WO2017212369A1

WO2017212369A1 - Method for the production of a sleeve suited to join two facing pipe segments.

Info

Publication number: WO2017212369A1
Application number: PCT/IB2017/053150
Authority: WO
Inventors: Alessandro Condini; Alexey Zhuravlev
Original assignee: Mpr S.R.L.
Priority date: 2016-06-09
Filing date: 2017-05-29
Publication date: 2017-12-14
Also published as: ITUA20164245A1

Abstract

The invention includes a method for making a sleeve (1, 100) suited to join the facing ends (201 a, 202a) of two pipe segments (201, 202). The method includes the steps of preparing an outer tubular element (2), preparing an inner tubular element (3) made of a deformable material whose outer diameter (d1 ) is smaller than the inner diameter (d2) of the outer tubular element (2) and whose length (11 ) exceeds the length (I2) of the outer tubular element (2), coaxially inserting the inner tubular element (3) along the outer tubular element (2), deforming the inner tubular element (3) so that it adheres firmly to the inner surface (2c) of the outer tubular element (2) and so as to create two outer seats (4), and installing two tubular elastomers (5) in said outer seats (4).

Description

METHOD FOR THE PRODUCTION OF A SLEEVE SUITED TO JOIN TWO

FACING PIPE SEGMENTS.

DESCRIPTION

The invention relates to a method for producing a sleeve suited to join the facing ends of two pipe segments belonging to a pipeline, preferably for hydrocarbons.

The invention also relates to the sleeve obtained utilizing the above mentioned method.

Additionally, the invention relates to a pipeline, preferably for hydrocarbons, comprising at least two pipe segments arranged side by side and joined together by means of the above mentioned sleeve.

It is known that in a variety of applications, such as in the extraction and transport of hydrocarbons, particularly oil and gas, it is necessary to use a pipeline whose inner surface is coated with a material able to withstand the corrosion provoked by the flow of such hydrocarbons.

It is also known that these hydrocarbon transport lines are constructed by joining a plurality of pipe segments, two by two. In particular, the joint in question is obtained by means of a welding line at the level of the facing ends of two adjacent pipe segments. However, the creation of the welding line to join the two facing ends of two pipe segments poses two well-known drawbacks.

The first drawback lies in that, along said welding line, the inner surface of the pipeline is not provided with the above mentioned corrosion-resistant coating. Therefore, this joint is certainly a weak point of the pipeline itself.

In addition, the second drawback lies in that the heat generated by the welding process could deteriorate the protective coating even in the inner areas adjacent to said welding lines.

In order to overcome the above mentioned drawbacks, the use of special joining elements, known as internal sleeves in technical jargon, is known, which are installed at the level of said inner welding areas, so as to prevent those areas from coming into direct contact with the corrosive fluid flowing through the pipeline.

In particular, it is known that also the inner surface of said internal sleeves is coated with the same type of corrosion-resistant coating used for the pipeline's inner surface. In addition to the above, the internal sleeves of the prior art have frustoconical ends diverging outwards, so as to define a variation of the diameter compared to the inner diameter of the linear pipeline and to prevent the generation of turbulence phenomena in the fluid flowing inside the pipeline, which could accelerate the deterioration of the inner surface of the pipeline itself.

Furthermore, it is known that the outer surface of said sleeves is equipped, at the level of said ends, with gaskets of the O-ring type housed in suitable seats defined on said surface.

In the center of said outer surface of the sleeve there is a ring, substantially made with the same metallic material with which the pipeline is made, on which one or more teeth, projecting in the radial direction, are secured generally by means of welding. These teeth have the purpose, when the sleeve is used to join said two pipe segments, of being interposed between the two facing ends of said pipe segments, so as to create an annular groove within which the welding line is successively carried out.

In addition to the above, the projecting teeth made on the ring keep the sleeve stationary inside the pipeline.

This kind of internal sleeve of the prior art, although very effective in its function, has a significant drawback, which is constituted by the complexity of its production method.

In fact, briefly, according to the prior art, to construct this type of sleeve as a first step it is necessary to mill a solid element to shape the body of the sleeve itself.

In particular, this milling operation has the object of defining the frustoconical ends diverging toward the outside, the external seats on which the O-ring gaskets will be placed and the toothed metal ring. Furthermore, the production process of the internal sleeve of the prior art requires that the inner surface of the sleeve itself be treated so as to cover it with the protective corrosion- resistant layer. Additionally, it is necessary to place the two gaskets in the above mentioned seats and secure the toothed ring.

All of this, disadvantageously, results in increased production time and therefore a cost that is far from negligible.

In addition to the above, the weight and thickness of said sleeve are considerable.

The present invention intends to overcome all the above mentioned drawbacks.

In particular, it is one of the objects of the invention to provide a method for making an internal sleeve suited to join the facing ends of two pipe segments which makes it possible to reduce production times compared to the prior art. It is a further object of the invention to provide a method for the production of said sleeve which makes it possible to avoid production waste.

Consequently, it is one object of the invention to provide a method for making said sleeve which makes it possible to reduce production costs.

Yet another object of the invention is to provide a method for making said sleeve of the invention which makes it possible to obtain a lighter and more compact structure of said sleeve compared to the sleeves of the known art.

The objects illustrated above are achieved by the production method in accordance with the main claim.

Further characteristics of the method of the invention are described in the dependent claims.

Furthermore, said objects are achieved with the sleeve obtained by applying the above mentioned method in accordance with claim 10 and with the pipeline, preferably for hydrocarbons, comprising at least two pipe segments facing each other and joined together by interposing the above mentioned sleeve in accordance with claim 1 1 .

The above mentioned objects, together with the advantages that will be illustrated below, are highlighted in the description of two preferred embodiments of the invention that are provided by way of non-limiting example making reference to the attached drawings, wherein:

- Figure 1 a shows the side view of a first example of embodiment of a sleeve made with the method of the invention;

- Figure 1 b shows the side sectional view of the sleeve shown in Figure 1 according to the cross-section line A-A;

- Figure 2 shows the side sectional view of a second example of embodiment of a sleeve made with the method of the invention;

- Figure 3 shows an axonometric view of the external tubular element, in particular the annular crown, belonging to the sleeve shown in Figures 1 a and 1 b;

- Figure 4 shows an axonometric view of the internal tubular element belonging to the sleeve shown in Figures 1 a and 1 b; - Figures from 5 to 8 show the execution steps of the method of the invention for making the sleeve shown in Figures 1 a and 1 b;

- Figure 9 shows an axonometric view of the external tubular element belonging to the sleeve shown in Figure 2;

- Figure 10 shows an axonometric view of the internal tubular element belonging to the sleeve shown in Figure 2;

- Figures 1 1 and 12 show the execution steps of the method of the invention for making the sleeve shown in Figure 2;

- Figure 13 shows a hydrocarbon pipeline in which the sleeve shown in Figures 1 a and 1 b is used to join two pipe segments;

- Figure 14 shows a hydrocarbon pipeline in which the sleeve shown in Figure 2 is used to join two pipe segments.

The sleeves according to two preferred embodiments, obtained by implementing the production method that is the subject of the invention, are shown in their final configuration respectively in Figures 1 a and 1 b and in Figure 2, where they are indicated as a whole by 1 and 100.

Specifically, the sleeve 1 shown in Figure 1 enables two pipe segments arranged coaxially side by side to be joined, while the sleeve 100, which represents a so-called elbow sleeve, enables two pipe segments arranged orthogonally to each other to be joined.

Moreover, Figures 5 to 8 show the sequence of the operating steps of the method of the invention for making the sleeve 1 shown in Figures 1 a and 1 b. In the same way, Figures 1 1 and 12 show the sequence of the operating steps of the method of the invention for making the sleeve 100 shown in Figure 2. As described with regard to the prior art, the sleeves 1 and 100 obtained through the method of the invention are configured to join the facing ends 201a and 202a of two pipe segments 201 and 202 belonging to a pipeline 300 and 400, preferably for hydrocarbons, as respectively shown in Figure 13 and Figure 14.

As for the method of the invention, the first operating step consists in preparing an outer tubular element 2. This outer tubular element 2, as can be seen in Figures 13 and 14, is configured to come into contact, through at least one portion of its side ends 2a and 2b, with both facing ends of the two pipe segments 201 and 202 to be joined when the sleeve 1 is used to create said joint. Preferably, the above mentioned outer tubular element 2 is made of a metallic material of the same type used for the pipe segments 201 and 202. It is not excluded that, according to different embodiments, the outer tubular element 2 may be made of a metallic material other than that used for making said pipe segments 201 and 202.

Additionally, it is not excluded that for alternative embodiments the material with which said outer tubular element 2 is made is not of the metallic type, but for example plastic.

Specifically, with respect to the first example of sleeve 1 of the invention, as shown in Figure 3, said outer tubular element is shaped like an annular crown 7 from the outer surface 7a of which one or more teeth 6 project radially.

In particular, said annular crown 7 is preferably made from a metal plate cut by laser.

As for the second example of embodiment of the sleeve 100 of the invention, said outer tubular element 2 is shaped like an elbow pipe 8, as can be seen in Figure 9.

According to the method of the invention, an inner tubular element 3 made of a deformable material is successively prepared. Said inner tubular element 3 is sized so that its outer diameter d1 is smaller than the inner diameter d2 of the outer tubular element 2. In addition to the above, the inner tubular element 3 must be shaped so that its length 11 exceeds the length or thickness I2 of the same outer tubular element 2. Thus, the above characteristics allow the next step of the method of the invention to be carried out, which involves inserting the inner tubular element 3 coaxially along the outer tubular element 2, in such a way that both ends of the inner tubular element 31 and 32 project with respect to the outer tubular element 2. This step is shown in Figure 5 with respect to the first example of the sleeve 1 of the invention and in Figure 1 1 with respect to the second example of the sleeve 100 of the invention. In particular, with regard to the production method of said second example of the sleeve 100, the latter may preferably but not necessarily include the pre- shaping of the inner tubular element 3 before said insertion step, so as to create a curvature that enables it to be easily inserted in the above mentioned outer tubular element 2.

As for the inner tubular element 3, in both of the examples of embodiment described herein it is preferably but not necessarily obtained from a flat steel sheet folded on itself so as to form a ring.

In particular, according to the preferred embodiment of the invention, said steel sheet is a stainless steel sheet.

However, it is not excluded that said sheet of steel may be of another pretreated type able to withstand the corrosive action of hydrocarbons and be folded on itself so as to define the tubular shape of the inner tubular element 3 only after that treatment.

Returning to the method for the production of the sleeve 1 and 100 of the invention, after the insertion of the inner tubular element 3 in the outer tubular element 2, the former is deformed so that its outer surface 3a adheres firmly to the inner surface 2c of the outer tubular element 2, as shown in Figure 7. In addition to the above, this deformation must be carried out in such a way that the projecting ends 31 and 32 of the inner tubular element 3 take on a frustoconical shape diverging outwards, defining two outer seats 4, respectively shown in Figure 8 with respect to the first example of embodiment of the sleeve 1 and in Figure 12 with respect to the second example of embodiment of the sleeve 100 of the invention.

According to the preferred embodiment of the invention, said deformation step is carried out by applying increasing pressure to the inner surface 3b of the inner tubular element 3 itself.

Even more specifically, said pressure increase is carried out and the resulting deformation of the inner tubular element 3 is achieved through a hydroforming process.

Clearly, the use of the hydroforming technique to deform the inner tubular element 3 involves inserting both the outer and inner tubular elements 2 and 3 in a negative mould having the shape of the desired end piece. After that, high pressure hydraulic pistons inject a fluid under very high pressure inside the inner tubular element 3, so as to expand it until it takes on the shape of the mould.

In further detail, the method of the invention for the production of the sleeve 1 of the first example provides for the use of a mould 500, schematically represented in Figure 7, which enables the outer tubular element 2 in the form of an annular crown 7 to be housed in a special central seat 501 , at the sides of which the same mould 500 has two further seats 502, so that when the inner tubular element 3 is deformed two projections 33 and 34 are created which are suited to adhere firmly to and thus hold said annular crown 7.

The mould 500 itself is then shaped at the ends 503 and 504 so as to define the above mentioned frustoconical shape of the ends 31 and 32 of the inner tubular element 3.

As regards the mould, not shown in the figures, for the execution of the hydroforming step related to the sleeve 100 of the second example of embodiment, since the central part of the inner tubular element 3 must adhere to the inner surface 2c of the outer tubular element 2, it must exclusively be shaped so as to enable the frustoconical shape diverging outwards and hence the seats 4 at the level of the ends 31 and 32 to be defined on the inner tubular element 3 itself, as shown in Figure 12.

Nonetheless, in general it is not excluded that, according to different embodiments of the invention, this shaping step may be carried out by means of techniques other than hydroforming.

Returning to the method of the invention, it includes a final step which involves installing two tubular elastomers 5 in the outer seats 4. Said tubular elastomers 5, as will be described in detail below, have the function of increasing the tightness of the joint between the ends of the pipe segments 201 and 202 to be joined together.

According to the preferred embodiment of the method of the invention, said installation of the two tubular elastomers 5 on the outer seats 4 is carried out by means of a hot-shrinking process involving the expansion of the tubular elastomers 5, so as to facilitate their insertion into said seats 4. Clearly, as the tubular elastomers 5 cool down, they will resume their natural shape, fully adhering to the outer surface of said seats 4.

As noted above, the sleeves produced with the method of the invention described above are also part of the invention. In particular, the two examples of embodiment of the sleeve 1 and 100 shown respectively in Figures 1 a and 1 b and in Figure 2 are part of the invention.

Finally, the pipelines 300 and 400 for hydrocarbons comprising at least two pipe segments 201 and 202 are also included in the invention, as shown respectively in Figure 13 and Figure 14.

According to the invention, in the pipelines 300 and 400 the two pipe segments 201 and 202 are joined together through the interposition of the sleeve 1 and the sleeve 100, respectively, as shown in Figures 13 and 14. Specifically, in both cases, the joint first requires that the ends of both pipe segments are fitted on the ends of the sleeve 1 and 100, over the tubular elastomers 5 until the end 201a and 202a of each pipe segment 201 and 202 comes into contact with at least one portion of the side ends 2a and 2b of the outer tubular element 2.

As mentioned above, said tubular elastomers 5 advantageously make it possible to obtain a coupling with optimal tightness between both the pipe segments and the sleeve.

When these three elements are arranged in the final position, their final coupling requires that said annular welding line 9 be created at the level of the contact area between the side ends 2a and 2b of the outer tubular element 2 and the ends 201a and 202a of the two pipe segments 201 and 202.

Therefore, according to the above description, the method of the invention, the sleeve of the invention and the pipeline of the invention achieve all the set objects.

In particular, the object to provide a method for making an internal sleeve suited to join the facing ends of two pipe segments which makes it possible to reduce production times with respect to the prior art is achieved.

The object of the invention to provide a method for making said sleeve which makes it possible to limit production waste is also achieved.

Consequently, the object to provide a method for making said sleeve which makes it possible to reduce production costs is also achieved.

Finally, the object to provide a method for making said sleeve of the invention which makes it possible to obtain a lightweight structure of the latter is also achieved.

Claims

1 ) Method for the production of a sleeve (1 , 100) suited to join the facing ends (201 a, 202a) of two pipe segments (201 , 202) belonging to a hydrocarbon pipeline (300, 400) characterized in that it includes the following steps:

- preparing an outer tubular element (2) configured to come into contact, through at least one portion of its side ends (2a, 2b), with both of said facing ends (201 a, 202a) of said two pipe segments (201 , 202) when said sleeve (1 ) is used to create said joint;

- preparing an inner tubular element (3) made of a deformable material, said inner tubular element (3) being sized so that its outer diameter (d1 ) is smaller than the inner diameter (d2) of said outer tubular element (2) and so that its length (11 ) exceeds the length (I2) of said outer tubular element (2);

- inserting said inner tubular element (3) coaxially along said outer tubular element (2), so that both ends (31 , 32) of said inner tubular element (3) project with respect to said outer tubular element (2);

- deforming said inner tubular element (3) so that the outer surface (3a) of said inner tubular element (3) adheres firmly to the inner surface (2c) of said outer tubular element (2), and so that said ends (31 , 32) projecting from said inner tubular element (3) take on a frustoconical shape diverging outwards, creating two outer seats (4);

- installing two tubular elastomers (5) in said outer seats (4).

2) Method according to claim 1 , characterized in that said inner tubular element (3) is made from a flat steel sheet folded on itself so as to form a ring.

3) Method according to claim 2, characterized in that said steel sheet is a stainless steel sheet.

4) Method according to any of the preceding claims, characterized in that said deforming step is carried out by applying increasing pressure on the inner surface (3b) of said inner tubular element (3).

5) Method according to claim 4, characterized in that said increasing pressure and said deformation of said inner tubular element (3) are obtained by means of a hydroforming process.

6) Method according to any of the preceding claims, characterized in that said outer tubular element (2) is shaped like an annular crown (7) from the outer surface (7a) of which one or more teeth (6) project radially. 7) Method according to any of the claims from 1 to 5, characterized in that said outer tubular element (2) is shaped like an elbow pipe (8).

8) Method according to any of the preceding claims, characterized in that said outer tubular element (2) is made of a metallic material.

9) Method according to any of the preceding claims, characterized in that said arrangement of said two tubular elastomers (5) on said outer seats (4) is carried out by means of a hot-shrinking process involving the expansion of said tubular elastomers (5).

10) Sleeve (1 , 100) characterized in that it is constructed by means of the production method according to any of the preceding claims.

1 1 ) Pipeline (300, 400) for hydrocarbons, comprising at least two pipe segments (201 , 202) facing each other, characterized in that said two pipe segments (201 , 202) are joined together through the interposition of a coupling sleeve (1 , 100) according to claim 10.