DE69000534T2 - FLEXIBLE TUBE WITH AT LEAST ONE LENGTHENING REINFORCEMENT ELEMENT WITH T-PROFILE. - Google Patents

Description

The invention relates to a flexible pipe with an elongated reinforcing element having a (straight) cross-section in "T" shape.

According to the state of the art, the flattened reinforcement profiles used for the flexible tubes are either "S" or "Z" shaped, which are difficult to manufacture and to insert accurately and stably under helical winding, or they are "U" shaped, and in the latter case they do not provide optimal performance for the thickness of the given layer. The thickness of the "U" profile requires in fact to be flattened in order to accommodate the legs of the "U" of the adjacent windings.

Flattened "U" profiles are shown in the earlier patent specification FR-2 561 745.

In the present text, an elongated reinforcing element may be designated by the terms "profile element" or "profile" or "profiled".

The invention relates to a flexible reinforced pipe with an elongated reinforcing element which is easy to manufacture for installation and, once in place, is stable and allows a favorable optimization of the performance for a given layer thickness.

In addition, a profile according to of the invention the contact pressures between adjacent reinforcing elements, as can be observed in the case of "Z" or 'S" profiles.

Furthermore, the device according to the invention does not require the use of a plurality of rings.

In general, the present invention relates to a flexible reinforced pipe with at least one elongated reinforcing element.

According to the invention, the elongated element has a cross-section or profile that is in the shape of a "T" and is wound in a helical manner.

This elongated "T"-shaped element can be metallic.

At least one edge of the elongated element may have a shape designed to cooperate with a complementary shape to achieve the interlocking.

The complementary shape can be supported by the edge of another elongated element with a cross-section in "T" shape, this element being applied with the opposite sense.

The complementary shape can be carried by the edge of an elongated element, which can be metallic and which has a "U"-shaped cross-section. The elongated "U"-shaped element can be arranged so that the legs of the "U" are directed outwards, or so that the legs of this "U" are directed towards the axis of the tube, the elongated "T"-shaped element then being arranged in a suitable manner.

If the legs 1 of the "U" element are directed towards the axis of the tube (i.e. the "U" element is arranged externally relative to the "T" element with which it interacts), its role can be limited to holding in position adjacent threads or wires of "T" shape. In this case, the "T" elements absorb the main forces due to internal pressure and the "U" profile can be dimensioned accordingly, i.e. the surface area of the "U" cross-section can be reduced in relation to that of the "T".

The "U" element can be made of plastic or steel or aluminium.

The tube according to the invention can comprise two elongate elements each having a cross-section of "T" shape; these elements are wound helically in the same direction, the first has its part of the cross-section corresponding to the foot of the "T" directed towards the axis of the tube and the similar part of the second element is directed in the opposite direction.

These elongated elements can have "T" profiles of equal height.

The first and second elongated elements may have the same cross-sectional shape, i.e. the cross-sections may have the same dimensions.

The first and second elongated elements may be metallic.

The first elongated element may have a modulus of elasticity that is less than that of the second element.

The first and second elongated elements may have the same modulus of elasticity.

The width of the part of the first element corresponding to the foot of the "T" may be greater than the width of the similar part of the second element.

The first and second elongated elements can be designed and dimensioned in such a way that they undergo the same elongation when subjected to the internal pressure of the tube, without there being a significant transmission of force from one of these elements to the other through the respective edges of each of these elements.

The tube according to the invention can comprise aluminum and/or steel. In particular, at least one of the elongated elements having a "T" profile can be made of or comprise metal, for example steel or an aluminum alloy.

At least one elongate reinforcing element may comprise essentially aluminium or an aluminium alloy.

The ratio of the length (1) of the arm of the "T" to the height (e) of the "T" can be between 0.5 and 1 and advantageously between 0.66 and 1.

The ratio of the width of the foot (P) to the length of the arms (1) can be between 1 and 3.

The ratio of the width of the foot (P) of the "T" to the height (e) can be between 0.66 and 3.

The ratio of the width (L) of the head of the "T" to the height (e) of the "T" can be between 1.66 and 5.

The width (L) of the head of the "T" is further designated by the width (L) of the "T".

The ratio of the height (h) of an arm to the height (e) of the "T" can be between 0.66 and 0.83.

The ratio of the height of an extension of the arm (C) to the height (e) of the "T" can be between 0.16 and 0.66 and advantageously close to 0.33.

The ratio of the radial clearance between two 'T's inserted head-to-toe to the width of the 'T' can be between 2% and 10%.

The pipe according to the invention can comprise an internal pressure-resistant reinforcement or bulge or curvature with at least one elongated element with a "T" profile.

The pipe according to the invention may comprise a "T" shaped profile having a reinforcement angle substantially greater than 80º and preferably 85º with respect to the axis of the flexible pipe.

The pipe according to the invention can comprise at least one reinforcing sheet and an internally sealed casing which bears against this sheet, which is also referred to as the inner sheet.

This inner track may comprise a plurality of elongated elements with "T" profile. This inner track may comprise axial interlocking means.

The tube according to the invention can comprise several reinforcing webs and, among these webs, only the inner web can comprise axial interlocking means.

The pipe according to the invention may comprise two reinforcing webs, one of which corresponds to said inner web, the elongate elements of said inner web being arranged at a first angle in a first direction relative to the pipe axis and the elongate elements of the second web may be wound at a second angle in opposite directions, one of which angles may be greater than or substantially equal to 55º and the other may be less than or substantially equal to 55º.

The tube according to the invention can comprise two pairs of webs, one of which webs corresponds to this first inner web, each of the webs comprising one and the same pair of elongate reinforcing elements wound at equal angles but in opposite directions, and this angle of one of these pairs can be greater than or substantially equal to 55º and the angle of the other pair can be less than or substantially equal to 55º.

The present invention also relates to wires or threads or an elongated element for the manufacture of flexible tubes, said wires having a "T" profile.

The material of the wires according to the invention or the geometry of the profile of these wires can correspond to that described in the previous pages and relative to the elongated element.

The tube according to the invention may comprise an inner carcass with a resistance to external pressure, which comprises at least an elongated element with a profile in "T" shape.

The present invention preferably comprises the structures of reinforced flexible "multi-lane" pipes, which essentially comprise:

- a reinforcement with a resistance to pressure with one or more rings or wires, cables or cables wound at an increased angle with respect to the axis of the flexible pipe (this angle may exceed 80 or 85º), and this angle is related to the axis of the flexible tube,

- a reinforcement with tensile strength comprising at least two strips and preferably one or more pairs of strips of crossed threads, cables or profiles, generally wound at an angle less than or close to 55º, but not too small to maintain the flexibility of the cable,

- an internal reinforcement of this inner carcass which is particularly resistant to crushing pressures; it is generally made up of a sheet of helical winding of a profile at an increased angle.

These different tracks can be arranged in any order from the inside to the outside of the structure of the flexible tube and can optionally be separated from each other by thin plastic sheaths. Such structures have been described, for example, in patent FR 1 417 966.

It should be noted that the "T" profile according to the invention practically does not exhibit the phenomenon of overlap, i.e. once in place on the flexible pipe, it does not tend to twist on itself. This allows in particular the use of a simple reinforcement device for inserting the "T" profile on the flexible pipe.

The "T" arrangement does not tend to spiral around itself. It is also possible to create a flexible pipe without tension reinforcement, the longitudinal ground effect is resumed at the level of the hooking. Of course, this flexible pipe can be used for any diameter considered in terms of operating pressure be limited.

Furthermore, the invention also relates to flexible pipes with at least one elongated element with a "T"-shaped cross-section, which is laid at all reinforcement angles, including 55º. This is possible in particular due to the fact that the "T" profile presents practically no problems of overlap.

Due to this fact, it is possible to consider increasing the working pressures of flexible pipes with two reinforcement sheets by limiting the clearances in the sheet in contact with the sealing sheath.

Finally, the "T" profile makes it possible to use profile widths (i.e. length of the crossbar of the "T") that are significantly larger than those permitted by other profiles, for example "S" and "Z" profiles.

The "T" profile can have a reinforcement angle substantially greater than 80º and preferably 85º, relative to the axis of the flexible pipe. In this case, the resistance to axial stresses is mainly ensured by the tensile reinforcements.

The tube may comprise an elongate member having a "T" profile, and this elongate member may be wound at an angle adjacent to 55º considered with respect to the axis of the flexible tube.

The tube may comprise two reinforcing sheets, at least one of which will comprise a plurality of elongated elements with a "T" profile, wound at an angle of 55º in a first direction with respect to the axis of the tube. This first sheet will also comprise a plurality of elongated elements complementary to those mentioned above, optionally having a "T" profile. The other The web will comprise a plurality of elongated elements wound at an angle of 55º in the opposite direction to the direction of the first web.

The angles of each of the tracks of the track pair do not need to be symmetrical with respect to the axis of the flexible tube.

In this case, the winding angle of one track can be greater than 55º, the other less than 55º, these angles are considered relative to the axis of the tube.

Preferably, the elongated element having a "T" profile can be used to form the pressure-resistant reinforcement and/or the inner carcass.

The accompanying figures show flexible reinforced pipes or tubes to which the invention is applicable, as well as particular examples, which are not to be considered limiting, of profiles of elongated elements:

Fig. 1 shows a first type of flexible reinforced pipes or tubes,

Fig. 2 and 3 show other types of lines,

Fig. 4 shows a configuration example of the cross-section or an elongated element according to the invention,

Fig. 5 to 7 show different designs of profiles,

Fig. 8 relates to a flexible pipe with a reinforcement armouring comprising two strips of elongated elements arranged at an angle of 55º relative to the axis of the flexible pipe, each wound on both sides of this axis, and

Fig. 9 relates to an embodiment of a flexible tube with a pair of asymmetrical paths in their winding direction.

In Fig. 1, reference numeral 1 indicates an internal duct which can be made of a plastic material, for example polyamide 11. This duct is covered with a pressure-resistant reinforcement 2 which, according to the example shown, is formed by winding a preformed profile wound in a spiral at an angle which, for example, exceeds 85º with respect to the axis of the duct.

The whole is covered with a kind of tensile-resistant reinforcement 3, which is formed by two crossed strands 3a and 3b made of profiles or elongated elements, which are wound spirally in opposite directions in the two webs.

Usually the winding angle of these profiles has a value between 20 and 50º, relative to the axis of the cable.

An outer shell, for example made of polyamide 11 or polyethylene, covers the entire structure.

Another type of flexible reinforced pipe is shown in Fig. 2. The same numerals are used in this figure to designate the elements analogous to those shown in Fig. 1.

In this second type of flexible cable, the tensile reinforcement comprises two pairs of crossed strips 3a, 3b and 3c, 3d made of profiles wound helically at an angle that may be between 20 and 50º with respect to the axis. In the type shown in Fig. 3 a steel carcass 5 is arranged inside the plastic pipe 1 and the sheets 2a and 2b of the internal pressure-resistant reinforcement are arranged on both sides of the tensile-resistant reinforcement 3a, 3b.

According to the invention, at least one web of wound profiles or elongated elements has a "T" profile, as shown in Fig. 4.

In this Fig. 4, which is a section through an elongated element, the letter L designates the width "T", it corresponds to the head 6 of the "T", the letter e designates the height of the "T", the letter "P" designates the width of the foot of the "T". The letter 1 designates the length of the arm 8 of the "T". The letter h designates the height or thickness of an arm 8 of the "T". The letter c designates the height of the base 9 of the arm 8 of the "T".

The dotted line 10 corresponds to a "T" profile, which has no approach for which c is equal to zero.

The reference numeral 11 indicates the cross-section of the "T" as a whole, this cross-section belonging to a given elongated element. The reference numeral 12 indicates the "T" profile of another elongated element which cooperates with the given elongated element. These two elongated elements are arranged head-to-toe, i.e. for one, the foot 7 of the "T" profile is oriented towards the outside of the tube and for the other, the foot 13 is oriented towards the axis of the tube 14. These elongated elements are considered to be complementary to each other.

If these elements comprise profiles with arms with lugs 9, an axial interlocking of the profiles occurs, ie the axial displacement of a profile 11 with respect to the adjacent profile 12 is the limit of the distance between these two profiles. These approaches thus correspond to interlocking or engagement means.

Of course, the approach of these two profiles is limited by the edge of a projection 9 of the "T" which rests against the adjacent foot 13.

Fig. 5 shows the case of a web with two elongate elements 15 and 16 having the same head-to-toe cross-sections 17 and 18. As can be seen from Fig. 5, one finds alternatively the elongate elements 15 and 16, each turn of the element 15 being enclosed by turns of the element 16, and each turn of the element 16 being enclosed by turns of the element 15.

Fig. 6 represents the case where the two elongated elements 19 and 20 have different cross-sections 21 and 22, but in this figure the two profiles 21 and 22 have one and the same height e.

Furthermore, in this figure, the width L of the "T" profile 22 of the elongated element 20 has substantially the same value a as the width p of the foot of the "T" profile 21 of the elongated element 19 (Fig. 6).

Furthermore, it remains within the scope of the invention if the two elongated elements have different mechanical characteristics, in particular as regards the modulus of elasticity, or if they are made of different materials. Thus, the elongated element 20 can have a modulus of elasticity that is greater than that of the elongated element 19.

In Fig. 6, 14 indicates the axis of the flexible tube.

Fig. 7 shows the case of an elongated element 23 with a "T" shaped profile 24 with lug 25 where the elongate element 23 is wound helically adjacent, ie that one edge of one arm of the elongate element is in contact or nearly in contact with the other edge of the adjacent turn of that elongate element.

The elongated element 23 is hooked together by a complementary elongated element 27 with a "U" profile 28.

The reference numeral 14 indicates the axis of the flexible tube. In Fig. 7, the arms 29 move away from the axis 14.

It is not outside the scope of the invention if the elongated elements are mounted in opposite directions, i.e. if the arms of the "U" are directed towards the axis of the tube.

The elongated elements 23 and 27 can be metallic and consist, for example, of steel and/or aluminum.

Furthermore, it does not depart from the scope of the present invention if the elongated element with a "T" profile is made of a metal and the elongated element with a "U" profile is made of a plastic material, for example a thermoplastic.

The elongated element with a straight cross-section or "T" profile of the flexible tube according to the invention preferably complies with one or more of the following conditions: * Radial clearance between 2% and 10%.

Radial clearance is the distance travelled radially by the "T" profile before it is immobilised by the adjacent immobile profile which is set at the height e of the "T" profile.

The starting point of this displacement is a straight line on which the "T" profile and the adjacent profile are supported, this clearance being designated by the reference j in Fig. 4, and the straight support line being designated by the reference 30.

This straight line corresponds essentially to the generatrices of the cylinder on which these elongated elements are wound, at least when the winding angle is large.

An estimate of the behavior of these two elongated elements with "T"-shaped cross-sections or "T" profile, identical and arranged head-to-toe (Fig. 5), was made and the internal diameter was set at 95.4 mm.

These elongated elements were made of steel, the Young’s modulus of the elongated elements was 200 MPa, the Poisson’s number was 0.3.

The "T" profile is characterized by L = 14.2; e = 6.2; P = 2.85; l = 5.67; h = 3.80; c = 1.64. Under an internal pressure of 20 MPa, the radial displacement of the wire or thread is 0.060 mm, that of the wire 15 is 0.0085 mm. The two profiles are therefore not in contact, this for a clearance of 0.246 mm.

Since the clearance is 0.246, the contact is set for an internal pressure of 95 MPa.

For an internal pressure of 20 MPa, the circumferential stresses of the wire 15 are at an average level of 33 MPa. They vary by +18% around this value as a function of the position in the "T" cross-section.

The mean level of hoop stress of wire 16 is 235 MPa and the stresses vary by +6% around this value.

The "T" profile as described in the invention is particularly well suited for compression reinforcements 2 and can preferably have a winding angle equal to or greater than 55º. It is also possible to preferably use the "T" profile to form the inner carcass as shown at 5 in Fig. 5.

Fig. 8 shows an embodiment of a flexible, particularly advantageous line, which has an inner tube 40, which can be made of plastic material, for example polyamide 11, a reinforcement 41 composed of two crossed webs 41a and 41lb, which are wound helically at an angle of 55° with respect to the axis 42 of the flexible structure.

Thus, these two tracks 41a and 41b form a pair of tracks, each of which comprises elongated elements wound at one and the same angle, in this case 55º, but each of these tracks is wound in an opposite direction and symmetrical with respect to each other.

At least one of these tracks, and in particular the inner track 41a, comprises a plurality of interlocking "T" profiles. These profiles can be interlocked by an equal number of complementary profiles having a cross-section or profile of "T" shape, as shown in Fig. 5, or of "U" shape, as shown in Fig. 7, depending on whether the arms of the "U" are oriented against the axis of the tube, if any.

The layer 41b may have the same structure or it may be a flat wire, round wire or other form thereof, possibly without entanglement. This wire is wound at an angle of approximately 55º.

The reference number 43g stands for an outer shell, which can be made of polyamide 11.

The flexible pipe shown in Fig. 8 makes it possible to withstand the internal pressure of the fluid, to control the ground effect without the addition of a pressure-resistant reinforcement, as set out in the present description.

According to a variant shown in Fig. 8, the flexible tube can have an interlocked inner carcass with at least one elongate interlockable element, optionally of "T" profile.

The fact that the inner track 41a is interlocked is interesting, particularly as regards the mechanical behaviour of the tube 40, in particular due to the limited axial play and the rounded shapes 43 and 44 of the edges of the profiles in contact with the tube 40. The rounded shapes appear in the straight cross-sections of the profiles, see in particular Figs. 5 and 7. If the flexible tube according to the invention comprises a compression-resistant reinforcement and a tensile-resistant reinforcement the latter may comprise a plurality of elongate elements wound at an angle of less than 55º, for example 25º or 30º, relative to the axis of the flexible pipe, when the pressure-resistant reinforcing reinforcement has at least one elongate element wound at an increased angle relative to the axis of the flexible pipe, and in particular greater than 80 to 85º.

The scope of the invention is not exceeded if the pairs of webs of one and the same reinforcement do not have symmetrical angles with respect to the axis of the flexible tube.

Thus, the tensile reinforcement according to the invention may comprise a pair of sheets wound at angles of A1 and A2 respectively, viewed on either side of the axis of the flexible tube. The determination of A1 and A2 may be apparent in particular from the older FR-2 374 580. For example, A1 may be adjacent 30 and A2 adjacent 70°, as shown in Fig. 9.

Other configurations are possible and one can choose angles of A1 equal to 54º and A2 equal to 56º.

It is not outside the scope of the invention if the "T" profile(s) do not comprise a hooking-type element. If the arms of the "T" have a rectangular shape, thus without hooking means, and once inserted on the flexible tube, the feet of the "T" are oriented in the same direction, a complementary rectangular wire can be used to occupy the space separating the axially consecutive feet of the "T".

Claims (29)

1. Flexible reinforced pipe with at least one elongate, helically wound reinforcing element, characterized in that this elongate element has a cross-section or profile which has a "T" shape. 2. Pipe according to claim 1, characterized in that the elongated element is metallic. 3. Pipe according to claim 1 or 2, characterized in that at least one edge of said elongated element has a shape designed to cooperate with a complementary shape to create an interlock. 4. Pipe according to one of the preceding claims, characterized in that it comprises 2 elongated elements, each having a "T"-shaped cross-section, these elements being wound helically in the same direction, the first having its part with the foot of the "T" corresponding to the cross-section directed towards the axis of the pipe and its part similar to the second element directed in the opposite direction. 5. Pipe according to claim 3, characterized in that this complementary shape is supported by the edge of an elongated element with a cross-section of "U" shape. 6. Pipe according to claim 5, characterized in that this elongated element, which has a cross-section in a "U" shape, is arranged such that the legs of the "U" are directed towards the axis of the pipe. 7. Pipe according to claim 4, characterized in that these first and second elongated elements are cross-sections having the same dimension. 8. Pipe according to one of claims 4 or 7, characterized in that the first elongate element has a modulus of elasticity which is lower than that of the second element. 9. Pipe according to one of claims 4 or 7, characterized in that the first and second elongate elements have the same modulus of elasticity. 10. Pipe according to claim 4, characterized in that the width of this part of the first element corresponding to the foot of the "T" is greater than the width of the similar part of the second element. 11. Pipe according to one of the preceding claims, characterized in that it comprises at least one elongated element made of steel with a "T" profile. 12. Pipe according to one of claims 1 to 10, characterized in that it comprises at least one elongated reinforcing element made of aluminum with a profile in "T" shape. 13. Pipe according to claim 1, characterized in that the ratio of the length (l) of the leg of the "T" to its height (e) is between 0.5 and 1 and advantageously between 0.66 and 1. 14. Pipe according to one of claims 1 or 13, characterized in that the ratio of the width of the foot (P) to the length of the leg (l) is between 1 and 3. 15. Pipe according to one of claims 1, 13 and 14, characterized in that the ratio between the width of the foot (P) and the height of the "T" (e) is between 0.66 and 3. 16. Pipe according to one of claims 1, 13-15, characterized in that the ratio between the width (l) to the height (E) of the "T" is between 1.66 and 5. 17. Pipe according to one of claims 1 and 13-16, characterized in that the ratio between the height (h) of an arm to the height "T" (e) is between 0.66 and 0.83. 18. Pipe according to one of claims 2 and 13-17, characterized in that the ratio between the height of a projection of the arm (C) to the height (e) of the "T" is between 0.16 and 0.66 and advantageously close to 0.33. 19. Pipe according to one of claims 4 and 13-18, characterized in that the ratio of the radial play between two "T"s placed head to foot into one another to the width of the "T" is between 2% and 10%. 20. Pipe according to one of the preceding claims, characterized in that it comprises an internal pressure-resistant reinforcement or bulge, or curvature, formed by at least one elongated element with a profile in a "T" shape. 21. Pipe according to one of the preceding claims, characterized in that it comprises an external pressure-resistant inner carcass formed by at least one elongated element with a "T"-shaped profile. 22. Pipe according to one of claims 5 or 6, characterized in that this elongated element with a cross section in the shape of a "U" consists of plastic, in particular plastic. 23. Pipe according to one of claims 5 or 6, characterized in that said elongated element, which has a cross-section of "U" shape, is made of metal. 24. Pipe according to claim 20, characterized in that this "T" profile has a reinforcement angle which is substantially greater than 80º, and preferably 85º, with respect to the axis of the flexible pipe. 25. Pipe according to one of the preceding claims with at least one reinforcing sheet, characterized in that it comprises an inner sealing sleeve which bears against this sheet or inner sheet and in that this inner sheet comprises a plurality of elongate elements with a profile of "T" shape, this inner sheet comprising axial hooking means. 26. Pipe according to claim 25, characterized in that it comprises several reinforcing webs and that only this inner web comprises axial hooking means. 27. Pipe according to one of claims 25 and 26, characterized in that it comprises two reinforcing sheets, one of which corresponds to said inner sheet, that said elongated elements of said sheet are wound at a first angle in a first direction relative to the axis of the pipe and that the elongated elements of the second sheet are wound at a second angle of opposite direction and that one of said angles is greater than or substantially equal to 55º and the other is less than and/or substantially equal to 55º 28. Pipe according to one of claims 25 to 26, characterized in that it comprises 2 pairs of webs, one of these webs corresponding to this inner web, each of the webs comprising one and the same pair of elongate reinforcing elements wound at equal angles but in opposite directions, and in that this angle of one of these pairs is greater than or substantially equal to 55º and in that this angle of the other pair is less than or substantially equal to 55º. 29. Wire, thread or reinforcing element of any shape suitable for the manufacture of reinforced flexible pipes, characterized in that said wire has a "T"-shaped profile and that the material and/or the geometry of the profile of said wire corresponds to that described in any of claims 1, 2, 3 or 11-19.