WO2019215548A1

WO2019215548A1 - Fitting element and connection kit

Info

Publication number: WO2019215548A1
Application number: PCT/IB2019/053593
Authority: WO
Inventors: Angelo Bugatti
Original assignee: Valvosanitaria Bugatti S.P.A.
Priority date: 2018-05-08
Filing date: 2019-05-02
Publication date: 2019-11-14
Also published as: AU2019202182A1; IT201800005168A1

Abstract

A fitting element (20) for the connection of a first tubular fitting conduit to a second tubular fitting conduit comprises a tubular body (20'), releasable connection means (220) for a releasable connection to the second tubular fitting conduit, and a first end (204) telescopically couplable with a fluid-tight seal within the first tubular fitting conduit. The fitting element (20) is provided, around said first end, with a threaded nut (206) suitable to screw onto an externally threaded portion of the first fitting conduit. The threaded nut is free to move axially relative to said first end between two limit positions.

Description

" FI TTING ELEMENT AND CONNECTION KI T"

DESCRIPTION

[0001] The present invention generally concerns a fitting element for connecting a first fitting conduit and a second fitting conduit together.

[0002] In particular, the fitting element according to the invention is suitable to connect a fluid distribution system, such as water or gas, to a fluid treatment device, such as a boiler.

[0003] In some applications, for example in the residential heating sector, maintenance or replacement operations of the fluid treatment device, for example a residential boiler, may be problematic due to the difficulty in carrying out the operation of disconnecting the water or gas system from the treatment device, due to the substantially fixed positioning of both the system and the fluid treatment device.

[0004] Thus, such maintenance or replacement operations require long intervention times and demanding maneuvers, also because of the often very small spaces wherein maintenance technicians find themselves operating.

[0005] The object of the present invention is to propose a fitting element between two fitting conduits that facilitates the disconnection of such fitting conduits and in particular allows a fitting conduit of a supply or distribution system of a fluid to be quickly and easily disconnected from a fitting conduit of a treatment device of the fluid, such as a boiler.

[0006] Said object is achieved with a fitting element according to claim 1. The dependent claims describe preferred embodiments of the invention.

[0007] According to claim 1, a fitting element is proposed for the connection of a first tubular fitting conduit to a second tubular fitting conduit.

[0008] The fitting element consists of a tubular body of a fitting element that extends between a first connecting end on the first tubular fitting conduit and a second connecting end on the second tubular fitting conduit. The second end has releasable connection means for a releasable connection to the second tubular fitting conduit .

[0009] The first end is telescopically couplable with a fluid-tight seal inside the first tubular fitting conduit .

[0010] The fitting element is provided, around the first end, with a threaded nut suitable to screw onto an externally threaded portion of the first fitting conduit.

[0011] The threaded nut is free to move axially relative to the first end between two limit positions.

[0012] The threaded nut has an internally threaded distal portion, a proximal portion for coupling to the fitting element's tubular body, and, between said distal portion and proximal portion, an intermediate annular portion having a diameter greater than the diameter of the distal portion and an axial extension sufficient to form, with the fitting element body, an annular gap suitable to receive the externally threaded portion of the first fitting conduit.

[0013] In one embodiment, in the proximal portion of the threaded nut, an annular groove is made, which houses a retaining element, there being made in the fitting element body a depressed annular portion engaged by the retaining element, with possibility of axial movement.

[0014] In one embodiment, on the first end of the fitting element body at least one annular sealing element is fitted, suitable to form a fluid-tight seal with the inner surface of the first tubular fitting conduit.

[0015] In one embodiment, the retaining element is an elastic ring.

[0016] In particular, the elastic ring is mounted with clearance around the depressed portion and is compressed when inserted in the respective annular groove of the threaded nut.

[0017] In one embodiment, the depressed annular portion is axially delimited by two shoulders which act as limit stops for the axial movement of the fitting element body with respect to the threaded nut.

[0018] A further object of the present invention is a kit for connecting a gas supply conduit to a boiler, where the boiler is equipped with a gas inlet conduit defining the second fitting conduit. The kit comprises a fitting element as defined above and a gas flow shut-off valve.

[0019] The fluid shut-off valve comprises a valve body that defines a gas inlet conduit, a gas outlet conduit in fluidic communication with the inlet conduit, and, between said inlet conduit and outlet conduit, a shutter seat wherein is housed a shutter to shut off the passage of the fluid.

[0020] The gas outlet conduit has an externally threaded end portion and is preceded axially by a rearward annular portion with a substantially smooth outer surface, where the outer diameter of such rearward annular portion is equal to or less than the smallest diameter of the threaded end portion, wherein the distal portion of the threaded nut is suitable to screw onto the externally threaded end portion, and wherein the intermediate annular portion of the threaded nut forms, with the fitting element body, an annular gap suitable to receive said externally threaded end portion when the distal portion has completely surpassed the threading of said end portion and encircles the rearward annular portion, in such a way that the nut is free to rotate idly around the gas outlet conduit.

[0021] A further object of the present invention is a kit for connecting a water supply conduit to a boiler, where the boiler is equipped with a water inlet conduit defining the second fitting conduit.

[0022] The kit comprises a fitting element as defined above and a shut-off valve of the water flow, wherein the shut- off valve comprises a valve body defining a water inlet conduit, a water outlet conduit in fluidic communication with the inlet conduit, and, between said inlet conduit and outlet conduit, a shutter seat wherein is housed a shutter to shut off the passage of the water flow.

[0023] The water outlet conduit has an externally threaded end portion and is preceded axially by a rearward annular portion with a substantially smooth outer surface, where the outer diameter of said rearward annular portion is equal to or less than the smallest diameter of said threaded end portion, wherein the distal portion of the threaded nut is suitable to screw onto the externally threaded end portion, and wherein the intermediate annular portion of the threaded nut forms, with the fitting element body, an annular gap suitable to receive the externally threaded end portion when the distal portion has completely surpassed the threading of the end portion and encircles the rearward annular portion, in such a way that the nut is free to rotate idly around the water outlet conduit.

[0024] A further object of the present invention is a kit for connecting a hot water distribution system to a hot water outlet conduit from a boiler, comprising a fitting element as defined above and a distribution system connection. The distribution system connection comprises an inlet conduit connectible to the fitting element and system connection means suitable to obtain a releasable sealed connection with a tube of the hot water distribution system.

[0025] The inlet conduit has an externally threaded end portion and is preceded axially by a rearward annular portion with a substantially smooth outer surface, where the outer diameter of said rearward annular portion is equal to or less than the smallest diameter of said threaded end portion, wherein the distal portion of the threaded nut is suitable to screw onto the externally threaded end portion, and wherein the intermediate annular portion of the threaded nut forms, with the fitting element body, an annular gap suitable to receive said externally threaded end portion when the distal portion has completely surpassed the threading of said end portion and encircles the rearward annular portion, in such a way that the nut is free to rotate idly around the inlet conduit.

[0026] The features and advantages of the fitting element and the kits for connecting water or gas tubes to a boiler inlet conduit and a hot water outlet conduit from the boiler to a conduit of a hot water distribution system, according to the invention, will in any case be evident from the description below of their preferred examples of embodiment, given by way of non-limiting example, with reference to the accompanying figures, wherein :

- figure 1 is a perspective view of the fitting element according to the invention;

figure 2 is an axial cross-section of the fitting element ;

figures 3 and 3a are two views of the side of the fitting element, in a maximum extension configuration and in a minimum extension configuration, respectively;

- figure 4 is a perspective view in separate parts of a connection kit, through a fluid shut-off valve, of a first conduit, for example a water supply conduit, to a second conduit, for example a water inlet conduit of a boiler, in a first embodiment;

figure 4a is a perspective view of the assembled kit; figure 4b is a perspective view, in axial cross- section, of the kit of figure 4a;

- figures 5 and 5a show, in partial axial cross-section, the kit of the previous figures in a minimum extension configuration and in a maximum extension configuration, respectively;

figures 6, 6a and 6b show, in perspective view in separate parts, assembled and in an axial cross-section, the connection kit in a second embodiment;

figures 7, 7a and 7b show, in perspective view in separate parts, assembled and in axial cross-section, the connection kit in a third embodiment;

figures 8, 8a and 8b show, in perspective view in separate parts, assembled and in an axial cross-section, the connection kit in a fourth embodiment;

figures 9, 9a and 9b show, in perspective view in separate parts, assembled and in axial cross-section, the connection kit in a fifth embodiment;

- figures 10, 10a and 10b show, in perspective view in separate parts, assembled and in an axial cross-section, the connection kit in a sixth embodiment;

- figure 11 is a perspective view in separate parts of a fitting connection kit of a first conduit, for example for a hot water distribution system, to a second conduit, for example a hot water outlet conduit of a boiler, in a first embodiment;

- figure 11a is a perspective view of the kit of figure 11 assembled;

figure lib is a perspective view, in axial cross- section, of the kit of figure 11a;

- figures 12, 12a and 12b show, in perspective view in separate parts, assembled and in an axial cross-section, the fitting connection kit in a second embodiment;

- figures 13, 13a and 13b show, in perspective view with separate parts, assembled and in axial cross-section, the fitting connection kit in a third embodiment;

- figures 14, 14a and 14b show, in perspective view in separate parts, assembled and in an axial cross-section, the fitting connection kit in a fourth embodiment;

- figures 15, 15a and 15b show, in perspective view with separate parts, assembled and in axial cross-section, the fitting connection kit in a fifth embodiment; and

- figures 16, 16a and 16b show, in perspective view in separate parts, assembled and in an axial cross-section, the fitting connection kit in a sixth embodiment;

[0027] Figures 1-3 show a fitting element 20 for the connection of a first tubular fitting conduit to a second tubular fitting conduit.

[0028] The fitting element 20 comprises a fitting element tubular body 20' that extends between a first end 204, or proximal end, connecting to the first tubular fitting conduit and a second end 205, or distal end, connecting to the second tubular fitting conduit.

[0029] The second end 205 is equipped with releasable connection means 202 for a releasable connection to the second tubular fitting conduit.

[0030] The first end 204 is telescopically couplable with a fluid-tight seal inside the first tubular fitting conduit .

[0031] The fitting element is provided, around the first end 204, with a threaded nut 206 suitable to screw onto an externally threaded portion of the first fitting conduit .

[0032] The threaded nut 206 is free to move axially relative to the first end 204 of the body 20 between two limit positions, as shown in figures 3 and 3a.

[0033] The threaded nut 206 has a distal portion 206a, threaded internally, a proximal portion 206b to couple to the fitting element tubular body 20, and, between such distal portion and proximal portion, an intermediate annular portion 206c with a larger diameter than the diameter of the distal portion 206a.

[0034] Moreover, this intermediate portion 206c has sufficient axial extension to form, with the body of the fitting element 20, in particular with its first end 204, an annular gap 207 suitable to receive, as will be better described hereinafter, the externally threaded portion of the first fitting conduit.

[0035] In one embodiment, an annular groove 210 is obtained in the proximal portion 206b of the threaded nut 206, which houses a retaining element 212. In the body of the fitting element 20 there is a depressed annular portion 214 engaged, with the possibility of axial movement, by the retaining element 212.

[0036] For example, the retaining element 212 is an elastic ring .

[0037] In one embodiment, on the first end 204 of the fitting element body 20 at least one annular sealing element 208 is fitted, suitable to form a fluid-tight seal with the inner surface of the first tubular fitting conduit .

[0038] In one embodiment, the elastic ring forming the retaining element 212 is mounted with clearance around the depressed portion 214 and is compressed when inserted into the respective annular groove 210 of the threaded nut .

[0039] In one embodiment, the depressed annular portion 214 is axially delimited by two shoulders 214', 214" which act as limit stops for the axial movement of the fitting element body 20 relative to the threaded nut 206. [0040] In one embodiment, the second releasable connection means 202 comprise a rotating nut 220 engaged, with the possibility of rotation, on the distal end of the fitting element body 20' and having an internal thread 222 for screwing it to a threaded end of the second fitting conduit .

[0041] For example, the rotating nut 220 has a radial tooth 224 facing inwards so as to be engaged axially by a radial counter-tooth 226 extending outwards from the distal end of the fitting element body 20' .

[0042] Figures 4-10 show some embodiments of a fluid shut off valve connection kit, indicated collectively at 1, of a first conduit 2, for example of water or gas supply, to a second conduit 4, for example, a water or gas inlet conduit of a boiler, in some embodiments that use the fitting element 20 described above.

[0043] In the following description, elements common to the various embodiments of the invention are indicated with the same reference numbers.

[0044] The connection kit 1 comprises a fluid shut-off valve 10 and a fitting element 20.

[0045] According to an embodiment illustrated in the figures, the shut-off valve 10 is suitable to be directly connected to a water or gas supply conduit, shown in the drawings with a tube end section 2, while the fitting element 20 connects the shut-off valve to the treatment device, shown in the drawings with a first section of a water or gas inlet tube 4 of the fluid treatment device.

[0046] However, it is obvious that the shut-off valve 10 could be connected directly to the fluid treatment device, while the fitting element 20 could be interposed between the shut-off valve 10 and the water or gas supply tube .

[0047] The fluid shut-off valve 10 comprises a valve body 102 that defines a first fluid passage conduit 104, a second fluid passage conduit 106, in fluid communication with the first conduit 104, and a shutter seat 108 between said first and second fluid passage conduits.

[0048] In one embodiment, the first conduit 104 and the second conduit 106 are coaxial with each other and develop around a main valve axis X.

[0049] The first conduit 104 is equipped with the first releasable connection means 110 suitable for the connection with a tube 2 of the distribution system.

[0050] In one embodiment shown in figures 4-4b, the first conduit 104 is suitable to make a threaded connection to the tube end section 2. For example, the first conduit 104 has an internally threaded end section 104' suitable for screwing onto an externally threaded end section 2 of the tube end section 2. [0051] In a variant embodiment shown in figures 6-6b, the first conduit 104 is suitable to make a connection by deformation of the tube end section 2.

[0052] In particular, the first conduit 104 has a tapered end 104" suitable to cause a deformation due to enlargement of the end of the tube end section 2. The first conduit 104 also has an external thread 104a whereon is screwed a deformation nut 104b with a conical internal portion suitable for compressing the tube end 2 against the tapered end 104" of the first conduit 104.

[0053] In another embodiment illustrated in figures 7-7b, the deformation of the tube end section 2 is obtained by means of an ogive-shaped deformation element 105 which, when pressed against the end of the first conduit 104 by screwing an ogive nut 105' on an external thread 104a of the first conduit 104, radially deforms the tube 2 preventing it from slipping off of the first conduit 104.

[0054] In another embodiment illustrated in figures 8-8b, the deformation of the tube end section 2 is obtained by means of a cone deformation element 107 which, when pressed against the end of the first conduit 104 by screwing a deformation nut 107' on an external thread 104a of the first conduit 104, radially deforms the tube

2, preventing it from slipping off of the first conduit

104. [0055] In another embodiment illustrated in figures 9-9b, the tube end section 2 is inserted fully into the first conduit 104, with the interposition of one, preferably two, O-ring seals 109. In this case, the tube 2 is deformed radially to prevent it from being extracted from the first conduit 104 by acting directly on the outer wall of the first conduit 104 by means of a special deformation tool.

[0056] In another embodiment shown in figures 10-10b, the tube end section 2 is inserted into the first conduit 104 by means of a pressure quick-coupling system, indicated collectively at 111.

[0057] In all the example embodiments described above, the shutter seat 108 houses a shutter 110 to shut off the fluid passage (see, for example, figure 4b) .

[0058] In one embodiment, the shutter 110 is a spherical shutter wherein an axial passage 120 is obtained. The shutter 110 is rotatable between an open valve position, wherein such axial passage 120 puts the first conduit 104 in communication with the second conduit 106, and a closed valve position, wherein the axial passage 120 is substantially orthogonal to the first and second conduits and wherein the shutter, in cooperation with sealing elements 114 with the shutter seat 108, prevents the passage of fluid from the first conduit to the second conduit, or vice versa.

[0059] For its rotation, the spherical shutter is connected to a shaft 114 rotatable by means of a user-operated control lever 116.

[0060] In some embodiments, in particular in the case of kits to connect to the inlet conduit for the water in the boiler, a flow control valve 118, such as a one-way valve, is housed in the axial passage 120.

[0061] In effect, the water valves may be equipped internally with a flow-limiting valve, or with a "check valve" in particular to achieve the non-return effect.

[0062] As shown in the drawings, such one-way valve or flow-limiting valve is easily removable from the shut-off valve, provided that the shutter is in the closed position, even when the shut-off valve is installed.

[0063] According to one aspect of the invention, the fitting element 20 has a distal end, i.e. facing the opposite side relative to the shut-off valve 10, equipped with second releasable connection means 202 suitable for connection to an inlet tube 4 of the fluid treatment device .

[0064] The fitting element 20 also has a proximal end portion 204 telescopically coupled and fluid-tight inside the second passage conduit 106 of the fluid. "Telescopic coupling" means that the proximal end portion 204 of the fitting element 20 may be inserted with the possibility of axial movement, i.e. with variable insertion depth, into the second conduit 106. Due to this telescopic coupling, it is therefore possible to vary the distance between the second releasable coupling means 202 and the end of the second conduit 106.

[0065] In particular, the fitting element 20 may be axially moved between an advanced position, wherein the proximal end portion 204 is completely extracted from the second conduit 106, and a rearward position, wherein the proximal end portion 204 is completely inserted into the second conduit 106. This is highlighted in particular in figures 5 and 5a.

[0066] For anchoring to the valve body 102, the fitting element 20 is equipped with a connecting element 206 which engages the second conduit 106. The proximal end 204 is free to move axially and relative to such connecting element 206.

[0067] In one embodiment, the fitting element 20 comprises a fitting element body 20' extending around a body axis Y (figure 2) . When the fitting element 20 is connected to the valve body 102, the main valve body axis X and the extension axis Y are coaxial with each other.

[0068] In one embodiment, on the proximal end portion 204 of the fitting element 20, at least one annular sealing element 208 is fitted, suitable to provide a fluid-tight seal with the inner surface of the second passage conduit 106 of the fluid.

[0069] In one embodiment, the valve body 102 comprises a threaded end portion 106' around the second passage conduit 106 of the fluid.

[0070] Such threaded end portion 106' is preceded by a rearward annular portion 106a having an outer diameter equal to or less than the minimum diameter, or core diameter, of the threaded end portion. "Minimum diameter", or "core diameter", means the diameter of the cylinder tangent to the internal apexes, or bases, of the threading .

[0071] The connecting element 206 is in the form of a threaded nut suitable for screwing onto such threaded end portion 106' .

[0072] More specifically, the connecting element 206 comprises a valve body annular connecting portion 206a suitable for engaging an end portion of the valve body which encircles the second fluid passage conduit 106, for example the threaded end portion 106' , and an extension body annular connecting portion 206b.

[0073] In one embodiment, in this extension body annular connecting portion 206b, an annular groove 210 is obtained that houses a retaining element 212. In the extension body 20' an intermediate depressed annular portion 214 is obtained, engaged, with the possibility of axial movement, by such retaining element 212.

[0074] In one embodiment, the retaining element 212 is an elastic ring.

[0075] In particular, this retaining element 212 in the form of an elastic ring is mounted with clearance around the depressed intermediate portion 214 and is placed in compression when inserted into the respective annular groove 210 of the connecting element 206.

[0076] In this context, the elasticity of the elastic ring is mainly expressed in the circumferential direction. For example, the retaining element 212 consists of a circular section ring made of a metallic or polymeric material, wherein an interruption is obtained which imparts the required elasticity.

[0077] In other words, when, during the assembly of the fitting element 20, the connecting element 206 is fitted on the body 20' , in the depressed portion 214 of which the retaining element 212 has been previously positioned, the latter is initially compressed by the connecting element 206, for example by means of one of its conical ends 206b', and then snaps into the annular groove 210. Since the retaining element housed in the annular groove 210 may not escape from the depressed portion 214, the connecting element 206 remains attached to the body 20' , allowing the latter to move relative to the connecting element 206 in a measure corresponding to the axial extension of the depressed portion 214.

[0078] In this respect, the depressed annular section 214 is delimited axially by two shoulders 214', 214" which serve as limit stops for the axial movement of the fitting element body 20' relative to the connecting element 206 (and thus also relative to the valve body 102 when the connecting element 206 has been made integral with the valve body 102) .

[0079] According to one aspect of the invention, the connecting element 206 comprises a valve body annular connecting portion 206a having an internal thread 206a' (Figure 2) suitable to be screwed onto the externally threaded end portion 106' of the valve body, and, between such valve body annular connecting portion 206a and the extension body annular connecting portion 206b, an intermediate annular portion 206c having a larger diameter than the diameter of the valve body annular connecting portion 206a and an axial extension at least equal to the axial extension of the externally threaded end portion 106' .

[0080] In other words, it is possible to screw the connecting element 206 to the externally threaded end portion 106' until the complete disengagement between the two threads: in this situation the externally threaded end portion 106' is encircled, without interference, by the intermediate annular portion 206c of the connecting element 206.

[0081] In effect, this intermediate portion 206c forms, with the body of the fitting element, an annular cavity wherein the externally threaded end portion 106' may be housed .

[0082] In this way, and due to the diameter of the rearward annular portion 106a which allows such rearward annular portion not to interfere with the distal threaded portion of the nut, the nut 206 is free to rotate idly around the valve body.

[0083] This embodiment contributes to improving the safety of the shut-off device. In effect, due to the idle rotation of the connecting element 206, it is not possible for the fitting element 20 to be unscrewed inadvertently from the valve body 102, e.g. when cleaning the components. On the contrary, to remove the fitting element 20 from the shut-off valve 10, it is necessary to act willfully to engage the thread 206a' of the connecting element 206 with the thread 106' of the end section of the valve body.

[0084] In one embodiment, the second releasable connection means 202 comprise a rotating nut 220 engaged, with the possibility of rotation, on the distal end of the fitting element body 20' and having an internal thread 222 for screwing it to a threaded end 4 of the tube 4. For example, the rotating nut 220 has a radial tooth 224 facing inwards so as to be engaged axially by a radial counter-tooth 226 extending outwards from the distal end of the fitting element body 20' .

[0085] A further object of the present invention is a fitting connection kit, indicated collectively at 300 in figures 11-16, for the connection of a hot water distribution system, in the drawings represented by an end section of system tube 302, to a hot water outlet conduit from a boiler, in the drawings represented by an end section of boiler tube 304.

[0086] The kit 300 comprises the fitting element 20 described above, either independently or when combined with the fluid shut-off valve 10, and a distribution system fitting 310.

[0087] The distribution system fitting 310 comprises an inlet conduit 3106 connectible to the fitting element 20 and system connection means 3108 suitable for obtaining a releasable sealed connection with a tube 302 of the hot water distribution system.

[0088] The inlet conduit 3106 has an externally threaded end portion 3106' and is axially preceded by a rearward annular portion 3106a with a substantially smooth external surface. The outer diameter of this rearward annular portion 3106a is equal to or less than the smaller diameter, as defined above, of the threaded end portion 3106' .

[0089] The coupling between the fitting element 20 and the inlet conduit 3106 of the system fitting 310 is exactly the same as the one described above for the fluid shut- off valve 10 and thus does not need any further description. In effect, the inlet conduit 3106 of the fitting 310 corresponds to the outlet conduit 106 of the fluid shut-off valve 10.

[0090] In an embodiment shown in figures 11-llb, the system connecting means 3108 comprise a threaded fitting whereon one threaded end of the end tube portion 302 is screwed.

[0091] In a variant embodiment shown in figures 12-12b, the system connection means 3108 are suitable to make a connection by deformation of the tube end section 302.

[0092] In particular, the system fitting 310 has a tapered end 3104" suitable to cause a deformation due to enlargement of the end of the tube end section 302. The fitting 310 has moreover an external thread 3104a whereon is screwed a deformation nut 3104b with a conical internal portion suitable for compressing the tube end 2 against the tapered end 104" of the first conduit 104.

[0093] In another embodiment illustrated in figures 13-13b, the deformation of the tube end section 302 is obtained by means of an ogive-shaped deformation element 3105 which, when pressed against the corresponding end of the system fitting 310 by screwing an ogive nut 105' on an external thread 3104a of the fitting end 310, radially deforms the tube 302, preventing it from slipping off the fitting .

[0094] In another embodiment illustrated in figures 14-14b, the tube end section 302 is inserted fully into a tubular end portion 3104 of the fitting 310, with the interposition of one, preferably two, O-ring seals 3109. In this case, the tube 302 is deformed radially to prevent it from being extracted from the fitting by acting directly on the outer wall of the tubular end portion 3104 of the first conduit 104 by means of a special deformation tube.

[0095] In another embodiment shown in figures 15-15b, the tube end section 302 is inserted into the corresponding fitting end 310 by means of a pressure quick-coupling system, indicated collectively at 3111.

[0096] In another embodiment illustrated in figures 16-16b, the deformation of the tube end section 302 is obtained by means of a cone-shaped deformation element 3107 which, when pressed against the corresponding end of the fitting 310 by screwing a deformation nut 3107' on an external thread 3104a of the fitting end 310, radially deforms the tube 302 preventing it from slipping off the fitting 310.

[0097] From the description provided above of the fitting element and the connection kits according to the invention, it is evident how they allow the intended purposes to be achieved.

[0098] In effect, starting with a situation wherein the connection kit is connected, on the one hand, to a water or gas supply or distribution tube, and, on the other, to the fluid treatment device, such as a boiler, to disconnect the fluid treatment device, the second releasable connection devices 202 are first disconnected from the tube 4, for example by completely unscrewing the rotating nut 220.

[0099] At this point, the fitting element 20 need only be pushed towards the shut-off valve 10, or towards the fitting 310, causing the insertion of the proximal portion 204 into the second conduit 106 of the valve or in the inlet conduit of the fitting 3106. Due to simple and quick operation, a free space is created between the distal end of the fitting element 20 and the tube end 4, which allows easy removal of the fluid treatment device.

[00100] To connect the connection kit to the distribution or supply system and to the treatment device, the telescopic coupling between the fitting element 20 and the valve body 10 or the fitting 310 is used in the same way, but in the opposite direction.

[00101] To the embodiments of the fitting element and of the connection kit according to the invention, one skilled in the art may, to satisfy contingent needs, make modifications, adaptations and substitutions of some elements with others that are functionally equivalent, without departing from the scope of the following claims. Each of the features described as belonging to a possible embodiment may be implemented independently from the other described embodiments.

Claims

1. Fitting element for connecting a first tubular fitting conduit to a second tubular fitting conduit, comprising a tubular body of the fitting element extending between a first connecting end on the first tubular fitting conduit and a second connecting end on the second tubular fitting conduit, wherein said second end is provided with releasable connecting means for a releasable connection to the second tubular fitting conduit, and wherein:

- the first end is telescopically couplable with a fluid-tight seal inside said first tubular fitting conduit ;

- the fitting element is provided, around said first end, with a threaded nut suitable to screw onto an externally threaded portion of the first fitting conduit;

- the threaded nut is free to move axially relative to said first end between two limit positions;

- the threaded nut has an internally threaded distal portion, a proximal portion coupling to the tubular body of the fitting element, and, between said distal portion and proximal portion, an intermediate annular portion having a diameter greater than the diameter of the distal portion and an axial extension sufficient to form, with the body of the fitting element, an annular gap suitable to receive the threading of said externally threaded portion .

2. Fitting element according to claim 1, wherein, in the proximal portion of the threaded nut, an annular groove is made, which houses a retaining element, in the body of the fitting element there being made a depressed annular portion engaged by said retaining element, with possibility of axial movement.

3. Fitting element according to claim 2, wherein on the first end of the fitting element body at least one annular sealing element is fitted suitable to form a fluid-tight seal with the inner surface of the first tubular fitting conduit.

4. Fitting element according to claim 2 or 3, wherein said retaining element is an elastic ring.

5. Fitting element according to the preceding claim, wherein said elastic ring is mounted with clearance around the depressed portion and is placed in compression when inserted in the respective annular groove of the threaded nut.

6. Fitting element according to any one of claims 2-5, wherein said depressed annular portion is axially delimited by two shoulders which act as limit stops for the axial movement of the fitting element body with respect to the threaded nut.

7. Kit for connecting a gas supply conduit to a boiler, where the boiler is provided with a gas inlet conduit defining the second fitting conduit, the kit comprising a fitting element according to any one of the preceding claims and a gas flow shut-off valve, wherein the fluid shut-off valve comprises a valve body defining a gas inlet conduit, a gas outlet conduit in fluidic communication with the inlet conduit, and, between said inlet conduit and said outlet conduit, a shutter seat wherein is housed a shutter to shut off the passage of the fluid,

wherein the gas outlet conduit has an externally threaded end portion and is preceded axially by a rearward annular portion with a substantially smooth outer surface, where the outer diameter of said rearward annular portion is equal to or less than the smallest diameter of said threaded end portion, wherein the distal portion of the threaded nut is suitable to screw onto the externally threaded end portion, and wherein the intermediate annular portion of the threaded nut forms, with the fitting element body, an annular gap suitable to receive said externally threaded end portion when the distal portion has completely surpassed the threading of said end portion and encircles the rearward annular portion, in such a way that the nut is free to rotate idly around the gas outlet conduit.

8. Kit for connecting a water supply conduit to a boiler, where the boiler is provided with a water inlet conduit defining the second fitting conduit, the kit comprising a fitting element according to any one of claims 1-6 and a shut-off valve of the water flow, wherein the shut-off valve comprises a valve body defining a water inlet conduit, a water outlet conduit in fluidic communication with the inlet conduit, and, between said inlet conduit and outlet conduit, a shutter seat wherein is housed a shutter to shut off the passage of the water flow,

wherein the water outlet conduit has an externally threaded end portion and is preceded axially by a rearward annular portion with a substantially smooth outer surface, where the outer diameter of said rearward annular portion is equal to or less than the smallest diameter of said threaded end portion, wherein the distal portion of the threaded nut is suitable to screw onto the externally threaded end portion, and wherein the intermediate annular portion of the threaded nut forms, with the fitting element body, an annular gap suitable to receive said externally threaded end portion when the distal portion has completely surpassed the threading of said end portion and encircles the rearward annular portion, in such a way that the nut is free to rotate idly around the water outlet conduit.

9. Kit according to the preceding claim wherein the shutter element houses a flow regulating valve.

10. Kit for connecting a hot water distribution system to a hot water outlet conduit from a boiler, comprising a fitting element according to any one of claims 1-6 and a distribution system connection, wherein said distribution system connection comprises an inlet conduit connectable to the fitting element and system connection means suitable to provide a releasable sealed connection with a tube of the hot water distribution system,

wherein said inlet conduit has an externally threaded end portion and is preceded axially by a rearward annular portion with a substantially smooth outer surface, where the outer diameter of said rearward annular portion is equal to or less than the smallest diameter of said threaded end portion, wherein the distal portion of the threaded nut is suitable to screw onto the externally threaded end portion, and wherein the intermediate annular portion of the threaded nut forms, with the fitting element body, an annular gap suitable to receive said externally threaded end portion when the distal portion has completely surpassed the threading of said end portion and encircles the rearward annular portion, so that the nut is free to rotate idly around the inlet conduit .