] The above-defined first and second flat surfaces of the valve body lateral wall give the valve body cavity, when viewed in a longitudinal section, a generically wedge-shaped configuration, which is matched by a similar configuration of the closure member holder. Such a wedge-shaped configuration advantageously ensures proper positioning of the closure member assembly, particularly of the sealing seat, in the valve body cavity, and makes the centering of the closure member assembly easier upon insertion into the valve body cavity.

[0028] According to a preferred embodiment, which is advantageous in case of valves intended for cryogenic applications or for buried installation, the gate valve of the invention may have an extended configuration, wherein the valve stem is an extended stem and the valve body is provided with a valve body extension delimiting, together with the valve body, a valve inner chamber and defining said a top entry opening.

[0029] Preferably, in this case the support element of the sealing seat is also provided with a support element extension having a first longitudinal end removably connected to the support element of the sealing seat and a second longitudinal end located close to or at said top entry opening. Advantageously, the support element extension allows the closure member assembly to be inserted / extracted by acting only at the top entry opening of the valve even in case of an extended configuration.

[0030] More preferably, the second longitudinal end of the support element extension longitudinally abuts against the removable bonnet or is connected to a valve removable top member, wherein said top member is located at said top entry opening and directly or indirectly longitudinally abuts against the removable bonnet.

[0031] Preferably, the support element extension consists of a tubular member surrounding the extended stem.

[0032] In this case, the gate valve of the invention may further comprise a bellow seal arranged around the extended stem in an annular hollow space defined between the tubular member and the extended stem. Such a seal may be advantageous in applications involving special and / or hazardous fluids, such as, for example, cryogenic applications, as a further sealing system, additional to the seals normally provided in the valve removable bonnet, to prevent fluid leakage towards the outside through the through openings for the stem.

[0033] If such a bellow seal is present, the gate valve of the invention preferably also comprises a sealing plate that sealingly closes said tubular member at the second longitudinal end thereof, and the bellow seal preferably has a longitudinal end attached to a side of the sealing plate. The sealing plate may in this case form said removable top member of the valve.

[0034] In case of an extended configuration, and particularly for cryogenic applications, the gate valve of the invention may conveniently also comprise a thermal insulation assembly removably received in the valve inner chamber and configured so as to thermally separate a first region of said inner chamber adjacent to the valve body from a second region of said inner chamber adjacent to the top entry opening.

[0035] This advantageously allows limiting heat transfer, particularly convective heat transfer, within the valve inner chamber between the valve body and the closure member assembly, which under operating conditions are at cryogenic temperatures, and the valve upper portion, with the valve bonnet and valve actuation means, which under operating conditions may instead be at higher temperatures, typically at room temperature.

[0036] Preferably, the closure member assembly, the support element extension of the support element of the sealing seat, the extended stem, and the thermal insulation assembly form a removable unit which can be inserted / extracted in one piece into / from the valve inner chamber of the valve through the top entry opening.

[0037] Advantageously, all removable valve assemblies and components can therefore be inserted / extracted together and simultaneously into / from the valve inner chamber. Even if a thermal insulation assembly is present, servicing operations on the valve involving components of the closure member assembly can thus be carried out particularly easily and quickly, as described above.

[0038] Still for cryogenic applications, the gate valve of the invention may advantageously comprise an outer jacket enclosing the valve body and, if present, the valve body extension, forming a preferably evacuated hollow space thereabout.

[0039] BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Further features and advantages of the invention shall become more evident from the following detailed description of preferred embodiments thereof, made hereafter, for indicating and non-limiting purposes, with reference to the accompanying drawings, in which:

[0041] - Fig. 1 is a schematic longitudinal sectional view of a preferred embodiment of a gate valve according to the invention;

[0042] - Fig. 2 is an enlarged view of a detail in Fig. 1 at the valve body;

[0043] - Fig. 3 is a cross-sectional view of the detail in Fig. 2, at a section plane passing through the longitudinal center axis Y-Y of the valve;

[0044] - Fig. 4 is a view similar to the view in Fig. 2, in a valve open configuration;

[0045] - Fig. 5 is a schematic lateral view of the closure member assembly of the valve in Fig. 1;

[0046] - Fig. 6 is a schematic cross-sectional view of the closure member assembly in Fig. 5, at section line VI- VI in Fig. 5;

[0047] - Fig. 7 is a schematic longitudinal sectional view of the closure member assembly in Fig. 5, at section line VII- VII in Fig. 6;

[0048] - Fig. 8 is a view similar to the view in Fig. 7, partially exploded;

[0049] - Fig. 9 is a schematic longitudinal sectional view of the valve in Fig. 1, without the bonnet and the actuation means;

[0050] - Fig. 10 is a schematic longitudinal sectional and partially exploded perspective view of the valve in Fig. 1, without the bonnet and the actuation means; - Fig. 11 is a schematic perspective view of a removable unit of the valve in Fig. 1;

[0051] - Fig. 12 is a schematic partially exploded perspective view of the removable unit in Fig. 11;

[0052] - Fig. 13 is a schematic longitudinal sectional view of another preferred embodiment of a gate valve according to the invention, and

[0053] - Fig. 14 is a schematic longitudinal sectional view of a further preferred embodiment of a gate valve according to the invention.

[0054] DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0055] Figs. 1-12 show a first preferred embodiment of a gate valve according to the invention, generally indicated by reference numeral 1. The valve 1 has an extended configuration and is especially intended for cryogenic applications, wherein in this framework by “cryogenic applications”, applications are meant which involve operating temperatures equal to or lower than -150°C (123 K).

[0056] The valve 1 comprises a valve body 2 having a valve body extension 4. The valve body extension 4 is arranged above to the valve body 2 and delimits therewith an inner chamber 40 of the valve 1. The interior of the inner chamber 40 and the valve body 2 can be accessed through a top entry opening 50 of the valve 1, which is defined at a free end of the valve body extension 4, longitudinally opposite to 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 valve removable bonnet 5.

[0057] The valve body 2 is preferably made in one piece and comprises a lateral wall 21 and a bottom wall 22 delimiting a valve body cavity 20.

[0058] A fluid inlet port 211 and a fluid outlet port 212 having a common axis X-X are formed in the lateral wall 21 of valve body 2. A mounting fitting 23 is associated to each of the ports 211, 212 for mounting the valve 1 in a line (not shown). By way of example, the mounting fittings 23 are configured here as fittings for a weld-joint mounting, however they could be configured for any other kind of mounting, in particular also releasable, known to the person skilled in the art.

[0059] The lateral wall 21 has a preferably cylindrical outer side. Therefore, the valve body extension 4 preferably consists of a cylindrical wall extending longitudinally above the valve body 2 and having a diameter equal to the outer diameter of lateral wall 21.

[0060] As best seen in Figs. 2, 4, and 10, the lateral wall 21 further has an inner side, facing the valve body cavity 20, comprising a first flat surface 213 at which the fluid outlet port 212 opens into the valve body cavity 20, and a second flat surface 214, axially opposing the first flat surface 213, at which the fluid inlet port 211 opens into the valve body cavity 20. The first flat surface 213 is arranged perpendicular to the axis X-X, while the second flat surface 214 is longitudinally inclined relative to the axis X-X, so that the valve body cavity 20, when viewed in a longitudinal section, is generally wedge-shaped. More specifically, the second flat surface

[0061] 214 forms an angle a (see Fig. 4) preferably of between 9° and 15°, for example equal to 12°, with a transverse plane perpendicular to the axis X-X.

[0062] As it can be seen in Fig. 1 and, in greater detail, in Figs. 2-4, a sealing seat 31 intended to be sealingly engaged by a gate closure member 33 of the valve 1 is arranged in the valve body cavity 20. The sealing seat 31 is associated to a respective support element 32 removably received in the valve body cavity 20, whereas the gate closure member 33 is hold by a closure member holder 34, through which the gate closure member 33 is connected to a stem 6 of the valve 1.

[0063] The gate closure member 33 is linearly movable in longitudinal direction, i.e., vertically, in a plane perpendicular to the axis X-X, relative to the support element 32 of sealing seat 31, and thus relative to sealing seat 31 itself and the valve body 2, between a valve open position (shown in Figs. 1-3 and 9), in which the gate closure member 33 allows a fluid flow through valve body 2, and a valve close position (shown in Fig. 4), in which the gate closure member 33 sealingly engages the sealing seat 31 and prevents a fluid flow through valve body 2.

[0064] A particular aspect of the valve 1 lies in that the support element 32 of the sealing seat 31 is configured so as to form a seat 320 that receives the gate closure member 33 and the closure member holder 34 in the valve close position, and in that the support element 32, the sealing seat 31, the gate closure member 33, and the closure member holder 34 form a closure member assembly, generally indicated in the figures by reference numeral 3, which can be inserted / extracted in one piece into / from the valve body cavity 2 through the top entry opening 50, by acting on the support element 32, as better described hereinafter with reference to Figs. 9-12. In the assembled condition, the closure member assembly 3 thus forms a removable cartridge of the valve 1, which comprises the main inner components thereof that may require servicing or replacement, namely, the sealing seat 31 and the gate closure member 33. The sealing seat 31 and gate closure member 33 can be inserted / extracted into / from the valve body cavity 20 by a single operation and servicing of valve 1 is thus simplified and expedited.

[0065] As it can be seen in greater detail in Figs. 5-8, the support element 32 of the sealing seat 31 is preferably made in one piece and comprises a flat-faced lateral wall and a bottom wall 322 at least partially delimiting the seat 320 that receives like a pocket the gate closure member 33 and the closure member holder 34. These elements can be inserted / extracted into / from the seat 320 through an opening 323 opposite to the bottom wall 322. The opening 323 is peripherally surrounded by a respective flange 3231.

[0066] The lateral wall comprises a main face 3211 provided with an opening 3212 intended to removably receive the sealing seat 31, and two mutually parallel flanks 3213 extending perpendicular to the main face 3211 from transversely opposite edges thereof. In a position axially opposite to the main face 3211, the lateral wall has a cutout 3214, which exposes a rear side of the closure member holder 34 when the latter is received together with the gate closure member 33 in the seat 320. When the support element 32 is received in the valve cavity 20, the main face 3211 of its lateral wall faces the first flat surface 213 of the lateral wall 21 of the valve body 2, and the sealing seat 31, fitted in said opening 3212, sealingly abuts against said first flat surface 213. The opening 3212 and, therefore, the sealing seat 31 are arranged coaxially to axis X-X.

[0067] The sealing seat 31 is received in the opening 3212 in an axially fixed condition and is retained therein by suitable retaining means 35, such as an elastic retaining ring.

[0068] The sealing seat 31 is configured as an annular body having two axially opposed sealing faces 311, 312. Specifically, the sealing face 311 facing toward the inside of the seat 320 defined by the support element 32 is intended to be sealingly engaged by the gate closure member 33, while the sealing face 312 facing toward the outside of the seat 320 is intended to sealingly engage the valve body 2. The sealing face 312 is provided with a sealing ring 3121, while the sealing face 311 may have no sealing ring if, as in the example shown here, the gate closure member 33 has one. In this case, the sealing occurs directly on the surface of the sealing face 311, possibly coated with a layer of a suitable high-hardness material.

[0069] The gate closure member 33 is configured as a flat disc comprising a sealing face 331 intended to sealingly engage the sealing seat 31 and provided with a sealing ring 3311 to this end. The face opposite to the sealing face 331 is provided with a connecting shank 332, through which the gate closure member 33 can be removably connected to the closure member holder 34.

[0070] The closure member holder 34 consists of a generically disc-shaped body, preferably made in one piece, comprising a first side, or front side, 341, a second side, or rear side, 342 axially opposing the first side, and a perimeter edge 343 axially connecting the first and second sides 341, 342. As already mentioned above, when the closure member holder 34 is fully received in the seat 320 defined by the support element 32 of the sealing seat 31 (valve closed position), the rear side 342 of the closure member holder 34 is located at the cutout 3214 and is thus freely exposed to the outside of the seat 320. The front side 341 is substantially flat and comprises a circular receiving recess 3411 for the gate closure member 33. The receiving recess 3411 has a diameter substantially equal the diameter of the gate closure member 33 and a depth smaller than the thickness of the gate closure member 33, so that when the gate closure member 33 is received in the receiving recess 3411, its sealing face 331 protrudes from the surface of the closure member holder 34. At the center of the receiving recess 3411 the closure member holder 34 has an axial through- hole 344, into which the connecting shank 332 of the gate closure member 33 fits. The connecting shank 332 can be secured to the closure member holder 34 by suitable removable fastening means 36, such as for example a nut, fitted to the end of the connecting shank 332 protruding from the rear side 342 of the closure member holder 34.

[0071] At least in a longitudinally lower portion thereof, the rear side 342 of the closure member holder 34 comprises a flat surface 3421 which is longitudinally inclined relative to the axial direction. In the assembled condition of the valve 1 and in the closed position of the valve, the flat surface 3421 abuts against the above-described inclined flat surface 214 of the valve body cavity 20. In greater detail, the flat surface 3421 forms with a transverse plane an angle equal to the inclination angle a of the flat surface 214 of valve body cavity 20 (see Fig. 8). Therefore, at least in a longitudinally lower portion thereof, the closure member holder 34, when viewed in a longitudinal section, also has a wedge-like shape, corresponding to the wedge-like shape of the valve body cavity 20.

[0072] In order to precisely and safely guide the movement of the gate closure member 33 relative to the seat 320 defined by the support element 32 of the sealing seat 31, the closure member holder 33 is preferably provided, at its perimeter edge 343, with a pair of transversely opposite, parallel guide grooves 3431 (visible in Fig. 6). The guide grooves 3431 are intended to slidably receive a corresponding pair of guide protrusions 3215 (visible in Figs. 6-8) having a mating shape and formed at the inner side of the flanks 3213of the lateral wall of the support element 32 of the sealing seat 31.

[0073] At the perimeter edge 343, the closure member holder 34 is also provided with an engagement seat 3432 for the stem 6.

[0074] The stem 6 of the valve 1 is an extended stem, having a total length preferably of between 350 mm and 2500 mm. In any case, the stem 6 has a total length greater than the sum of the maximum extension in the longitudinal direction (heights) of the valve body 2, the valve body extension 4, and the bonnet 5, so as to protrude out of the inner chamber 40 of the valve 1 through the bonnet 5.

[0075] The stem 6 is preferably made in one solid piece, but it is also possible to make the stem 6 in more pieces, either solid or hollow. In any case, the stem 6 comprises a first end intended to be connected to the closure member holder 34, in particular configured to engage removably, but integrally relative to translations along the longitudinal direction, the engagement seat 3432 of the closure member holder 34, and a second end intended to be connected to actuation means 11 of the valve 1 and for this purpose protruding out of the valve 1 through the bonnet 5.

[0076] The actuation means 11 may be manual actuation means, as in the examples shown here, or motorized actuation means, and are in any case known to the person skilled in the art.

[0077] The removable bonnet 5 may have any suitable configuration known to the person skilled in the art and shall not be described in greater detail herein, as it is not relevant to the invention.

[0078] As apparent from Fig. 1, in the valve 1, and generally in gate valves according to the invention having an extended configuration, the support element 32 of the sealing seat 31 is conveniently provided with a support element extension 8 having a first longitudinal end 81 removably connected to the support element 32 and a second longitudinal end 82 located close to or at the top entry opening 50. In the assembled condition of the valve 1, the second longitudinal end 82 longitudinally abuts, directly or indirectly, against the bonnet 5. By using a support element extension 8, even in case of an extended configuration the closure member assembly 3 can be inserted / extracted by operating at the valve top entry opening 50, without the need to reach the valve body cavity 20. Moreover, in the assembled condition of the valve 1, the support element extension 8 helps to counter a possible dragging of the support element 32 when the gate closure member 33 is actuated, and thus to stably keep the support element 32, and the sealing seat 31 therewith, in the correct position within the valve body cavity 20.

[0079] In the embodiment shown herein, the support element extension 8 consists of a preferably cylindrical tubular member, that coaxially surrounds the stem 6 forming an annular hollow space 80 thereabout.

[0080] The first longitudinal end 81 of the tubular member 8 is provided with a respective flange 811 (best seen in Figs. 11 and 12), which is intended to be removably connected to the flange 3231 at the opening 323 of the support element 32 by means of threaded fastening means, particularly here screws 14. The second longitudinal end 82 of the tubular member 8 is provided with a respective flange 821 and is closed by a sealing plate 820. The sealing plate 820 has centrally a through-hole through which the stem 6 protrudes. In the assembled condition of the valve 1, the sealing plate 820 sealingly engages peripherally the flange 51 of the valve top entry opening 50 and directly abuts, at its upper side, against the bonnet 5. The sealing plate 820 is attached, for example welded, to the second longitudinal end 82, at the flange 821 thereof.

[0081] In the annular hollow space 80 there is preferably a bellow seal 9 surrounding the stem 6. The bellow seal comprises a longitudinal end attached, e.g., welded, to the underside of the sealing plate 820 and a second end attached, e.g., welded, to a ring 91 integral in translation with the stem 6.

[0082] The valve 1 also comprises a thermal insulation assembly 7 removably received in the inner chamber 40, between the valve body 2 and the top entry opening 50. The thermal insulation assembly 7 aids to thermally separate a first region of the inner chamber 40 adjacent to the valve body 2, which under operating conditions is at cryogenic temperature, from a second region of the inner chamber 40 adjacent to the top entry opening 50 and the bonnet 5, which under operating conditions may instead be at higher temperatures, such as room temperature. In particular, the thermal insulation assembly 7 is configured to substantially limit conductive and convective heat transfer that may arise in the inner chamber 40 due to the temperature difference between the two regions mentioned above.

[0083] The thermal insulation assembly 7 has overall a cylindrical annular configuration and concentrically surrounds and is integral with the support element extension 8 described above. More specifically, the thermal insulation assembly 7 comprises a containment chamber 71 having a cylindrical annular shape and arranged coaxially to the support element extension 8. The containment chamber 71 is filled with a solid thermally insulating material 72, for example, vetronite G10-FR4. The thermally insulating material 72 preferably forms a solid body, made in one piece or several pieces.

[0084] In the transverse direction, i.e., laterally, the containment chamber 71 is delimited internally by the tubular member 8 and externally by a cylindrical wall 712. In the longitudinal direction, i.e., at the top and bottom, the containment chamber 71 is delimited respectively by the flange 821 of tubular member 8 and by a flat annular wall 713 parallel to the flange 821.

[0085] The tubular member 8, the cylindrical wall 712, and the annular wall 713 are rigidly connected to each other, e.g., by welding, and form together a rigid support and containment structure for the thermally insulating material 72.

[0086] The cylindrical wall 712 preferably has an outer diameter only slightly smaller than the inner diameter of the valve body extension 4 delimiting the inner chamber 40. In view of these minimal transverse clearances, the cross-sectional area of the free volume of the inner chamber 40 can be considered to be substantially completely taken up by the thermal insulation assembly 7.

[0087] The thermal insulation assembly 7 preferably has a length of between 0.65-L and 0.85-L, where L is the total length of the inner chamber 40, i.e., of the valve body extension 4, of the valve 1.

[0088] It is apparent from the above that the closure member assembly 3, the support element extension 8, the sealing plate 820, the bellow seal 9, the thermal insulation assembly 7, and the stem 6, form a removable unit 10, also shown separately in Figs. 10 and 11, which can be inserted / extracted in one piece into / from the inner chamber 40 of the valve 1 , by acting on the sealing plate 820, at the valve top entry opening 50.

[0089] To this end, the sealing plate 820 is preferably provided with fixed or removable attachment means to facilitate gripping and handling of the removable unit 10, manually or by lifting machinery. In the embodiment shown herein, for example, the sealing plate includes at its upper side a pair of threaded blind holes 8201, shown in Figs. 1 and 9 and for the sake of clarity omitted in Figs. 10-12, to which eyebolts 13 can be temporarily screwed (see Fig. 9).

[0090] The above-described inner structure of the valve 1 allows, even in case of an extended configuration and when a thermal insulation assembly 7 is present, the closure member assembly 3 to be extracted / inserted for servicing or replacement operations particularly easily and quickly, by acting only at the valve top entry opening 50, i.e., without the need to directly reach the valve body cavity 20.

[0091] The valve 1 may conveniently comprise a jacket 12 surrounding the valve body 2, the valve body extension 4, and possibly also a section of the mounting fittings 23, forming around these elements a hollow space 120 which can be evacuated. At the top entry opening 50, the hollow space 120 is closed by the flange 51 forming the support and fastening base for the bonnet 5. The jacket 12 can be omitted when the valve 1 is intended to operate in environments that are per se thermally insulated, such as in so-called “cold boxes”.

[0092] Referring in particular to Figs. 9-12, by way of example the steps for extracting the removable unit 10, and therefore the closure member assembly 3, from the valve 1 shall now be described in greater detail.

[0093] In a first step, the bonnet 5 is removed, so as to clear the valve top entry opening 50 and expose the upper side of the sealing plate 820.

[0094] In a subsequent step, eyebolts 13 are screwed into the threaded blind holes 8201 (Fig. 9).

[0095] In a further subsequent step, the removable unit 10 formed by the closure member assembly 3, the support element extension 8, the sealing plate 820, the bellow seal 9, the thermal insulation assembly 7, and the stem 6, is extracted, manually or with the aid of suitable lifting machines and by using the eyebolts 13, from the valve inner chamber 40 (Fig. 10).

[0096] Once the removable unit 10 has been extracted from the valve 1, it can be disassembled. In particular, it is now possible to separate the support element 32 of the sealing seat 31 from the removable unit 10 by removing the screws 14 connecting the flange 3231 of the support element 32 to the flange 821 of the support element extension 8 (Fig. 12). Once the support element 32 has been removed, the closure member holder 34 can be freely accessed to disengage it from the stem 6 and thus separate this element too from the removable unit 10.

[0097] At this point, it is possible to freely work on the support element 32 of the sealing seat 31 and one the closure member holder 34, on site or in a factory, for inspecting, servicing, or replacing the sealing seat 32 and / or the gate closure member 33.

[0098] For reassembling the removable unit 10 and inserting it again into the valve 1 the same steps described above are performed in a reverse sequence.

[0099] Fig. 13 shows another preferred embodiment of a gate valve according to the invention, generally indicated by reference numeral 1’. Elements being the same as or functionally equivalent to those of the embodiment in Figs. 1-12, in particular the valve body 2 and the closure member assembly 3, are indicated by the same reference numerals and shall not be described herein any further.

[0100] The valve 1’ still has an extended configuration, but lacks a thermal insulation assembly arranged in the inner chamber 40, a jacket surrounding the valve body 2 and the valve body extension 40, and a bellow seal surrounding the stem 6. The valve 1’ is suitable for general applications requiring an extended configuration, such as applications involving buried installation.

[0101] As in the embodiment described above, also in the valve 1’ the support element 32 of the sealing seat 31 has a support element extension 8, consisting of a preferably cylindrical tubular member, which coaxially surrounds the stem 6 thereby forming an annular hollow space 80 around it, wherein a first longitudinal end 81, provided with a flange 811, of the support element extension 8 is removably connected to the support element 32 itself, and a second longitudinal end 82, provided with a flange 821, of the support element extension 8 is located at the valve top entry opening 50.

[0102] In this case, however, the support element extension 8 has such a length that, in the assembled condition of the valve 1’, its longitudinal end 82 directly longitudinally abuts against the bonnet 5, because a sealing plate is not required to close the longitudinal end 82 itself. The threaded blind, or possibly in this case also through, holes 8201 for attaching the eyebolts 13 are formed in the flange 821 of the longitudinal end 82.

[0103] In the valve 1’ the closure member assembly 3, the support element extension 8 of the support element 32 of the sealing seat 31, and the stem 6 form a removable unit 10’ which can be inserted / extracted in one piece into / from the inner chamber 40 of valve 1’, by acting on the longitudinal end 82 of the support element extension 8, at the valve top entry opening 50.

[0104] The removable unit 10’, and thus the closure member assembly 3, can be extracted / inserted from / into the valve 1 ’ as well as disassembled and reassembled following the same steps as described for the valve 1.

[0105] Fig. 14 shows a further preferred embodiment of a gate valve according to the invention, generally indicated by reference numeral 1”. Elements being the same as or functionally equivalent to those of the embodiment in Figs. 1-12, in particular the valve body 2 and the closure member assembly 3, are indicated by the same reference numbers and shall not be described herein any further.

[0106] The 1” valve has a standard, i.e., not extended, configuration. Specifically, the valve 1” comprises a standard stem 6”, wherein by “standard stem” it is meant herein a stem having a length of less than 350 mm, and lacks both a valve body extension for the valve body 2 and a support element extension for the support element 32 of the sealing seat 31.

[0107] The interior of valve body 2 can be accessed through a top entry opening 50” delimited by the valve body 2 itself and closed by a removable bonnet 5 of the valve 1”.

[0108] In this case, the support element 32 of the sealing seat 31 is removably connected to the bonnet 5. In greater detail, the connection flange 3231 that peripherally surrounds the opening 323 of the support element 32 is bolted to a pair of pins 15” longitudinally protruding from the underside of the bonnet 5. This connection allows, on the one hand, countering possible dragging in the longitudinal direction of the support element 32 when the gate valve 33 is actuated, and, on the other hand, making the support element 32, and thus the closure member assembly 3, integral with bonnet 5, so that the extraction / insertion of the closure member assembly 3 from / into the valve body 2 can be carried out jointly with the removal / installation of the bonnet 5 from / onto the valve body 2.

[0109] By way of example, for removing the closure member assembly 3 from the valve 1” it is enough to remove the bonnet 5 together with the stem 6”. After the removable unit formed by the bonnet 5, the closure member assembly 3, and the stem 6” has been separated from the valve body 2, it can be disassembled. In particular, it is now possible to remove the support element 32 of the sealing seat 31 from the bonnet 5 by releasing the bolted connections which connect the flange 3231 of the support element 32 to the pins 15” of the bonnet 5. Once the support element 32 has been removed, the closure member holder 34 can be freely accessed to disengage it from the stem 6” and remove it from the removable unit 10. At this point, it is possible to freely work on the support element 32 of the sealing seat 31 and the closure member holder 34, on site or in a factory, for inspecting, servicing, or replacing the sealing seat 32 and / or the gate closure member 33.

[0110] For reassembling the removable unit formed by the bonnet 3, the closure member assembly 3, and the stem 6” and inserting it again into the valve 1” the same steps described above are performed in a reverse sequence.

[0111] As an alternative to a removable connection between the support element 32 of the sealing seat 31 and the bonnet 5 as described above, it could be envisaged also in valve 1” that the support element 32 only abuts, directly or indirectly, against the bonnet 5, according to design solutions, for example, similar to those implemented in the embodiments of the valve of the invention described above.

[0112] It is apparent from the above that the present invention provides a gate valve with a top entry opening that can be serviced particularly easily and quickly, even in an in-line installed condition and / or in case of a valve extended configuration. These features are achieved with a particularly simple structure, thanks to a special configuration and mutual arrangement of the valve inner components that allow a closure member assembly or cartridge to be formed which comprises both the sealing seat and the gate closure member and can be inserted / extracted in one piece into / from the valve, through the top entry opening.

Claims

CLAIMS1. Gate valve (1; 1’; 1”), comprising: a valve body (2) having a lateral wall (21) and a bottom wall (22), wherein the lateral wall (21) is provided with a fluid inlet port (211) and fluid outlet port (212) having a common axis (X-X), and wherein the lateral wall (21) and the bottom wall (22) delimit a valve body cavity (20) which can be accessed through a valve top entry opening (50; 50”); a removable bonnet (5) closing said top entry opening (50; 50’); a sealing seat (31) arranged in the valve body cavity (20); a gate closure member (33) hold by a closure member holder (34) and linearly movable relative to the valve body (2) and the sealing seat (31) in a plane perpendicular to the common axis (X-X) of said fluid inlet port (211) and said fluid outlet port (212) between a valve open position, in which the gate closure member (33) allows a fluid flow through the valve body (2), and a valve close position, in which the gate closure member (33) sealingly engages the sealing seat (31) and prevents a fluid flow through the valve body (2), and a stem (6; 6”) comprising a first end connected to said closure member holder (34) and a second end protruding through the removable bonnet (5) and connected to valve actuation means (11), wherein the sealing seat (31) is associated to a respective support element (32) removably received in the valve body cavity (20), wherein the support element (32) of the sealing seat (31) defines a seat (320) which receives the gate closure member (33) and the closure member holder (34) in said valve close position, and wherein the gate closure member (33), the closure member holder (34), the sealing seat (31), and the support element (32) of the sealing seat (31) form a removable closure member assembly (3) which can be inserted / extracted in one piece into / from the valve body cavity (20) through said top entry opening (50; 50”) by acting on the support element (32) of the sealing seat (31).

2. Gate valve (1; 1’; 1”) according to claim 1, wherein the support element (32) of the sealing seat (31) is directly or indirectly removably connected to the removable bonnet (5), or directly or indirectly longitudinally abuts against said bonnet (5).

3. Gate valve (1; 1’; 1”) according to any one of the previous claims, wherein the support element (32) of the sealing seat (31) comprises a lateral wall (3211, 3213) with flatfaces and a bottom wall (322) which at least partially delimit said seat (320), and an opening (323) opposite to the bottom wall (322), through which the gate closure member (33) and the closure member holder (34) can be inserted / extracted into / from said seat (320), and wherein the lateral wall (3211, 3213) comprises a main face (3211) provided with an opening (3212) intended to receive the sealing seat (31) and coaxial with said fluid inlet port (211) and said fluid outlet port (212), and two mutually parallel flanks (3213) which extend perpendicularly to said main face (3211) from transversely opposing edges thereof.

4. Gate valve (1; 1’; 1”) according to any one of the previous claims, wherein the support element (32) of the sealing seat (31) comprises guide means (3215) intended to cooperate with mating guide means (3431) of the closure member holder (34) for guiding the movement of the gate closure member (33) between said valve open position and said valve close position.

5. Gate valve (1; 1’; 1”) according to any one of the previous claims, wherein the lateral wall (21) of the valve body (2) has an inner side comprising a first flat surface (213) at which said fluid outlet port (212) opens into the valve body cavity (20), said first flat surface (213) being perpendicular to the common axis (X-X) of said fluid inlet port (211) and said fluid outlet port (212), and a second flat surface (214), axially opposing the first flat surface (213), at which said fluid inlet opening (211) opens into the valve body cavity (20), said second flat surface (214) being longitudinally inclined relative to said common axis (X-X), and wherein, in a valve assembled condition, the sealing seat (31) abuts against said first flat surface (213), and the closure member holder (34), in the valve close position, abuts against said second flat surface (214) by means of a respective flat abutment surface (3412), which is correspondingly longitudinally inclined.

6. Gate valve (1; 1’) according to any one of the previous claims, wherein said stem (6) is an extended stem, the valve body (2) is provided with a valve body extension (4) delimiting, together with the valve body (2), a valve inner chamber (40) and defining said top entry opening (50), and the support element (32) of the sealing seat (31) is provided with a support element extension (8) having a first longitudinal end (81) removably connected to the support element (32) of the sealing seat (31) and a second longitudinal end (82) located close to or at said top entry opening (50).

7. Gate valve (1; 1’) according to claim 6, wherein said second longitudinal end (82) longitudinally abuts against the removable bonnet (5) or is connected to a valveremovable top member (820), wherein said top member (820) is located at said top entry opening (50) and directly or indirectly longitudinally abuts against said bonnet (5).

8. Gate valve (1; 1’) according to claim 6 or 7, wherein the support element extension (8) is a tubular member surrounding the extended stem (6).

9. Gate valve (1; 1’) according to claim 8, further comprising a bellow seal (9) arranged around the extended stem (6) in an annular hollow space (80) defined between the tubular member and the extended stem (6).

10. Gate valve (1; 1’) according to claim 9, further comprising a sealing plate (820) which sealingly closes the tubular member at said second longitudinal end (82), wherein a longitudinal end of the bellow seal (9) is fixed to a side of said sealing plate (820).

11. Gate valve (1) according to any one of claims 6 to 10, further comprising a thermal insulation assembly (7) removably received in said inner chamber (40) and configured so as to thermally separate a first region of said inner chamber (40) adjacent to the valve body (2) from a second region of said inner chamber (40) adjacent to said top entry opening (50).

12. Gate valve (1) according to claim 11, wherein the closure member assembly (3), the support element extension (8) of the support element (32) of the sealing seat (31), the extended stem (6), and the thermal insulation assembly (7) form a removable unit (10) which can be inserted / extracted in one piece into / from said inner chamber (40) through said top entry opening (50).

13. Gate valve (1) according to any one of the previous claims, further comprising a jacket (12) enclosing the valve body (2) and, if present, the valve body extension (4), forming a preferably evacuated hollow space (120) thereabout.

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