“CLOSURE FOR PRESSURIZED DUCTS”

DESCRIPTION

The present invention concerns a closure for pressurized ducts or receptacles. More in detail, the invention relates to a “quick opening” closure, i.e., which allows access to the inside of said duct or receptacle and subsequent re-closing thereof with a few simple operations.

Pressurized ducts of small, medium and large size, for example for transporting pressurized fluids such as (liquid or gaseous) fuels or the like, are generally provided with one or more branches communicating with the inside of the duct.

These branches define openings or accesses through which it is possible to insert equipment into the duct to carry out inspection, cleaning and/or maintenance operations or, in other cases, they can allow connection to other portions of duct or of other components of the plant, such as valves or the like.

These branches generally comprise a tubular section, which couples on the lateral surface of the main duct, on the free end of which there is applied a closure that allows said section of pipe to be sealed when the duct is filled with pressurized fluid.

In many cases, these accesses or openings and the relative closures are also placed in an end section of said duct.

In industrial plants in which the operating pressures are low or medium, for example below 300 bar, in the majority of cases these accesses are closed using “blind flange” closures.

These closures comprise an annular supporting flange, placed at the opening and joined in one piece with the junction or with the duct (typically by means of welding), and a disc flange, which acts as closing element, in jargon “blind flange”, coupled to the annular flange by means of bolts. A gasket that guarantees the hermetic seal of the closure is interposed between the annular flange and the disc flange.

However, these known closures have some drawbacks.

Depending on their size, and more precisely the diameter of the duct or of the branch section, the closing element is clamped against the supporting and blocking element with a number of bolts that varies from a few up to a few tens of bolts.

To remove said closing element, for example to carry out inspection or maintenance operations of the section of duct or for other needs, it is therefore necessary to release and remove all the bolts present. After the operation to close the closure said bolts must be clamped again.

When these operations that require opening of the duct are frequent, or in any case not rare, the opening and closing operations are considerably time consuming.

In addition to this, to release and re-clamp the bolts, the operator must be equipped with specific wrenches and/or other suitable tools.

Moreover, in many cases, these closures are placed in environments in contact with aggressive or corrosive agents that, over the course of time, corrode the surfaces of the screws and of the nuts of the bolts making the clamping and release operations more time- consuming, laborious and complicated. The larger the size of the closure (diameter of the duct) and hence of the bolts, the more serious these conditions are.

Finally, with these known closures, after each opening, i.e. after removal of the closing element, and before the subsequent reclosing thereof, the gasket must be replaced. In some cases, these operations may require to be carried out urgently or without prior programming, and the operator might not have a spare gasket available, resulting in downtime of the plant while waiting for the gasket to be sourced.

In this context, the object of the present invention is to provide a closure for pressurized ducts or receptacles that overcomes the aforesaid limits of the prior art.

The object of the present invention is therefore to produce a closure that can be opened and closed with a few simple operations, without the aid of specific tools.

Another object of the present invention is to provide a reliable closure, with parts that are not subject to wear and, therefore, which does not require maintenance or restoration operations.

Yet another object of the present invention is to produce a closure that is safer for the operators carrying out the opening and closing operations.

In addition to the aforesaid, an object of the present invention is also to provide a closure that is simple and economical to produce.

Finally, but no less important, an object of the invention is to provide a kit for converting a closure of known type described above into a closure that overcomes all the aforesaid drawbacks.

These objects are achieved by a closure for ducts or receptacles for pressurized fluids in conformity with the appended claim 1. Said objects are also achieved by a kit in conformity with the appended claim 10.

In particular, according to the invention, said closure comprises: a fixed part, to be applied at an end of a section of a tubular element, said fixed part defining an opening communicating with the duct or receptacle; a moving part, rotatably connected to said fixed part, with the possibility of moving between a closed position and an open position; and a sealing element to be placed in the opening of the fixed part.

In the open position of the moving part, the sealing element can be inserted into or removed from the opening. In the closed position, the moving part blocks said sealing element in the opening.

The closure according to the present invention can be applied to ducts or receptacles destined to transport or contain pressurized fluids such as (liquid or gaseous) fuels, chemical substances, steam, water or the like. More generally, the closure according to the invention can be applied to hollow bodies destined to contain a pressurized fluid, whether static or moving.

Therefore, in the description below, the term "duct" or "pressurized duct" refers to a generic hollow body among those cited above. The term “tubular element” refers to the portion of pipe to which the fixed part of the closure is connected; this tubular element can be part of the pressurized duct or receptable or can be a branch or other element communicating therewith.

The fixed part, at the opening, comprises a sealing surface produced on the inner surface, which includes a cylindrical section of the axis X that extends from the opening toward the tubular element.

Said sealing element comprises a body in the shape of disc or cylinder adapted to coact with said sealing surface to guarantee the hermetic seal of the closure.

Preferably, the body of the sealing element has an outer diameter slightly smaller than the diameter of the sealing surface. Typically, the difference between said diameters varies from a few tens of millimeters up to 1 millimeter or more, based on the size of the closure.

Therefore, the sealing element can be positioned in the opening, or removed therefrom, without effort, when the moving part is in open position. More in detail, the sealing element is inserted into or extracted from the sealing surface with a linear movement along the axis X of the sealing surface.

According to an aspect of the invention, on the perimeter surface of the sealing element there is produced a seat adapted to house a gasket which, when the sealing element is in the opening, is in contact with the sealing surface of the fixed part to guarantee the hermetic seal of the closure.

The sealing element comprises an inner face which, when it is arranged in the opening, is facing the inside of the duct, and an outer face, facing the moving part.

When the moving part is in closed position, and the sealing element is placed in the opening, said outer face is close to an inner side of the moving part.

More in detail, when a pressurized fluid is present in the duct, it exerts an outward thrust on the inner face of the sealing element, i.e., against the inner side of the moving part. Therefore, the function of the moving part is to withstand the thrust exerted by the fluid on the sealing element and prevent it from escaping from the opening.

From the closed position, to open the closure it is sufficient to rotate the moving part to the open position and remove the sealing element from the opening. To reclose the closure, it is sufficient to reposition the sealing element in the opening and rotate the moving part again to the closed position.

The operations described above can be carried out simply and rapidly by a single operator and without the aid of tools. Moreover, as the moving part is connected to the fixed part, there is no risk of it being dropped by the operators during the opening and closing operations, falling and injuring operators or in any case becoming damaged.

Additionally, as the gasket of the sealing element is not subject to compression, it does not require to be replaced at each opening but, on the contrary, has a useful life that substantially depends on the time and on the type of pressurized fluid present in the duct and on the operations carried out by the operator.

According to another aspect of the invention, the fixed part, the moving part and the sealing element are made of metal, preferably steel. In some applications in which pressures are limited, said parts can also be made of other materials, for example polymers with adequate mechanical strength.

According to another aspect of the invention, connection means of gripping means can be present on the outer face of the sealing element, which allow the sealing element to be placed in the opening or removed therefrom in a more practical way, especially when its size, and hence its weight, are substantial.

Said connection means can, for example, comprise a threaded hole into which a handle can be screwed.

According to another aspect of the invention, the sealing element is provided with a stop edge adapted to abut against a respective abutment edge of the fixed part. This arrangement facilitates correct positioning of the sealing element in the opening by the operator and prevents this element from becoming jammed following a misalignment with respect to the sealing surface.

According to another aspect of the invention, the moving part is connected to the fixed part so as to rotate about an axis Xr parallel to the axis X of the sealing surface.

More in detail, the moving part can be pivoted on the fixed part so that from the open position, in which said moving part is arranged at the side of the opening and does not interfere with the passage of the sealing element, it can rotate to the closed position, in which its inner side is facing said opening, so as to prevent the sealing element from escaping from the opening.

This configuration can be adopted as between the outer face of the sealing element and the inner side of the moving part no gaskets or other sealing means are present to guarantee sealing of the closure.

This joint is particularly simple and economical to produce and practical to implement.

According to an embodiment of the invention, the fixed part comprises an annular flange provided with a coupling neck that allows connection, typically by means of welding, with the tubular element of the pressurized duct. Said flange and said neck have respective continuous and connected inner surfaces on which the sealing surface is produced.

The moving part instead comprises a disc flange, i.e., substantially flat and circular in shape.

According to an aspect of the invention, the fixed part or the moving part, or both, comprise at least one blocking element that defines a seat adapted to house at least one section of the perimeter edge of the moving part or of the fixed part, respectively, when the moving part is rotated in closed position.

Said blocking element is configured to constrain the two parts, fixed and moving, along a direction parallel to the axis X of the sealing surface. In practice, said blocking element has the task of receiving at least a part of the thrust that the pressurized fluid in the duct exerts on the sealing element which, in turn, presses against the inner side of the moving part.

According to an aspect of the invention, said blocking element comprises a curved profile with a U-shaped, L-shaped C-shaped or similar section, fixed at the perimeter edges of the annular flange of the fixed part or of the disc flange or, according to a preferred variant, of both.

Said profile can be fixed to the respective annular flange or disc flange by means of bolts, can be welded to said parts or, optionally, can be made in one piece therewith.

When the moving part is in the closed position, the perimeter edges of the annular flange and of the disc flange are received in the seat formed by the respective profile fixed on the other part and are maintained blocked along the axis X by at least one strip of said profile.

In practice, blocking of the moving part of the closure along the axis X takes place simply by taking it from the open position to the closed position by means of a rotation about the axis Xr. As can be understood, this operation is much quicker and more practical to carry out with respect to those required to open and close known closures equipped with bolted flanges.

According to a preferred variant, the profiles of the blocking elements fixed to the moving part and to the fixed part, respectively, have an extension of around 180° and are arranged so that, when the moving part is in closed position, they substantially completely encircle the perimeter edges of the annular flange and of the disc flange. According to an aspect of the invention, the moving part can rotate with respect to the fixed part by means of a hinge interposed between the two blocking elements fixed to the fixed part and to the moving part, respectively.

According to this variant, said blocking elements also act as supporting elements to connect the moving part to the fixed part.

According to a particular embodiment of the present invention, the closure described above can be obtained thanks to a kit for converting an existing closure of known type.

In detail, the kit according to the invention can be applied to closures with bolted flanges of the type described above, i.e., comprising an annular supporting flange connected to the tubular section and a closing element in the form of disc flange.

According to this variant, the kit comprises a first supporting and blocking element, a second supporting and blocking element, rotatably connected to the first, and a sealing element.

The first supporting and blocking element is adapted to be fixed on the annular flange of the closure while the disc closing element is fixed to the second supporting and blocking element.

As in the previous variant, the sealing element is adapted to be placed in the opening of the annular flange and to coact with the inner surface thereof, which acts as sealing surface. Also in this case, it is preferably provided with an annular gasket adapted to contact the sealing surface.

Also in this variant, the first and second supporting and blocking elements comprise curved profiles, with a U-shaped, L-shaped, C-shaped or other suitably shaped section, fixed to the perimeter edge of the annular flange and of the disc flange.

This variant in the form of a kit is particularly advantageous to act on existing plants equipped with bolted flange closures of known type. In fact, thanks to the aforesaid kit it is possible to re-use the parts of the existing closure, when they are not excessively worn or damaged, and produce a closure according to the present invention, with a considerable saving of cost.

According to another aspect of the invention, the closure can be equipped with a safety device which prevents opening thereof when pressurized fluid is present in the duct.

This safety device comprises a cap that can be housed in a vent hole produced in the fixed part. Preferably, the vent hole and a portion of the cap can be coupled by means of threads. Said vent hole is a through hole and places the inside of the duct in communication with the outside environment. In general, said vent hole is produced in the neck section that extends from the annular flange toward the pressurized duct.

According to the invention, the safety device further comprises a blocking pin, integral with the cap, adapted to engage a blocking bracket, in turn connected to the moving part.

When the closure is in operating condition, the cap of the safety device closes the vent hole and the blocking pin engages the blocking bracket preventing rotation of the moving part toward the open position.

In order to open the closure, it is necessary, as first action, to remove the cap from the vent hole to disengage the blocking pin from the blocking bracket. In this way, if there is still pressurized fluid in the duct, it would be ejected through the vent hole warning the operator of the risk of opening the closure in these conditions. In the case in which there is only a residual pressure in the duct, this can in any case be discharged through the vent hole before opening the moving part and removing the sealing element.

This safety device can also be provided in the variant in the form of kit. In this case, in addition to the operations of fixing the supporting and blocking elements to the annular and disc flanges, it is necessary to produce the vent hole in the neck of the annular flange.

According to another aspect of the invention, the closure can be equipped with a counterweight connected to the moving part, more precisely to the blocking element fixed to the disc closing element. This counterweight is preferably provided when the closure is arranged vertically or in positions close to the vertical, i.e., when the moving part rotates about a substantially horizontal axis Xr.

In this condition, the counterweight facilitates the operations to rotate the moving part between the open and closed positions, counterbalancing a part of the weight of said moving part, especially when the closure is of large size.

Further features and advantages of the present invention will be more apparent from the description of an example of a preferred embodiment of a closure for pressurized ducts, as illustrated in the accompanying figures, wherein:

- Fig. 1 is a perspective view of a closure according to the invention, in closed position;

- Figs. 2a and 2b are respective perspective views of the closure according to the invention, in respective stages of opening;

- Fig. 3 is a sectional view of the closure of Fig. 1;

- Fig. 4 is a perspective view of a closure according to another embodiment of the invention, in open position.

With reference to the accompanying Figs. 1 to 4, the number 1 indicates as a whole a closure for ducts or receptacles for pressurized fluids, such as fuels, chemical products, gases, steam, water or the like. In the example illustrated, the closure is applied at the end of a tubular element 100. As stated above, depending on the context of use, the tubular element 100 can be a part of said duct or receptacle or can be another element communicating therewith as a branch, a coupling or the like.

The closure 1 comprises a fixed part 10 and a moving part 30, hinged about a substantially horizontal rotation axis Xr. The closure further comprises a sealing element 40.

The fixed part 10 comprises an annular flange 11 that defines an opening 12 communicating with the tubular element. A neck 13, which is welded to the end 101 of the tubular element 100, extends from the rear side of the annular flange 11. The opening 12 is delimited by an inner cylindrical surface 14 of the axis X, hereinafter defined sealing surface.

The fixed part 10 further comprises a first blocking element 15 fixed to the annular flange 11, for example by means of bolts or by means of welding.

In the example of the figures, said blocking element 15 comprises a semi-circular curved profile with a U-shaped section. This profile 15 is fixed to the perimeter edge 11c of the flange 11 so that a first lateral wall 15a of the profile 15 is placed close to a rear face lib of the annular flange 11. The section of the profile 15 has a width greater than the thickness of the annular flange 11 so as to form a seat 16 between said annular flange 11 and a second wall 15b of the profile, opposite the first wall 15a.

The moving part 30 comprises a flat and circular shaped disc flange 31. This disc flange 31 is fixed to a second blocking element 35.

Also the second blocking element 35 comprises a semi-circular profile with the U- shaped section.

Also in this case, this profile 35 of the moving part 30 is fixed to the perimeter edge 31c of the disc flange 31 so that a first lateral wall 35a of the profile 35 is placed close to a front face 31a of the disc flange 31. The section of the profile 35 has a width greater than the thickness of the disc flange 31 so as to form a seat 36 between said disc flange 31 and a second wall 35b of the profile, opposite the first wall 35a.

The profiles 15 and 35 are fixed to the respective annular 11 and disc 31 flanges by means of bolts; as stated previously, said profiles 15, 35 can also be welded or produced in one piece with the respective flanges.

When the fixed part 10 is rotated in the closed position, as in Figs. 1 and 3, a section of the perimeter edge 11c of the annular flange 11 is received in the seat 36 of the profile 35 and a section of the perimeter edge 31c of the disc flange 31 is received in the seat 16 of the profile 15.

The two flanges 11, 31 are thus maintained facing by the profiles 15, 35, which prevent them from moving away in the direction of the axis X.

The profiles 15, 35 of the blocking elements are joined by a hinge 20 with a rotation axis Xr. In Figs. 1 to 3 this rotation axis is substantially horizontal.

The moving part 30 can thus rotate with respect to the fixed part 10 in a substantially vertical plane between the open position, where it is arranged at the side of the opening 12, as shown in Figs. 2a, 2b, and the closed position, shown in Figs. 1 and 3, where it is facing the opening 12 and the sealing element 40 housed therein.

As explained previously, the hermetic seal of the closure 1 is guaranteed by the sealing element 40, which is housed in the opening 12 and is adapted to coact with the sealing surface 14 produced in the fixed part 10.

The sealing element 40 comprises a substantially flat circular body 41. On the perimeter edge 42 of the body there is produced a seat 43 in which an annular gasket 44 is housed.

When the sealing element 40 is arranged in the opening 12, as in Fig. 3, its rear face 46 is facing the tubular element 100 and its front face 45 is facing the outside or the disc flange 31 of the moving part. The sealing element 40 is also provided, at the front face 45, with a stop edge 47 which extends radially. Said stop edge 47 abuts against a respective abutment edge 18 of the annular flange 11 when the sealing element is inserted in the opening 12.

Preferably, on the front face 45 of the sealing element 40 there is produced a threaded hole 49, which acts as connection means that allows the connection of gripping means, such as a handle or the like, to place or remove said sealing element 40 in/from the opening 12.

When the closure is operative, and pressurized fluid is present in the duct, the sealing element 40 is thrust by the fluid against the inner face 31b of the disc flange 31. This thrust is opposed by the blocking elements, and more precisely by the profiles 15, 35, which retain the flange close to the annular flange 11.

The closure 1 further comprises a safety device 50 comprising a vent hole 51 that passes through the thickness of the neck 13 of the fixed part 10 and places the inside of the duct in communication with the outside environment. The safety device further comprises a threaded cap 52, that can be screwed into the vent hole 51, which comprises an outer extension 53 in the form of blocking pin.

Said blocking pin 53. when the cap 52 is inserted into the vent hole 51 and when the moving part 30 is in closed position, engages a seat 56 of a blocking bracket 55 connected to the profile 35 of the moving part 30. In this condition the blocking pin prevents the rotation of the moving part 30. To release this rotation it is necessary to remove the cap 52 and the blocking pin 53 connected thereto.

According to a preferred embodiment, the moving part 30 is provided with a counterweight 60 preferably fixed to the profile 35 close to the hinge 20.

Said counterweight 60 comprises a curved plate 61 with an inner profile 62 having a diameter substantially the same as the outer diameter of the profile 11 of the fixed part 10.

In this way, when the moving part 30 is in open position, said counterweight 60 abuts with the inner profile 62 against the outer surface of the profile 11 and adheres thereto, as can be seen in Figs. 2a, 2b.

Fig. 4 illustrates the closure according to a variant of the invention. According to this embodiment, the closure is identical to the one described previously, except for the absence of the counterweight 60.

This variant is suitable for horizontal positioning of the closure, i.e., with the moving part 30 that rotates about a substantially vertical axis Xr. In these conditions, the weight of the moving part 30 affects the opening and closing operations to a lesser extent and the counterweight is not required.

The invention has been described for non-limiting illustrative purposes, according to some preferred embodiments. Those skilled in the art may find numerous other embodiments and variants, all falling within the scope of protection of the appended claims.