TECHNICAL FIELD

The present description relates to a flange, in particular to a flange which can be used in a disc of a valve. The present disclosure also relates to a disc and a valve comprising such a flange, in particular a throttle triple offset valve or TOV (Triple Offset Valve).

FRAMEWORK OF THE DESCRIPTION

Known flanges are used to secure a sealing ring to a sealing ring of a disc body of a throttle valve by means of screws that tighten this sealing ring between the flange and the disc body, thus forming the disc of the valve.

However, one of the major problems encountered with valves with these flanges is the possibility that the screws loosen and, even worse, unscrew with consequent losses inside the pipe in which the valve is inserted, as the fixing system between the sealing ring and valve body is compromised. These losses can cause serious damages to other components present in systems which valves of this type are used.

The state of the art includes solutions aimed at preventing the screws from loosening or unscrewing, such as glues or paints, lock washers, washers with safety nose and self- locking nuts. These solutions, however, are not used in the valves described above when they are used with particular fluids or in extreme conditions of temperature or pressure, or yet because they are difficult to be used for reasons of encumbrance. Another solution used in order to prevent the screws from loosening or unscrewing consists in the creation of welding points between the screws and the flange, but also this technique is to be considered unreliable as breakage of the welding points can occur, in addition to the fact that this solution is laborious and difficult, if not impossible, to be implemented during the maintenance of systems located in dangerous environments or without connection to the electricity mains. Still, a further solution of the prior art consists in the realization of a lip near the top of each axial hole present on the flange. This lip is then pressed against the head of the screws after they have been screwed, so this solution too is expensive and laborious to be implemented.

SUMMARY OF THE DESCRIPTION

An objective of the present description is to provide a valve free from these drawbacks. This object is achieved with a flange, a disc and a valve, the main features of which are specified in the appended claims.

Thanks to the guide that at least partially intersects the screw seats, a wire can be inserted easily and quickly into the flange to lock all the screws at the same time, which thus cannot loosen or even unscrew.

Furthermore, this flange does not have any of the aforementioned drawbacks of the known flanges.

The guide preferably comprises a groove, so as to limit the production costs of the flange.

Furthermore, by using screws with a collar, the space for the head of the screws is exploited and thus the flange must not have an increased thickness to accommodate the guide.

Furthermore, the flange can be ideally used in a throttle valve, in particular with triple offset or TOV (Triple Offset Valve).

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages and characteristics of the flange and of the valve according to the present description will be clear to those skilled in the art from the following detailed and non-limiting description of several embodiments making reference to the attached drawings wherein:

- figure 1 shows a rear view of the valve;

- figure 2 shows section II-II of figure 1; - figure 3 shows an exploded view of the disc of the valve of figure 1;

- figure 4 shows a front view of the disc of figure 3 in the case where the wire 13 is of the type with a solid section;

- figure 4a shows a front view of the disc of figure 3 in the case where the wire 13 is of the type with a spring with tangent turns;

- figure 5 shows the section V-V of figure 4;

- figure 5a shows the section V-V of figure 4a;

- figure 5b shows the highlighted detail of figure 5a;

- figure 6 shows section VI- VI of figure 4;

- figure 6a shows section VI- VI of figure 4a;

- figure 7 shows section VII- VII of figure 4 or 4a ;

- figure 8 shows a front view of a screw in the disc of figure 3;

- figure 9 shows a partial section of a second embodiment of the disc;

- figure 10 shows a front view of a screw in the disc of figure 9;

- figure 11 shows a partial section of a third embodiment of the disc;

- figure 12 shows a front view of a screw in the disc of figure 11 ;

- figure 13 shows the section XIII-XIII of figure 6;

- figure 13a shows the section XIII-XIII of figure 6a;

- figure 14 shows the section XIV-XIV of figure 4.

- figure 14a shows the section XIV-XIV of figure 4a.

EXEMPLARY EMBODIMENTS

Referring to figures 1 and 2, it is possible to see that the valve according to the present description comprises at least one valve body 1, a disc 2 and a shaft 3. The valve body further comprises a sealing seat la for the disc 2. The disc 2 is substantially shaped as a disk and can be rotated by the shaft 3 in the valve body 1 so that its relative position with respect to the sealing seat la leads to the opening or closing of the valve. In particular, the disc 2 comprises along its peripheral edge at least one sealing ring 6. When this sealing ring 6 comes into contact with the sealing seat la of the valve body 1, the valve is closed. In this closed position the disc 2 is substantially perpendicular to the flow path. When the disc 2 is placed along the same direction of the flow path, the valve is in the fully open position. Every other position of disc 2 defines a partial opening or closing of the valve. The disc 2 comprises a hub in which the shaft 3 is arranged, which is keyed to the disc 2 thanks to one or more keys 10 and/or to at least one screw 4. The shaft 3 also includes, at an upper end, at least one groove 3a which allows keying the shaft 3 to an organ for the transmission of motion (not shown) by means of a key (not shown). The valve according to the present description is in particular a throttle triple offset valve or TOV (Triple Offset Valve).

Referring also to Figures 3, 4, 5, 6, 13 and 14, one sees that the disc 2 comprises, in addition to the sealing ring 6, at least a disc body 5, a flange 7 and a plurality of screws 8. The flange 7 on its turn comprises a plurality of axial holes the 7g within which are inserted the screws 8 to tighten the sealing ring 6 between the flange 7 and the disc body

5, so that the sealing ring 6 is blocked in the disc 2 and can perform its sealing function.

In particular, the disc body 5 comprises, on its front surface 5a, a first seat 5b arranged around a first internal projection 5g. The first seat 5b on its turn comprises a groove 5c adapted to house a ring seal 11, preferably of the spiro metallic type of stainless steel and graphite. The sealing ring 6, preferably made by superimposing stainless steel and graphite strips, is arranged in the first seat 5b, above the gasket 11, surrounding the first internal projection 5g.

The first internal protrusion 5g on its turn comprises a second seat 5d arranged around a second internal protrusion 5h. In particular, the first seat 5b and/or the second seat 5d are substantially circular, the first internal protrusion 5g and/or the second internal protrusion 5h are substantially cylindrical.

The second seat 5d, in the assembled disc 2, is preferably flush with the sealing ring

6 The second seat 5d is adapted to receive the flange 7 and comprises on its surface a plurality of threaded holes 5e, preferably blind holes. The threaded holes 5e of the disc body 5 are aligned with the axial holes 7g of the flange 7 and can accommodate the threaded stem 8b of the screws 8 which, passing through the axial holes 7g of the flange

7, join the flange 7 to the disc body 5, so as to lock the sealing ring 6 between them. The disc body 5 also comprises a recess 5f which is disposed astride the first seat 5b and the second seat 5d and is adapted to accommodate a pad 12. Even the sealing ring 6 on the inner edge presents a recess 6a adapted to accommodate the pad 12, so that the sealing ring 6 can be mounted in a specific orientation with respect to the disc body 5. The disc body 5 includes on its rear surface, that is the surface opposite to the front surface 5a, also the hub 5i for the shaft 3 and a groove 5j for keys 10.

The flange 7 is an annular body, for example substantially circular, which has a central cavity, at least one front surface 7c and at least one rear surface 7d, which are joined together by at least one internal perimeter surface 7e, for example substantially cylindrical, which delimits the central cavity, and from at least one external perimetral surface 7f, for example substantially cylindrical.

The axial holes the 7g mutually connect the front surface 7c and the rear surface 7d of the flange 7 and are arranged around the central cavity. The axial holes 7g comprise a neck 7h which acts as a stop for the head 8a of a screw 8 and which separates two portions, in particular substantially cylindrical, coaxial but with different diameters: a first portion acting as a seat 7m suitable for receiving the head 8 a of the screw 8 and a second portion, of smaller diameter than the first portion, adapted to receive a portion of the stem 8b of the screw 8. The seat 7m is open towards the front surface 7c of the annular body of the flange 7.

At least a guide 7a, in particular a substantially arc-shaped guide, for example, substantially shaped as an arc of circle, in particular substantially circular, is formed in the annular body of the flange 7 so that this guide 7a intersects at least partially, in particular tangentially, the seats 7m of a plurality of axial holes 7g.

In use, the flange 7 is joined to the disc body 5 by means of screws 8 inserted in the axial holes 7g of the flange 7 and screwed into the blind holes 5e of the disc body 5. Moreover, at least one wire 13 is inserted through an inlet hole 7i in the guide 7a of the flange 7 so that this wire 13 prevents the screws 8 to escape from the respective axial hole 7g, blocking partially the seat 7m of the axial hole 7g. In particular, portions of the wire 13 interfere with the heads 8a of the screws 8 and prevent them to move axially towards the outside of the flange 7.

Preferably, a first end 13a of the wire 13 is fixed to the outer circumferential surface 7f or to the front surface 7c of the flange 7 and the second end 13b is free inside the guide 7a, so that the wire 13 forms an open path to the interior of the guide 7a. The second end 13b of the wire 13 is preferably rounded to facilitate sliding within the guide 7a and the first end 13a is preferably shaped like a hook so that it can be inserted into a cavity 7n placed preferably adjacent to the inlet hole 7i of the flange 7. According to one aspect, the wire 13 is preferably a flexible metal cable, in particular made of stainless steel.

According to one aspect, illustrated in figures 4a, 5a, 6a, 13a and 14a, the wire 13 is of the type with springs with tangent turns. As shown in Figure 14a, the spring wire 13, once inserted, is locked in position by a threaded dowel 13c positioned at the entrance of the radial hole for inserting the wire 13. The dowel 13c is then punched by punching 13d to prevent it from unscrewing.

According to one aspect, shown in figures 5a, 6a and better shown in the detail view of figure 5b, the wire 13 is housed in a seat constituted by the groove 7j obtained on the flange 7 and by a second groove 5k obtained on the internal projection 5h of the disc body 5. This second groove, which in the example of figure 5b is shaped in the form of an arc of a circle, is arranged so as to direct its concavity towards the concavity of the groove 7j in the flange 7, so as to cooperate with it for defining a housing for wire 13. Even if this aspect is illustrated with reference to figure 5a in which the wire 13 is of the type with spring with tangential turns, it can also be replicated in the embodiment of Figure 5 wherein wire 13 it is a flexible metal cable.

The guide 7a preferably comprises at least one groove, for example with a substantially circular or substantially rectangular section, made on a perimeter surface, in particular the internal perimeter surface 7e, which is connected to the inlet hole 7i by a section, in particular substantially tangent to the internal perimeter surface 7e, which crosses the flange 7 and puts the groove in communication with the external perimeter surface 7f and/or the front surface 7c of the flange 7. The wire 13 is therefore arranged in the guide 7a between the flange 7 and the disc body 5, in particular its second internal projection 5h.

Referring also to figures 7 and 8, it can be seen that the screws 8 preferably comprise a collar 8c which is preferably arranged between the head 8a and the stem 8b and is adapted to be arranged between the wire 13 and the flange 7 to prevent the movement of the screws 8. In the first embodiment the head 8a is cylindrical with hexagonal graft. Referring also to figures 9 and 10, it can be seen that in a second embodiment the screws 8 comprise a groove 8d (shown with a dashed line in figure 10) which separates the collar 8c from the head 8a, wherein the diameters of the head 8a and of the collar 8c of the screws 8 are substantially the same.

Referring also to figures 11 and 12, it can be seen that in a third embodiment the screws 8 comprise a head with a non-circular external profile, for example in the shape of a six-pointed star (Torx).

Any variants or additions may be made by the skilled persons to the embodiments described and illustrated herein remaining within the scope of the following claims. In particular, further embodiments may comprise the technical features of one of the following claims with the addition of one or more technical features described in the text or illustrated in the drawings, taken individually or in any reciprocal combination.