WO2016067207A1

WO2016067207A1 - Tank for containing under pressure fluids and method for obtaining the same

Info

Publication number: WO2016067207A1
Application number: PCT/IB2015/058296
Authority: WO
Inventors: Matteo Hee Seung ILLESI
Original assignee: I.H.P. Composite S.R.L.
Priority date: 2014-10-28
Filing date: 2015-10-28
Publication date: 2016-05-06
Also published as: EP3212987A1

Abstract

The present invention concerns a tank for containing high pressure fluids delimiting a fluid sealed internal housing compartment (RZ), the tank comprising a tubular body (2) and two containment heads (4), one head being connected to an annular end (2c) of the tubular body (2) and the other head being connected to or made in a single piece with the other annular end (2c) of the tubular body (2). The tank also comprises an external covering layer (7).

Description

"TANK FOR CONTAINING UNDER PRESSURE FLUIDS AND METHOD

FOR OBTAINING THE SAME"

Designated inventor: ILLESI MATTEO HEE SEUNG

TECHNICAL FIELD OF THE INVENTION

The present invention concerns a tank for containing high and very high pressure fluids, for example methane or GPL.

STATE OF THE ART

Many tanks for containing pressurised gases or liquids, such as methane, have been proposed, which comprise many layers so as to constitute a reinforced structure.

In this respect, usually tanks comprise an inner layer comprising a tube, possibly metallic, two heads connected to the metallic tube as well as an external layer wrapped around the metallic tube.

However, such tanks have structures that are often difficult to make and assemble.

Moreover, most tanks proposed up to now do not ensure good stability in raised position and must be laid down or in any case rested on a respective cylindrical side wall.

FR1272354A teaches a tank that has a pair of heads made of plastic material connected to a cylindrical liner made of plastic. Moreover, between each head and a respective end of the liner sealant can be applied.

The heads also comprise an annular lateral wall with a plurality of cylindrical portions having different diameters, so that between adjacent and consecutive cylindrical portions a respective annular shoulder is delimited.

Around the liner a tubular component is then provided made of cardboard, said tubular component being brought into abutment against the edge of the heads.

The tank also comprises a first internal covering layer and a second external covering layer that are applied over and around the liner, tubular component and part of the heads.

More specifically, the first internal covering layer comprises a mat obtained by applying unidirectional filaments, for example made of fibreglass, which extend "axially" and are bonded or fixed to a support sheet.

On the other hand, as far as the second external covering layer is concerned, it is applied on the first internal covering layer, so as to radially clamp (with reference to the longitudinal axis of the tank) the first internal covering layer and increase the engagement of the latter with the cylindrical portions of the heads.

Such a tank has a rather complex structure and, moreover, is difficult to obtain considering the fact that it comprises two covering layers to be applied in sequence. Moreover, in the tank taught by FR1272354A a good seal is not ensured, both due to the materials and the engagement between first layer and heads.

PURPOSES OF THE INVENTION

A purpose of the present invention is to provide a new tank for containing pressurised fluids.

Another purpose of the present invention is to provide a tank as stated above that can be assembled quickly and easily.

Another purpose of the present invention is to provide a tank that can be arranged both in raised or vertical position and laid down or horizontal position, always ensuring good stability during transportation and in the place of use.

Another purpose of the present invention is to provide a tank that is very strong and capable of safely containing high or very high pressure fluids.

Another purpose of the present invention is to provide a new method for making a tank.

Another purpose of the present invention is to provide a new method for making a tank equipped with a core, which is simpler and more cost-effective to obtain with respect to conventional processes.

In accordance with an aspect of the invention a tank is provided according to claim 1.

In accordance with an aspect of the invention a method for making a tank is provided according to claim 23.

The dependent claims refer to preferred and advantageous embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the present invention will become clearer from the description of embodiments of a tank, illustrated for indicating purposes in the attached drawings, in which:

- figure 1 is a perspective view slightly from above of a tank according to the present invention;

- figure 2 is a section view of an enlarged detail of the tank of figure 1 ;

- figure 3 is a view of the detail of figure 2 to which the external covering layer has not yet been applied;

- figure 4 is a view similar to figure 1 of another embodiment of the tank according to the present invention;

- figure 5 is a section view of an enlarged detail of the tank of figure 4;

- figure 6 is a view of the detail of figure 5 to which the external covering layer has not yet been applied;

- figure 7 is a view similar to figure 1 of a further embodiment of the tank according to the present invention;

- figures 8 and 9 are views of the tank of figure 7 during respective construction steps;

- figure 10 is a view of a detail, partially in section and in enlarged scale, of the tank of figure 7;

- figure 11 is a front view of figure 10;

- figures 12 and 13 are views similar, respectively, to figures 10 and 11 but relative to another embodiment of the tank according to the present invention;

- figures 14 and 15 are views similar, respectively, to figures 2 and 3, but they refer to another embodiment of the tank according to the present invention;

- figures 16 to 18 illustrate respective steps for obtaining a tank according to the present invention. In the attached drawings, parts or components that are the same are marked by the same reference numerals.

EMBODIMENTS OF THE INVENTION

With reference first to figures 1 to 6, a tank 1 for containing high pressure 5 fluids is illustrated, delimiting a fluid sealed internal housing compartment RZ.

Thus, the tank 1 comprises a cylindrical container with an external surface comprising a substantially cylindrical lateral face la and two main faces, optionally substantially flat or slightly curved lb and joined through the substantially cylindrical lateral face la.

i o The tank preferably comprises a tubular body 2, for example made of metallic material, optionally steel, extending around a main longitudinal axis x-x and delimiting a gap or axial gap 3.

The tubular body preferably has a substantially cylindrical configuration with constant diameter or section and has an external lateral face 2a, an internal 15 face 2b as well as a pair of annular ends 2c.

Two containment heads or flanges 4, optionally made of metal, are also provided, a head 4 being connected to a respective annular end 2c of the tubular body 2, whereas the other head 4 is connected or in a single piece with the other annular end 2c of the tubular body 2. Preferably, each head 4 is connected (for 20 example as will be specified more clearly hereafter) to a respective annular end 2c of the tubular body 2.

The heads 4 also extend for an extension transverse or orthogonal to the main longitudinal axis x-x substantially equal to or greater than the section or width of the axial gap 3. This means that at least one head 4 and preferably both 25 the heads 4 have a respective portion or section substantially aligned in the direction of the longitudinal axis x-x with the axial gap 3 and, optionally, such head(s) 4 projects/project with respect to the axial gap 3. Thanks to such a provision, one or each head 4 is such as to oppose a resistance or containment force against the pressure of the fluid in the housing compartment RZ of the tank 30 for the entire extension transverse to the longitudinal axis x-x. The containment heads 4 each comprise an internal face 4a, an external face 4b as well as an edge portion 4c, preferably annular, said edge portion extending between the internal face 4a and the external face 4b. Preferably, the external faces 4b of the heads 4 constitute the two main faces lb of the tank. Advantageously, the external face 4b of at least one of the heads 4 is substantially flat or slightly curved.

The containment heads 4 can also comprise a solid of revolution around an axis of symmetry that, in use, corresponds to the axis x-x.

Optionally, the edge portion 4c of each head 4 is substantially aligned with the tubular body 2. Moreover, one or both of the heads 4 can comprise a substantially flat or slightly curved component extending mainly in a direction orthogonal or transverse to the longitudinal axis x-x. More specifically, the thickness of one or both the heads 4 can be greater at the edge portion 4c and progressively reduce in passing from the edge portion 4c to the centre of the head(s) 4. In this case, the internal face 4a of one or both of the heads 4 is substantially curved with concavity facing towards the inside of the housing compartment RZ.

Moreover, in the edge portion 4c of both of the heads 4 a channel or recessed portion or annular groove 5 is formed, which is substantially coaxial to the main longitudinal axis x-x or in any case extends around the longitudinal axis x-x.

One or both of the heads 4 preferably also delimit an axial hole 6 for the positioning of a respective filler (not illustrated in the figures), for example threaded and in which a valve for filling the tank with a pressurised fluid or dispensing the latter from the tank can be housed.

The tank 1 is also equipped with an external covering layer 7 obtained through the winding of composite material, which is obtained in a single piece in contact with or directly on the other components of the tank, i.e. making the winding in contact with or directly on the tubular body and on the heads assembled together. Moreover, the layer 7 wraps around the external lateral face 2a of the tubular body 2 as well as the edge portion 4c of both the heads 4, so as to engage and at least partially fill the respective channel, recessed portion or annular groove 5 and thus firmly constrain the external covering layer 7 to the containment heads 4, advantageously solely through the engagement between the channel or recessed portion or annular groove 5 and a respective end section 7b of the external covering layer 7. Preferably, the external covering layer 7 does not wrap around the external faces 4b of the heads 4, since thanks to the engagement of the end section 7b in a respective groove 5 the engagement of the external faces 4b is not also necessary.

Advantageously, but not necessarily, the channel or the recessed portion or the annular groove 5 is filled and engaged by the external covering layer 7 entirely, i.e. from one internal side 5a to the other external side 5b and from the bottom 5c to the top 5d thereof, by this meaning that the layer 7 extends for the entire width of the channel, the recessed portion or the annular groove 5 both in the direction of the axis x-x and transversely or orthogonally thereto. The engagement of the external covering layer 7 in the recessed portion or annular groove 5 of each head 4 ensures a constraint or hold of the covering layer 7 on both the heads 4 that is both stable and well distributed and simple and quick to carry out. This, if desired, can make it possible to obtain a constraint between heads 4 and covering layer 7 without it being necessary to apply other constraining components, such as fastening rings or clamps or layers between such elements, although, as it will be understood it is possible to apply a glue or adhesive between heads 4 and layer 7.

The external covering layer 7 is obtained through winding over the tubular body 2 and heads 4 through the so-called "filament winding" process or winding of continuous filaments. Preferably, the external face of the covering layer 7 constitutes the substantially cylindrical lateral face la of the tank.

Optionally, the external covering layer 7 has a first section 7a around the tubular body 2 having a first thickness SI, as well as a second section or end section 7b for engaging and filling each recessed portion or annular groove 5 and having a second thickness S2 greater than the first thickness S 1 and with internal surface closer to the main longitudinal axis x-x with respect to the internal surface of the first section 7a, as well as, optionally, with external surface substantially aligned with the external surface of the first section 7a or with the external face 2a. In this case, the external covering layer 7 has a different thickness and more specifically an enlarged end section 7b at each recessed portion or groove 5, in other words at the recessed portions or grooves 5 of both the heads 4.

Alternatively, the external covering layer 7 could also have a constant thickness from one end to the other, in which case the first section 7a would have a greater thickness with respect to the case described above and equal to the thickness of the second sections 7b.

According to the non-limiting embodiment illustrated in figures 1 to 3, at least one head 4 comprises an edge portion 4c including from a side, in use, proximal to the external face 4b to the other side, in use, distal from the external face 4b, a first length 4c 1, for example substantially cylindrical extending from an end of the external face 4b, a first shoulder 4c2, optionally frusto-conical and a second section 4c3, optionally substantially cylindrical and with an external diameter or section greater than the first substantially cylindrical length 4c f and joined to the substantially cylindrical first length 4c 1 through the first shoulder 4c2, with a substantially annular channel or recessed portion 5 being delimited between the substantially cylindrical first length 4cl and the first shoulder 4c2. The first shoulder 4c2 thus faces towards the external face 4b of the respective head.

The substantially cylindrical first length 4c 1 can, for example, be at a substantially constant distance from the longitudinal axis x-x, the first shoulder 4c2 can be at an distance from the longitudinal axis x-x increasing in the direction moving away from the respective first length 4c 1, whereas the substantially cylindrical second section 4c3 can be at a substantially constant distance from the longitudinal axis x-x.

Therefore, with such a structure, one or both of the main faces lb comprises/comprise an internal portion, optionally circular consisting of the external face 4b of a head and an annular sector around the latter consisting of the external covering layer 7 and more specifically an external portion of the second section 7b. The second section 7b instead comprises, moving away from the respective main face, a first annular part 7b 1, optionally with substantially constant section or diameter and then a second annular part 7b2, optionally tapered, for connecting the annular part with constant section or diameter with the first section 7a of the external covering layer 7.

Optionally, see in particular the non-limiting embodiment of figures 4 to 6, the edge portion 4c comprises from a side, in use, proximal to the external face 4b to the other side, in use, distal from the external face 4b, a flanged end 4c4 extending from an end of the external face 4b, then the substantially cylindrical first length 4c 1, the first shoulder 4c2 and the substantially cylindrical second section 4c3 and, in this case, the annular groove 5 is delimited between the flanged end 4c4, the substantially cylindrical first length 4c 1 and the first shoulder 4c2. The flanged end 4c4 can have a width greater than the second length 4c3 so as to have a free end part at a distance from the longitudinal axis x-x greater than the second section 4c3, optionally at a distance from the longitudinal axis greater than the second length 4c3 by an amount substantially equal to the first section 7a of the external covering layer 7.

If desired, the edge portion 4 also comprises a second shoulder 4c5 transverse or orthogonal to the longitudinal axis x-x as well as a third length, optionally substantially cylindrical 4c6 with an external diameter or section smaller than the substantially cylindrical second length 4c3 and joined to the latter through the second shoulder 4c5.

With such a structure, therefore, one or both of the main faces lb is/are delimited entirely by the external face 4b of a head.

In a tank according to the present invention, the channel or recessed portion or annular groove 5 is, basically, delimited by at least one shoulder 4c2 facing towards the external face 4b of the respective head 4 and facing away from the other head 4, so as to constitute a gripping or engagement point for a respective end section 7b of an external covering layer 7, so that the external covering layer 7 can oppose the axial stresses or forces applied to the heads 4 by the pressurised fluid in the tank.

As far as the connection of the tubular body 2 to one or both the heads is concerned, an annular end 2c of the tubular body 2 can be connected, for example welded or screwed or connected by interference or shape coupling or forced insertion to a respective portion of a head 4, for example at a section of the edge portion 4c. In this case, if a substantially cylindrical third length 4c6 is provided, an annular end 2c of the tubular body 2 can be wrapped around and connected, optionally welded or screwed or connected by interference or shape coupling or forced insertion, to the latter.

The heads 4 can be in a single piece, in other words a monoblock, or can be made of two or more parts or components 40a-40b.

If a head comprises two components 40a-40b, an external component 40a as well as an internal component 40b are provided, which internal component 40b is joined, for example welded or screwed or connected by interference or shape coupling or forced insertion to the tubular body 2. In this case, the external face 4b of the head 4 is the external face of the external component 40a, whereas the internal face 4a of the head 4 is the internal face of the internal component 40b and moreover the two external and internal components 40a, 40b are in contact with one another at a respective first 4e and second 4f intermediate face. Moreover, the edge portion 4c can consist of the edge portion of the external component 40a.

In this case, the external component 40a is brought into abutment or resting on the internal component 40b and the external component 40a of a head 4, indeed, has the function of transmitting to the internal component 40b a suitable resistance against the axial stresses imparted on it (to the external component 40a) by the composite material of the external covering layer 7 through engagement between an end section 7b and a groove or recessed portion 5. More specifically, the internal component 40b is configured for example like a hood, optionally made of metallic material, such as steel. The internal component 40b can have a curved plate-like configuration, suitably shaped so as to abut at its second intermediate face 4f against the first intermediate face 4e of a respective external component 40a. The internal component 40b can also have a first annular end 4g intended to be connected, optionally welded, for example butt-welded, to an annular end 2c of the tubular body 2.

The intermediate component 40b can also have a second intermediate or central end 4h surrounded by an intermediate or central section of the external component 40a for delimiting a respective axial hole 6, which intermediate end 4h can be shaped like a sleeve and, optionally, be internally threaded.

The tank can also comprise, in particular when the tubular body 2 is connected by screwing to one or more heads 4, a liner or inner core 8, optionally made of plastic, for example high-density polyethylene (HDPE), which lines the internal face 2b of the tubular body 2 so as to delimit, in a fluid sealed manner, the fluid housing compartment RZ of the tank, optionally in combination with the filler(s) positioned in the axial hole(s) 6. The inner core 8, if provided, can also cover the internal face 4a of at least one of the heads 4 or of the internal component 40b, if such a component is provided.

In this case, in order to obtain the liner or core 8, it can be directly moulded in the impression or the chamber delimited by both the heads connected to the tubular body 2. Basically, the heads 4 joined to the tubular body 2 can constitute the forming mould of the plastic liner 8.

As will be understood, unlike conventional processes, in which the core or liner constitutes the base component around which the tank is built, with a method according to the present invention, first the other components of the tank, i.e. the tubular body and the heads, are built and assembled and then the liner is built and formed inside the impression delimited by the other previously assembled components .

In this respect, once the tubular body 2 and head(s) 4 are connected so as to obtain a containment and moulding group delimiting a chamber or impression and provided with at least one inlet hole or opening 6, a power or a fluid of a plastic material is inserted, from an axial hole or opening 6, into the impression or the chamber delimited by them and then, optionally, the hole or opening 6 is closed and it is ensured that the power or fluid adheres to the inner walls of the containment heads 4 and of the tubular body 2, optionally by setting the containment and moulding group in rotation or by blowing, and then the powder or fluid is made to set or harden or is left to set or harden, for example by controlling the temperature of the group and/or by varying the pressure in the chamber, thereby obtaining a tank provided with the tubular body 2, with the two containment heads 4 and with the internal covering core or liner, as well as, optionally the external covering layer 7.

The internal covering core or liner obtained must cover all of the internal walls of the containment and moulding group in a substantially continuous manner and with substantially constant thickness and it must ensure a tight or pneumatic seal. Preferably, the liner has a thickness greater than 1 mm, and even more preferably more than 3 mm.

More specifically, according to a variant, the liner can be produced through a method in accordance with which, inside the chamber or impression of the containment and moulding group, a suitable amount of power is inserted and then the group is set in rotation so that the powder, as a function of the centrifugal force and the force of gravity as well as the heating thereof, is melted and spread or deposited on the internal walls of the containment and moulding group with a thickness that is even enough for the entire extension thereof (the extension of the layer of powder) .

Concerning this, the containment and moulding group can be mounted on an arm of a so-called "rotational" or rotary machine that makes the containment and moulding group rotate quickly and in different directions of rotation.

Moreover, the group is positioned and made to rotate, preferably, inside an oven for heating the group and, therefore, the powder. Moreover, a method for making a container as now described, equipped or not with the aforementioned external covering layer 7 or with annular grooves 5, is the subject-matter of the present patent application.

In one or both of the heads 4, in particular at the respective external face 4b it is also possible to form recesses, channels 10 or the like intended to constitute gripping handle points of the respective head 4.

As far as the relationship between the axial gap 3 and the housing compartment is concerned, the axial gap 3 can constitute part of the housing compartment RZ, more specifically, an intermediate part RZl thereof, whereas the remaining part RZ2 of the housing compartment RZ can be delimited and defined by the heads 4 or rather by the internal face 4a of one or both of the heads. More specifically, the housing compartment can comprise an intermediate part RZl substantially corresponding to the axial gap 3 as well as two end parts RZ2, one on the opposite side to the other with respect to the intermediate part RZl and each delimited by an internal face 4a of a respective head 4. Of course, the parts RZl and RZ2 are in fluid communication and constitute a housing compartment RZ that is substantially continuous and without fluid-interrupting baffles.

If there is an internal core 8, then, as stated earlier, it lines the internal faces 2b and 4a, respectively of the tubular body 2 and of the heads 4 and delimits the housing compartment RZ, in which case the intermediate part RZl of the housing compartment RZ will correspond to the axial gap 3 minus the thickness occupied by the internal covering core 8 of the internal face 2b.

With particular reference to the non-limiting embodiments illustrated in figures 7 to 14, a tank 1 according to the present invention has been illustrated similar to the tanks illustrated above, but also equipped with at least one external containment band 12, also formed through winding of continuous filament or filament winding of composite material and wound around the external walls of the tank.

Concerning this, the external containment band 12 comprises a substantially continuous band element having several sections, which has a width much smaller than the width of the tank, of the substantially cylindrical lateral face la and of the main faces lb. More specifically, the external containment band 12 includes longitudinal sections 12a wrapping around the substantially cylindrical lateral face la of the tank, as well as transverse sections 12b, 12c, 12d winding, from the external, the two substantially flat or slightly curved main faces lb thereof.

Advantageously, positioning seats or recesses 13 of the sections of the external containment band 12 are provided. Even more advantageously, the positioning seats 13 are provided in both of the heads 4. In each positioning seat 13 it is also possible to house two sections of the containment band, for example one on top of the other. More particularly, the external containment band 12 comprises a plurality of longitudinal sections 12a bridge-connected two by two through a respective transverse section 12b, 12c or 12d.

The transverse sections 12b, 12c, 12d formed in a head 4 can also be inclined with respect to one another and can cross over one another. According to the non-limiting example illustrated in figures 7 to 13, in one or both of the heads 4 there are two first transverse sections 12b parallel to one another, two second transverse sections 12c inclined, for example by about 90° with respect to the first transverse sections 12b as well as two third transverse sections 12d inclined with respect to the first 12b and second 12c transverse sections.

With such a structure, a containment band 12 extends from a first longitudinal section 12a, followed by a transverse section 12b, 12c or 12d in a first head 4, another longitudinal section 12a angularly spaced, with respect to the axis x-x, from the longitudinal section 12a described previously, a transverse section 12b, 12c or 12d in the second head 4, a further longitudinal section 12a followed by another transverse section 12b, 12c or 12d on the first head, angularly offset with respect to the aforementioned transverse section 12b, 12c or 12d formed in the first head and so on until the entire containment band is formed.

Basically, an external containment band 12 according to the present invention has a substantially continuous extension, but with sections having different extension from each other, particularly at the heads 4. In this case, the positioning seats 13 contain the filaments in position and prevent the entanglement of the filaments of different sections of the band 12.

An external containment band 12 and in particular the sections thereof are arranged around and so as to press from the outside, advantageously in a uniform and continuous manner for the entire extension of the band 12, respective components of the tank, in particular the heads 4 and the external covering layer 7. As will be understood, such a band makes it possible to obtain a tank having very high strength and capable of sealably and stably containing high and very high pressure fluids.

Now with reference to figures 14 and 15, another tank according to the present invention has been illustrated, similar to the tank of figures 5 and 6, but without a tubular body 2.

In this case, the heads 4 are connected to the core or liner 8 and the external covering layer 7 wraps around a second external lateral surface 8a of the core 8 as well as the edge portion 4c of each of the heads 4 so as to engage and at least partially fill the channel or recessed portion or annular groove 5 and thus firmly constrain the external covering layer 7 to the containment heads 4.

In this case, the core 8 extends around the main longitudinal axis x-x and delimits the gap 3 and, moreover, the containment heads 4 are connected, for example glued, welded or screwed, each to a respective annular end 8c of the core 8.

More specifically, the core 8 comprises a solid of revolution around an axis of symmetry that, in use, corresponds to the axis x-x and has a tubular section with greater diameter 8e, externally defining the second external lateral surface 8a of the core 8, then two plate-like sections 8f substantially orthogonal to the axis x- x and each extending from a respective end of the tubular section 8e towards the inside or towards the axis x-x. Each plate-like section 8f ends with a hollow tanglike section 8g with smaller diameter intended to engage, for example by screwing, with the wall of a respective head 4 delimiting an axial hole 6. Each of the annular ends 8c preferably comprises a plate-like section 8f and a respective tang-like section 8g.

As will be understood, the description provided now in detail for the core 8 also applies to the embodiments described earlier provided with tubular body 2. 5 According to the embodiment now under consideration, the recessed channel 5 is deeper, whereas the respective end section 7b has a thickness greater than the examples described earlier.

In accordance with such an embodiment, as a matter of fact, the core carries out the function of the tubular body of the examples described above and is i o constrained to the other components of the tank as described for the tubular body described above.

With reference now to figures 16 to 18, the steps for obtaining a tank according to the present invention or for carrying out a method in accordance with the present invention have been illustrated in detail.

15 Concerning this, it should be noted that the covering layer 7 of a tank according to the present invention basically comprises a filament or a plurality of continuous filaments or strands Fl wound one by one or individually around or rather directly around the containment heads 4 and the tubular body 2; the filament(s) Fl is/are covered before or after winding, through a settable fluid,

20 such as a resin, which once set or polymerised joins the filaments or strands or the sections of filament to one another and to the components of the tank 2 and 4 or 2 and 8, so as to harden or solidify the covering layer 7 on the components of the tank and constrain it to the latter.

More specifically, the covering layer 7 comprises a filament or a plurality

25 of continuous filaments or strands returned one or more times between one head 4 and the other with extension surrounding or wrapping around the main longitudinal axis x-x.

The expressions filament winding should be construed in this sense and in particular the term "continuous" indicates that the filament(s) or strand(s) is/are

30 unwound, for example from a reel and sent through suitable guide eyelets GE or return means towards the tank to be covered and then wound on it as stated above.

In order to do this, it is possible to assemble heads and tubular body or heads and core and mount them rotatably on a machine, then arrange a reel of filaments and a guide eyelet GE intended to send the filament(s) Fl between the reel and the tank. In order to obtain the covering it is possible, for example, to constrain, optionally with a suitable adhesive means, an end of one or each filament to the tank, for example to one of the heads, then set the tank in rotation and simultaneously move, longitudinally or parallel to the axis x-x, the guide eyelet GE, thereby obtaining the covering layer 7, filling the channel or recessed portion or annular groove 5. Alternatively, it is possible to mount the tank, able to rotate about a horizontal axis, on a support oscillating around a vertical axis, so that during the covering the eyelet can be kept immobile, while a continuous rotation is imparted on the tank around the horizontal axis and an oscillation is imparted around the vertical axis first in one direction and then in the opposite direction.

A tank according to the present invention can thus be assembled in a quick and simple manner, considering the fact that the external covering layer is fixed directly to the heads thanks to the channel or recessed portion. Such a provision allows a good grip of the external covering layer that, advantageously, does not require the provision of other components or elements, such as fastening annular elements or layers or the like for constraining the external covering layer to the heads or flanges.

In this respect, as already partly indicated above, a method for making a tank according to the present invention firstly foresees to provide the tubular body 2 and the containment heads 4, to then connect the latter to a respective annular end 2c of the tubular body 2. At this point the external covering 7 is made by winding one or more filaments of composite material directly, through filament winding on the external lateral face 2a of the tubular body 2 and on the edge portions 4c of the containment heads 4, so as to firmly constrain the external covering layer 7 to both of the containment heads 4, preferably solely through the engagement between channel or recessed portion or annular groove 5 and a respective end section 7b of the external covering layer 7. Advantageously, the method is carried out so that each end section 7b engages and fills a respective recessed portion or annular groove 5 entirely (in the sense indicated above). The winding, as stated above, is carried out substantially continuously, in other words winding the tank or the respective components 2 and 4 starting from one side or end of the tank up to the other and so on to carry out the desired passes, substantially in a single production step.

Basically, in a tank according to the present invention, the heads apply a resistant force against the thrust or force from the inside towards the outside of the pressurised fluid directed in a direction substantially parallel to the longitudinal axis x-x and for the entire width of the tank, while the external covering layer opposes the radial forces or thrusts, with reference to the longitudinal axis x-x, applied by the pressurised fluid to the tank. Each channel or recessed portion or annular groove 5 and in particular the shoulder 4c2 for delimiting it also constitutes a gripping or engagement point on the heads 4 for the external covering layer 7 or for the respective end sections 7b, so that the external covering layer 7 applies a resistant force to the axial stresses applied to the heads 4, so as to help them in their resistant and containment action and ensure that they are kept in position.

Moreover, a tank according to the present invention can be arranged both in raised position and in lowered position, always ensuring good stability during transportation and in the place of use, thanks to the structure and substantially flat or slightly curved configuration, in particular at the respective external face of at least one head.

A tank according to the present invention, moreover, is very resistant, both due to the structure and assembly of the heads, of the tubular body and of the external covering layer and, in particular thanks to the external containment band, if such a component is provided.

The method for producing a tank with a core according to the present invention also makes it possible to obtain the liner directly in the other components of the tank, thus without having to make a suitable mould to then extract the core therefrom and assemble it with the other components of the tank.

As far as FR1272354A is concerned, it regards a solution that is different and certainly less strong with respect to the present invention.

Concerning this, it does not comprise a covering layer as described above. Indeed, as far as the first layer of FR 1272354 A is concerned, it comprises a mat on which filaments are applied that are arranged parallel to the longitudinal axis of the tank and that are pressed radially by the second layer.

Therefore, the first layer is not obtained by winding one or more continuous filaments on the tank or rather on the other components of the tank, to then join the sections of the filament or of the filaments, thus forming the layer, but a preformed mat comprising pieces of filaments (and therefore not continuous filaments) embedded in a support sheet and having extension parallel to the axis of the tank. The filaments of the first layer of FR1272354A are therefore neither continuous filaments nor wound on the components of the respective tank.

The second layer of FR1272354 A, on the other hand, as far as understood, comprises filaments that are applied with circumferential extension on the first layer, and thus such a layer too is not said to be obtained through filament winding.

Moreover, the second layer of FR 1272354 A does not engage, let alone fill, the recessed portions of the heads of the respective tank.

Basically, the tank of FR1272354A comprises a pair of covering layers, one internal intended to engage the cylindrical portions of the heads, but obtained by applying a mat with pieces of axial or longitudinal filaments and the other external applied over the first layer and not intended to engage the heads, nor the recessed portions thereof.

Moreover, this turns out into an application of the first layer or inner layer to the group formed by heads, liner and tubular component that is much less stable with respect to that of a tank according to the present invention, considering, amongst other things, the fact that the inner layer is in any case unable to entirely fill the recessed portions of the heads, in other words the area defined between the cylindrical portions and the shoulders delimited between them. This is clearly visible also from the figures of FR1272354A, but, in any case, it is all too clear to see that a mat (as the first layer of FR1272354A is said to be made) cannot be adapted to the group formed by heads and liner, so as to adhere thereto in a complementary manner.

Moreover, the process for making the tank of FR 1272354 A is also more complex and comprises at least one step more (application of two layers) with respect to the method object of the present invention.

Modifications and variants of the invention are possible within the scope of protection defined by the claims.

Claims

1. Tank for containing high pressure fluids delimiting a fluid sealed internal housing compartment (RZ), said tank comprising:

- a tubular body (2) or a core (8) extending around a main longitudinal axis (x-x) and delimiting a gap (3);

- two containment heads (4), a containment head (4) being connected to an annular end (2c, 8c) of said tubular body (2) or of said core (8), while the other containment head (4) is connected or made in a single piece with the other annular end (2c) of said tubular body (2) or of said core (8), said heads extending for an extension transverse or orthogonal to said main longitudinal axis (x-x) substantially equivalent or greater than the section or width of said gap (3), each of said containment heads (4) comprising an internal face (4a), an external face (4b) and an edge portion (4c) extending between said internal face (4a) and said external face (4b), in said edge portion (4c) of each of said two heads (4) there being formed a channel or recessed portion or annular groove (5) substantially coaxial or extending around said main longitudinal axis (x-x),

- an external covering layer (7) obtained by filament winding, i. e. winding one or more continuous filaments made of composite material, said external covering layer (7) winding an external lateral face (2a, 8a) of said tubular body (2) or of said core (8) as well as said edge portion (4c) of each of said heads (4) so as to engage and at least partly fill said channel or recessed portion or annular groove (5) and thus firmly constrain said external covering layer (7) to said containment heads (4).

2. Tank according to claim 1, wherein each head (4) is constrained to said external covering layer (7) solely through the engagement between a respective channel or recessed portion or annular groove (5) and a respective end section (7b) of said external covering layer (7).

3. Tank according to claim 1 or 2, wherein said channel or recessed portion or annular groove (5) is filled and engaged by said external covering layer (7) entirely, i. e. from one internal side (5a) to the other external side (5b) and from the bottom (5c) to the top (5d) of said channel or recessed portion or annular groove (5).

4. Tank according to any one of the preceding claims, wherein said channel or recessed portion or annular groove (5) is delimited by at least one shoulder (4c2) facing towards the external face (4b) of the respective head (4) and facing away from the other head (4) of said two heads (4), so as to form a gripping and engagement point for a respective end section (7b) of said external covering layer (7).

5. Tank according to any one of the preceding claims, wherein said external covering layer (7) is constrained to said containment heads (4) solely through engagement between said channel or recessed portion or annular groove (5) and a respective end section (7b) of said external covering layer (7), and fastening rings or clamps or layers for constraining or connecting said covering layer (7) to said heads (4) are not provided.

6. Tank according to any one of the preceding claims, wherein said external covering layer (7) has a first section (7a) around said tubular body (2) and having a first thickness (SI), as well as a second section (7b) for engaging and filling said recessed portion or annular groove (5) and having a second thickness (S2) greater than said first thickness (SI) and with internal surface closer to said main longitudinal axis (x-x) with respect to the internal surface of said first section (7a).

7. Tank according to any one of the preceding claims, wherein the external face (4b) of at least one of said heads (4) is substantially flat or slightly curved.

8. Tank according to any one of the preceding claims, wherein at least one of said heads (4) comprises an edge portion (4c) including from one side, in use, proximal to said external face (4b) to the other side, in use, distal from said external face (4b), a first length (4c 1), a first shoulder (4c2) and a second length (4c3) with section or external diameter greater than said first length (4c 1) and connected to said first length (4c 1) through said first shoulder (4c2), said channel or recessed portion (5) being delimited between said first length (4c 1) and said first shoulder (4c2).

9. Tank according to claim 8, wherein said edge portion (4c) comprises from one side, in use, proximal to said external face (4a) to the other side, in use, distal from said external face (4b), a flanged end (4c4) extending starting from an end of said external face (4b), said first length (4c 1), said first shoulder (4c2) and said second length (4c3), said annular groove (5) being delimited between said flanged end (4c4), said first length (4c 1) and said first shoulder (4c2).

10. Tank according to claim 8 or 9, wherein said at least one edge portion (4) comprises a second shoulder (4c5) transverse or orthogonal to said longitudinal axis (x-x) as well as a third length (4c6) with section or external diameter smaller than the section or the external diameter of said second length (4c3) and connected to said second length (4c3) through said second shoulder (4c5).

11. Tank according to any one of the preceding claims, wherein at least one annular end (2c, 8c) of said tubular body (2) or of said core (8) is welded or screwed or connected by interference or shape coupling or forced insertion to a length (4c6) of a head of said heads (4).

12. Tank according to any one of the preceding claims, comprising a core (8) which lines an internal face (2b) of said tubular body (2) and intended to fluid sealingly delimit said housing compartment (RZ) of said tank.

13. Tank according to claim 12, wherein said core (8) also lines said internal face (4a) of at least one of said heads (4).

14. Tank according to any one of the preceding claims, wherein at least one of said heads (4) comprises an external component (40a) and an internal component (40b) joined to said tubular body (2), the external face (4b) of said at least one head (4) comprising the external face of said external component (40a), while the internal face (4a) of said head (4) is the internal face of said internal component (40b), said external (40a) and internal (40b) components being in contact with each other at a respective first (4e) and second (4f) intermediate face.

15. Tank according to any one of the preceding claims, comprising at least one external containment band (12) formed by winding one or more continuous filaments made of composite material around the external faces (la, lb) of said tank.

16. Tank according to claim 15, wherein said external containment band (12) comprises a substantially continuous band element having several longitudinal sections (12a) winding a substantially cylindrical lateral face (la) of said tank, and

5 having transverse sections (12b, 12c, 12d) winding, from the external, two substantially flat or slightly curved main faces (lb) of said tank.

17. Tank according to claim 16, comprising positioning seats or recesses (13) for positioning said sections (12b, 12c, 12d) of said external containment band (12), said positioning seats (13) being provided for in one or both of said heads i o (4).

18. Tank according to claim 16 or 17, wherein said external containment band (12) comprises a plurality of longitudinal sections (12a) bridge connected two by two through a respective transverse section (12b, 12c or 12d).

19. Tank according to claim 18, wherein said transverse sections (12b, 12c, 15 12d) are inclined with respect to each other and cross one with the other.

20. Tank according to any previous claim, wherein said external covering layer (7) is obtained in contact with or directly on said containment heads (4) and said tubular body (2) or on said containment heads (4) and said core (8), i.e. obtaining the winding of one or more continuous filaments in contact with or

20 directly on said tubular body (2) and said containment heads (4) assembled one with the other or on said core (8) and on said containment heads (4) assembled one with the other.

21. Tank according to any previous claim, wherein said covering layer (7) comprises a filament or a plurality of continuous filaments or strands (Fl) wound

25 one by one or individually around said containment heads (4) and said tubular body (2) or about said containing heads (4) and said core (8).

22. Tank according to any previous claim, wherein said covering layer (7) comprises a filament or a plurality of continuous filaments or strands returned one or more times between one head (4) and the other with extension surrounding said

30 main longitudinal axis (x-x).

23. Method for obtaining a tank according to any one of the preceding claims, comprising the following steps:

- providing said tubular body (2) and said containment head (4) or said core (8) and said containment head (4) and connecting a containment head to an annular end (2c, 8c) of said tubular body (2) or of said core (8), while the other containment head is connected or made in a single piece with the other annular end (2c, 8c) of said tubular body (2) or of said core (8); and

- obtaining said external covering layer (7) by filament winding, i. e. by winding one or more continuous filaments made of composite material directly on or in contact with said external lateral face (2a, 8a) of said tubular body (2) or of said core (8) and on at least said edge portion (4c) of said containment heads (4), thereby engaging and at least partly filling said channel or recessed portion or annular groove (5) of said heads (4) so as to firmly constrain said external covering layer (7) to said containment heads (4).

24. Method according to claim 23, wherein said covering layer (7) is obtained winding a filament or a plurality of continuous filaments or strands (Fl) one by one or individually around said containment heads (4) and said tubular body (2) or about said containing heads (4) and said core (8) and then joining them one with the other by setting a settable fluid.

25. Method according to any previous claim, wherein said covering layer (7) is obtained by returning one filament or a plurality of continuous filaments or strands one or more times between one head (4) and the other with extension surrounding said main longitudinal axis (x-x).

26. Method for obtaining a tank for containing high pressure fluids, comprising the following steps:

- providing a tubular body (2) extending around a main longitudinal axis (x-x) and delimiting a gap (3);

- providing two containment heads (4) and connecting one head to an annular end (2c) of said tubular body (2), while the other head is connected or made in a single piece with the other annular end (2c) of said tubular body so as to obtain a containment and molding group delimiting a chamber or impression and provided with at least one introduction hole or opening (6);

- introducing inside said chamber or said impression through said at least one introducing hole or opening (6) a powder or a fluid made of plastic material;

5 - making said powder or said fluid to adhere to the internal walls (2b, 4a) of said tubular body (2) and said two containment heads (4);

- hardening or solidifying said powder or said fluid, or allowing said powder or said fluid to harden or solidify so as to form a core or liner (8) with airtight or pneumatic sealing for internal lining said tubular body (2) and said two i o containment heads (4), thus obtaining a tank provided with said tubular body (2), said two containment heads (4) and said core or liner (8), said core or liner (8) covering all the internal walls of said containing or molding group in a substantially continuous manner and with a substantially constant thickness.

27. Method according to claim 26, wherein said core or liner (8) comprises a 15 thickness greater than 1 mm and preferably greater than 3 mm.

28. Method according to claim 23 for obtaining a tank according to claim 12 or 13, wherein before obtaining said external covering layer (7) a step is provided for molding said core (8) through a method according to claim 26 or 27.

20