ES2351548T3 - HOSE CONNECTOR. - Google Patents

Abstract

End piece (200) for finishing one end of a hose (10) comprising a tubular body (12) of flexible material disposed between inner and outer fasteners (22, 24), the end piece comprising an inner element (202 ) adapted to be arranged at least partially inside the hose; a sealing element (204, 206) adapted to seal at least part of the tubular body completely around the circumference between the sealing element and the inner element; and separate load transfer means (208, 210, 212) adapted to transfer the axial loads applied to the hose around the sealing element in order to reduce, or eliminate, the axial load in the hose between the sealing element and the inner element, characterized in that the sealing element comprises an inner sealing ring (204) and an outer split ring (206) that can be tightened in order to force the coupling of the sealing ring with the tubular body and the inner element.

Description

The present invention relates to a hose, and more particularly it relates to a hose having an improved axial resistance. The invention especially relates to a hose that can be used in cryogenic conditions. The invention also relates to an end piece for a hose and a method of manufacturing a hose.

Typical hose applications include pumping fluids from a pressurized fluid reservoir. Examples include the supply of oils for domestic heating or LPG (liquefied petroleum gases) to a boiler; the transport of oil fluids and / or gases produced from a fixed or floating production platform to a ship's cargo hold, or from a ship's cargo hold to a ground-based storage unit; the distribution of fuel to race cars, especially during refueling in Formula 1; and the transport of corrosive fluids, such as sulfuric acid.

The use of a hose in the transport of fluids, such as liquefied gases at low temperature, is well known. Said hose is commonly used to transport gases such as liquefied natural gas (LNG) and liquefied propane gas (LPG).

In order for the hose to be sufficiently flexible, any given length must be at least partially constructed of flexible materials, that is, non-rigid materials.

The structure of said hose generally comprises a tubular body of flexible material disposed between inner and outer helically wound retaining wires. It is common for the two wires to be wound in the same step, but have a half-step offset in their winding. The tubular body usually comprises inner and outer layers with a hermetic intermediate layer. The inner and outer layers provide the structure with the resistance to transport the fluid therein. Usually, the inner and outer layers of the tubular body comprise layers of a fabric formed of a polyester such as polyethylene terephthalate. The hermetic intermediate layer provides tightness to prevent fluid from entering the hose and usually consists of a polymeric film.

The retention wires are usually applied under tension around the inner and outer surfaces of the tubular body. The retaining wires mainly serve to preserve the geometric shape of the tubular body. In addition, the outer wire can also serve to prevent excessive tangential deformation of the hose when subjected to high pressure. The inner and outer wires can also serve to prevent the hose from being crushed.

A hose of the present general type is described in European Patent Publication No. 0076540A1. The hose described herein comprises an intermediate layer of biaxially oriented polypropylene, which is said to increase the capacity of the hose to resist breakage caused by repeated bending.

Another hose is described in GB-2223817A. The hose described in said publication consists of a composite hose comprising an inner helical metal core, a plurality of fiber layers and plastic films rolled to the core, at least one layer of fiberglass fabric and at least one layer of Aluminum foil arranged adjacent to each other and rolled over plastic materials, and an outer helical metal matrix. Said hose is supposed to be suitable for transporting flammable fuels and oils.

Another hose is described in GB-1034956A. The hose described in said application consists of an electric hose or conduit, that is, it is intended to hold electric cables instead of transporting fluids. As a result, the considerations involved in the design of said hose are completely different from those described in EP-0076540A1 and GB-2223817A. The hose described in GB-1034956A comprises:

(i)

a helically wound wire internally arranged;

(ii)

an extruded neoprene hose that surrounds the inner wire;

(iii) a braided metal reinforcement surrounding the neoprene tube;

(iv)

a nylon cord arranged helically to the reinforcement;

(v)

a canvas that wraps the nylon rope and the reinforcement; Y

(saw)

a helically wound outer wire arranged around the canvas wrap.

The braided metal reinforcement is arranged so that it follows the convolutions of the inner wire by temporarily winding another wire around the reinforcement during the manufacture of the hose.

GB323352 discloses a tube coupling for use with an externally protected flexible hose.

Various hose applications require the hose to be supported along its length. This applies especially to the transport of the liquids and / or gases produced mentioned above. Without additional support, conventional hoses often cannot support their own weight or the weight of the fluid contained therein.

The present invention also relates to an improvement in the termination of the ends of the hose.

According to one aspect of the invention, an end piece for a hose is provided, as defined in claim 1.

According to another aspect of the invention, a hose is provided that incorporates the end piece, as defined in claim 12.

According to another aspect of the invention, a method is provided for manufacturing a hose incorporating the end piece, as defined in claim 15.

Other features of the invention will be defined in the dependent claims.

Other preferred features of the hose incorporating the end piece will be described below. The hose preferably comprises a tubular body of flexible material disposed between inner and outer fasteners, the hose further comprising axial reinforcement means adapted to reduce deformation of the tubular body when the tubular body is subjected to axial tension, and the means axial reinforcement are further adapted to exert a radial force inwards at least in part of the tubular body when the axial reinforcement means are subjected to axial tension.

In a particularly preferred embodiment, the rupture deformation of the tubular body and the axial resistance system is between 1 and 10%. More preferably the deformation at break greater than 5% at room temperature and at cryogenic temperatures.

By such arrangement, the axial resistance system improves the ability of the hose to cope with axial stresses, while contributing to the structural integrity of the hose during axial tension by pressing against at least a part of the tubular body . In addition, the materials of the tubular body and the axial resistance system are advantageously compatible so that each of them works in a similar way when they are in operation, so that not a single component is subjected to excessive stresses and stresses. This means that the materials of the tubular body and axial resistance system respond in a similar way to the stress. A pressure effort (for a cylindrical component) of at least 3% is generally required for the type of hose applications that are primarily provided for by the present invention. Although the sliding between layers and the resistance of the helically oriented components will justify part of said sliding, there will still be an effort resulting from the order of 1% that will act on the structural components of the hose wall. This is comparable to a normal strain stress of 0.2% for metals.

It is particularly preferred that the axial resistance system comprises a non-metallic material, especially plastic materials - the suitable materials are analyzed in detail later. This is because metallic materials rarely have the desired stress characteristics.

It is preferred that the tubular body and axial resistance system comprise the same material, more preferably ultra high molecular weight polyethylene (UHMWPE), as described in more detail below.

The tubular body preferably comprises a reinforcing layer and at least one airtight layer. More preferably there are at least two reinforcing layers with the hermetic layer interposed therebetween.

Preferably, another reinforcing layer is provided between the fastener and the axial resistance means.

The final resistance of the reinforcing layer (s) is preferably between 100 and 700 kN for a hose 8 '' (200 mm) in diameter. It is intended that the flexural stress in the breakage of the reinforcement layer (s) is between 2% and 15%. Preferably, the other reinforcement layer (s) comprises the same material as the axial resistance system, more preferably UHMWPE.

Preferably, the axial resistance system comprises a generally tubular liner consisting of a sheet of material provided with a tubular shape, so that the liner can maintain the integrity of its tubular shape when subjected to axial tension. The hose may be provided with two or more tubular linings in order to further improve the operation of the hose when subjected to axial tension.

In a particularly advantageous embodiment, the axial resistance system is provided in the form of a generally tubular braid. Here the term "braid" refers to a material that is constituted by two or more fibers or strands that have been interwoven to form an elongated structure. A characteristic of the braid is that it can be lengthened when subjected to axial tension. Another feature of the braid is that, when provided in a tubular shape, its diameter will be reduced when the braid is subjected to axial tension. Thus, by providing a tubular braid around the tubular body, or inside the structure of the tubular body, the braid will exert a radial force inwardly on at least a part of the tubular body when subjected to axial tension.

It is preferred that the entire tubular liner be provided in the form of a braid. However, it is possible that only one or more parts of the length of the tubular liner are provided in the form of a braid.

It is also preferred that the braid extends around the entire circumference of the tubular liner. However, it is possible that only one or more parts of the circumference of the tubular liner are provided in the form of a braid.

The braid can be provided in a biaxial form (i.e., in which the braid comprises only two interwoven fibers or strands) or in a triaxial form (i.e., in which fibers or strands that extend longitudinally are also found in order to increase axial resistance).

Although it is preferred to provide axial reinforcement means in the form of a braid, it can be provided in other ways that meet the functional requirements specified above. Therefore, the axial reinforcement means may be provided as a suitable arrangement of wound ropes or cords.

helically around the tubular body.

The materials for the construction of the hose must be selected so that they allow the hose to work in the environment for which it is intended. Therefore, it is necessary that the hose be capable of transporting pressurized fluids therethrough without loss of fluid through the walls of the hose. The hose also needs to resist repeated bending, and to resist axial stresses caused by the combination of hose weight and fluid. Also, if the hose is intended to be used to transport cryogenic fluids, the materials must be able to operate at extremely cold temperatures without any significant decrease in their performance.

The main purpose of each reinforcement layer is to resist the tangential stresses to which the hose is subjected during the transport of fluids through it. Therefore, any reinforcement layer that has the required degree of flexibility, and that can withstand the necessary stresses, will be suitable. Also, if the hose is intended to transport cryogenic fluids, the reinforcement layer or each of them must be able to withstand cryogenic temperatures.

It is preferred that the reinforcement layer or each of them comprise a sheet of material that has been wound in a tubular shape by winding the sheet material in a helical manner. This means that the reinforcement layer or each of them does not have much resistance to axial tension, so that the application of an axial force will tend to separate the windings. The reinforcing layer or each of them may comprise a single continuous layer of sheet material, or it may comprise two or more individual continuous layers of sheet material. However, more commonly (and depending on the length of the hose) the layer of sheet material or each of them will comprise a plurality of separate lengths of sheet material arranged along the length of the hose.

In a preferred embodiment, each reinforcing layer comprises a fabric, more preferably a flat fabric. The reinforcement layer or each of them can be made of natural or synthetic material. The reinforcing layer or each of them comprises a synthetic polymer, such as a polyester, a polyamide or a polyolefin. The synthetic polymer can be provided in the form of fibers, or yarn, from which the fabric has been created.

When the reinforcement layer or each of them comprises a polyester, preferably this is polyethylene terephthalate.

When the reinforcement layer or each of them comprises a polyamide, it may be an aliphatic polyamide, such as nylon, or it may be an aromatic polyamide, such as an aramid compound. For example, the reinforcement layer or each of them may be a poly (p-phenylenterphthalamide) such as KEVLAR (registered trademark).

When the reinforcement layer or each of them comprises a polyolefin, it can be a homopolymer of polyethylene, polypropylene or polybutylene, or a copolymer or terpolymer thereof, and is preferably oriented in a monoaxial or biaxial manner, and more preferably polyethylene be a high molecular weight polyethylene,

especially UHMWPE.

The UHMWPE used in the present invention will generally have an average molecular weight greater than 400,000, usually greater than 800,000 and usually greater than 1,000,000. The average molecular weight will usually not exceed 15,000,000. The UHMWPE is preferably characterized by a molecular weight between approximately 1,000,000 and 6,000,000. The most useful UHMWPE in the present invention is very oriented and usually stretches at least 2 to 5 times in one direction and at least 10 to 15 times in the other direction.

The most useful UHMWPE in the present invention will generally have a parallel orientation greater than 80%, more usually greater than 90%, and preferably greater than 95%. The crystallinity will generally be greater than 50%, more usually greater than 70%. Crystallinity up to 85-90% is possible.

The UHMWPE is described, for example, in US-A-4344908, US-A-4411845, US-A-4422993, US-A-4430383, US-A-4436689, EP-A-183285, EP-A- 0438831, and EP-A-0215507.

It is particularly advantageous that the reinforcement layer or each of them comprises a very oriented UHMWPE, such as that available in DSM High Performance Fibers BV (a Dutch company) under the trade name of DYNEEMA, or is available in the US. Corporation AlliedSignal Inc. with the trade name of SPECTRA.

Additional details about DYNEEMA are disclosed in a business brochure entitled "DYNEEMA;" the top performance in fibers; properties and application "published by DSM High Performance Fibers BV, edition 02/98. Additional details about SPECTRA in a commercial brochure entitled "Spectra Performance Materials" edited by AlliedSignal Inc., 5/96 edition. These materials have been available since the 1980s.

In the preferred embodiment, the reinforcement layer or each of them comprises a flat fabric formed by weft and twisted fibers. It has been found that this is particularly advantageous if the reinforcement layer or each of them is arranged such that the direction of twisting of the fabric is arranged at an angle less than 20 ° in relation to the axial direction of the hose; it is also preferred that said angle is greater than 5 °. In the preferred embodiment, the reinforcement layer or each of them is arranged so that the twist direction of the fabric is at an angle between 10 ° and 20 °, more preferably about 15 °, with the axial direction of the hose.

The purpose of the hermetic layer is mainly to prevent the loss of fluids transported through the tubular body. Therefore, any hermetic layer that presents the required degree of flexibility and that can provide the intended sealing function, will be adequate. In addition, if the hose is intended to transport cryogenic fluids, the hermetic layer must be able to withstand cryogenic temperatures.

The airtight layer may comprise the same basic materials as the reinforcement layer or each of them. Alternatively, the hermetic layer may comprise a fluoropolymer, such as polytetrafluoroethylene (PFTE); a fluorinated copolymer of ethylene and propylene, such as the copolymer of hexafluoropropylene and tetrafluoroethylene (tetrafluoroethylene-perfluoropropylene) available from DuPont Fluoroproducts under the trade name Teflon FEP; or a fluorinated hydrocarbon - perfluoroalkoxide available from DuPont Fluoroproducts under the trade name Teflon PFA. Such films can be created by extrusion or blow.

It is preferred that the airtight layer comprises a layer of material that has been tubularly wound when the sheet material is wound helically. As in the case of the reinforcement layers, this means that the hermetic layer or each one of them does not have much resistance to axial tension, so that the axial force will tend to separate the windings. The airtight layer may comprise a single continuous layer of the sheet material, or it may comprise two or more individual continuous layers of the sheet material. However, more commonly (and depending on the length of the hose) the layer of sheet material or each of them will comprise a plurality of separate lengths of sheet material arranged along the length of the hose. If so intended, the hermetic layer may comprise one or more heat-shrinkable covers (i.e., tubular) that are disposed on the inner reinforcing layer.

It is preferred that the hermetic layer comprises a plurality of superimposed layers of film. It will preferably have at least 2 layers, more preferably at least 5 layers and even more preferably at least 10 layers. In practice, the airtight layer may comprise 20, 30, 40, 50 or more layers of film. The upper limit of the number of layers depends on the overall size of the hose, but it is unlikely that more than 100 layers will be required. Usually, 50 layers, at most, will be sufficient. The thickness of each layer of film will usually be between 50 and 100 micrometers.

In a preferred embodiment, the hermetic layer also comprises at least one layer constituted partially or completely by a metal or a metal oxide. The metal or metal oxide layer may be a metal or metal oxide film layer, or a metal oxide film or metal film coated with a polymer, or a polymerized metal film with a metal or metal oxide.

Of course, more than one hermetic layer will be provided.

A particularly preferred embodiment of the airtight layer is described below.

The axial resistance system can also be formed of the same material as the reinforcement layer or each of them. Therefore, it will be clear that the axial resistance system, the reinforcement layer or each of them and the hermetic layer can all be formed by the same basic compound. However, the shape of the compound must be different to provide the required function, that is, the axial resistance system provides an axial reinforcement function, reinforcement layer or each of them provides reinforcement against tangential stresses, and the Airtight layer provides a sealing function. It has been found that UHMWPE materials are the most suitable, particularly DYNEEMA and SPECTRA products. It has also been discovered that such materials exhibit good performance in cryogenic conditions. The preferred parameters of the UHMWPE (molecular weight range, etc.) discussed above in relation to the reinforcement layers are also suitable for the axial resistance system. In this regard it should be noted, however, that the UHMWPE parameters used in the axial resistance system need not be the same as the UHMWPE parameters used in the reinforcement layers.

It is possible that the axial resistance system is provided within the layers of the tubular body. However, it is preferred that the axial resistance system be disposed between the tubular body and the outer fastener. In another preferred embodiment, the axial resistance system is provided inside the layers of the tubular body and another axial resistance system is also provided between the tubular body and the outer fastener.

When the hose is intended for cryogenic applications, it is desirable to provide insulation above the tubular body. The insulation can be provided between the outer wire and the tubular reinforcement and / or on the outside of the outer wire. The insulation may comprise materials commonly used to provide the insulation of cryogenic equipment, such as a synthetic spongy material. It is preferred that the axial resistance system is also provided around the insulating layer in order to compress the insulating layers and maintain their structural integrity. The axial resistance system around the insulating layer is preferably provided in addition to the axial resistance system that is located between the external fastener and the tubular body. A particularly suitable form of insulation is described in more detail below.

Therefore, the hose according to the invention may further comprise an insulating layer. The hose may further comprise a hardened resin matrix arranged around the outer wire, the outer wire being partially embedded in the resin matrix to restrict the relative movement between the outer wire and the rest of the hose. The uncured resin that forms the resin matrix can be of a material, such as a polyurethane, which can be applied to the tubular element in liquid form.

In one embodiment, the hose further comprises an insulating layer comprising a fabric formed of basalt fibers. A compression layer may be provided around the basalt tissue, which serves to compress the basalt tissue. The compression layer may comprise an ultra high molecular weight polyethylene.

In one embodiment, the hose further comprises a layer of plastic material around the tubular element, the gas material containing gas bubbles. The plastic material can be polyurethane. The plastic material can be applied to the tubular body by spraying the plastic material, in liquid form, over the surface of the tubular body, subsequently allowing it to harden. Gas bubbles can be incorporated by injecting the gas into the plastic material, before spraying, while still in liquid form. The hose may also comprise an additional layer of plastic material, which does not contain a substantial amount of gas bubbles, disposed above the plastic material containing gas; This additional layer of plastic material can be polyurethane.

In one embodiment, the total specific gravity of the hose less than 0.8.

The hose may be provided in addition to an end piece as described in greater detail below.

It is possible to remove the hose from the mandrel before placing the end piece in it. Alternatively, the end piece can be arranged inside the rest of the hose by sliding the inner mandrel along it to one end of the hose, then fixing the rest of the hose to the end piece while the piece end and the rest of the hose remain in the mandrel.

Naturally, a separate end piece can be applied to each end of the hose.

In the embodiments of the invention described above, each fastener comprises a helically wound wire. The propellers of the wires are normally arranged in such a way that they move each other a distance that corresponds to a half-step length of the propellers. The purpose of the wires is to firmly hold the tubular body between them in order to keep the tubular body layers intact and provide structural integrity to the hose. The inner and outer wires may be composed, for example, of low carbon steel, austenitic stainless steel or aluminum. If desired, the wires can be galvanized or coated with a polymer.

It will be appreciated that although the wires that form the clamping elements can have considerable tractional resistance, the arrangement of the spiral wires means that the clamping elements can deform when subjected to a relatively small axial tension. Any significant deformation in the spirals will quickly destroy the structural integrity of the hose.

The hose incorporating the end piece, according to the invention, can be provided for use in a wide variety of conditions, such as temperatures above 100 ° C, temperatures between 0 ° C and 100 ° C and temperatures below 0 ° C. By choosing the appropriate material, the hose can be used at temperatures below -20 ° C, below -50 ° C or even below -100 ° C. For example, for the transport of LNG, the hose may have to operate at temperatures up to -170 ° C or even lower. In addition, it is also contemplated that the hose can be used to transport liquid oxygen (p. E -183 ° C) or liquid nitrogen (p. E. -196 ° C), in which case it may be necessary for the hose to operate at temperatures of -200 ° C or lower.

The hose incorporating the end piece according to the invention can be provided for use in a wide variety of conditions, such as at temperatures. Normally, the inner diameter of the hose will be between approximately 2 inches (51 mm) and approximately 24 inches (610 mm), more usually between approximately 8 inches (203 mm) and approximately 16 inches (406 mm). In general, the operating pressure of the hose will be between approximately 500 kPa of gauge pressure and about 2000 kPa of gauge pressure, or possibly up to about 2500 kPa of gauge pressure. These pressures refer to the operating pressure of the hose, not the breaking pressure (which may be several times higher). The volumetric flow rate depends on the fluid medium, the pressure and the inside diameter. The flow rates between 1000 m3 / h and 12000 m3 / h are normal.

The hose incorporating the end piece according to the invention can also be provided for use with corrosive materials, such as strong acids.

Reference is now made to the accompanying drawings in which:

Figure 1 is a schematic diagram illustrating the main tensions to which the hose incorporating the end piece according to the invention is subjected when in operation;

Figure 2 is a schematic cross-sectional view of a hose incorporating an end piece (not shown) according to the invention;

Figure 3 is a sectional view illustrating the arrangement of a reinforcement layer of the hose according to the invention;

Figure 4A is a sectional view illustrating the arrangement of a tubular axial reinforcement sleeve of the hose according to the invention, the axial reinforcement sleeve being in the rest position;

Figure 4B is a sectional view illustrating the arrangement of a tubular axial reinforcement sleeve of the hose according to the invention, the axial reinforcement sleeve being in tension position;

Figures 5A, 5B, 5C and 5D illustrate four applications of the hose according to the present invention;

Figure 6 is a cross-sectional view illustrating the hermetic layer of a hose according to the invention;

Figure 7 is a cross-sectional view illustrating the insulating layer of the hose of Figure 2 in greater detail; Y

Figure 8 is a schematic cross section of the terminal connector of a hose according to the invention.

Figure 1 illustrates the tensions to which hose H is normally subjected during use. The tangential stress is indicated by the arrows HS and consists of the tension acting tangentially to the periphery of the hose H. The axial tension is indicated by the arrows AS and consists of the tension acting axially along the length of the hose H. The bending tension is designated as FS and consists of the tension that acts transversely to the longitudinal axis of the hose H when it flexes. The torsional tension is designated as TS and consists of the torsional tension acting on the longitudinal axis of the hose. The crushing stress is designated as CS and occurs when loads are applied radially to the outside of hose H.

The tangential stress HS originates through the pressure of the fluid in the hose

H. The axial stress AS is caused by the pressure of the fluid in the hose and also by the combination of the weight of the fluid in the hose H and by the weight of the hose itself H. The flexural stress FS is produced by the need to bend the hose H in order to dispose it properly and by the movement of the hose H during use. The torsional stress TS is caused by the twisting of the hose. In the prior art, the hose can generally withstand the tangential stresses HS, the flexural stresses FS and the torsional stresses TS, but have a lower capacity to resist the axial stresses AS. For this reason, when the hoses of the prior art were subjected to large axial stresses AS they generally had to rest in order to minimize the axial stresses AS.

The problem of axial stress resistance AS has been solved in the present invention. In Figure 2 a hose according to the invention is generally designated as 10. In order to improve clarity the winding of the various layers in Figure 2, and in the other Figures, is not illustrated.

The hose 10 comprises a tubular body 12 comprising an inner reinforcing layer 14, an outer reinforcing layer 16 and an airtight layer 18 sandwiched between layers 14 and 16. A generally tubular sheath 20, which provides axial reinforcement, is disposed around the outer surface of the outer reinforcing layer 16.

The tubular body 12 and the tubular sheath 20 are disposed between a helically wound inner wire 22 and a helically wound outer wire 24. The inner and outer wires 22 and 24 are arranged so that they move each other a distance corresponding to a length Half step of spiral propellers.

An insulating layer 26 is disposed around the outer wire 24. The insulating layer may be composed of a conventional insulating material, such as a plastic foam or it may consist of a material described later in relation to Figure 7.

The reinforcing layers 14 and 16 comprise flat fabrics of a synthetic material, such as UHMWPE or aramid fibers. Figure 3 illustrates the inner reinforcing layer 14, in which it is clearly seen how the inner reinforcing layer 14 comprises the fibers 14a arranged in the winding direction W, and the fibers 14b arranged in the warp direction F. Figure 3 only illustrates layer 14 in order to increase clarity. It has been unexpectedly discovered that the axial resistance of the hose 10 can be increased by arranging the inner reinforcing layer 14 so that the winding direction W is at a low angle, less than 20 ° and usually approximately 15 ° in relation to the longitudinal axis of the hose 10. Said angle is indicated by the symbol α of Figure 3. The structure and orientation of the outer reinforcing layer 16 is substantially identical to the inner reinforcing layer 14; the angle α of the outer reinforcement layer 16 may be the same, or different, than the angle α of the inner reinforcement layer 14.

The hermetic layer 18 comprises a plurality of layers of plastic film that are wound around the outer surface of the inner reinforcing layer 14 in order to provide a fluid tight seal between the inner and outer reinforcing layers 14 and

16.

The hose 10 further comprises a reinforcing layer 21 disposed between the sheath 20 and the wires 24. The reinforcing layer 21 may have characteristics similar to those of the sheath 20 and the tubular body 12.

The tubular sheath 20 is composed of two sets of fibers 20a and 20b that are braided to form a tubular braid. This is illustrated in Figures 4A and 4B - in said Figures only the tubular sheath 20 is illustrated in order to increase clarity. Spaces 28 are found between the fiber assemblies 20a and 20b, so that when the tubular sheath 20 is subjected to axial tension the fibers 20a and 20b can contract by moving towards the spaces 28. This acts in a way that attempts to reduce the diameter of the tubular sheath 20, which causes tension around the tubular body 12, thereby increasing the structural integrity and breaking pressure of the hose 10. Figure 4B illustrates the tubular sheath 20 in tension position.

The hermetic layer 18 is illustrated in greater detail in Figure 6. The supply of the hermetic layer 18 increases the resistance of the hose to the flexural stress FS and the tangential stress HS.

As illustrated in Figure 6, the airtight layer 18 comprises a plurality of layers 18a of a film composed of a first polymer (such as a highly oriented UHMWPE) interspersed with a plurality of layers 18b of a film composed of a second polymer (such as PFTE or FEP), the two polymers presenting a different stiffness. Layers 18a and 18b have been wound around the surface of the inner reinforcing layer 14 in order to provide a fluid tight seal between the inner and outer reinforcing layers 14 and 16. As mentioned above, layers 18a and 18b must not necessarily be arranged alternately. For example, all layers 18a could be arranged together and all layers 18b could be arranged together.

The insulating layer 26 is shown in greater detail in Figure 7. The main function of the insulating layer is to increase the resistance of the hose to the bending stress FS and to insulate the hose.

The insulating layer 26 comprises an inner layer 26a which is composed of polyurethane that has been applied by spraying, pouring or otherwise, onto the tubular body 12 and the outer wire 24. After hardening, the polyurethane layer 26a forms a matrix solid in which the outer wire 24 is embedded. This helps keep the wire 24 in a fixed position. In a preferred embodiment, the inner layer 26a is provided with bubbles inside.

The insulating layer 26 comprises a layer 26b on the layer 26a. Layer 26b comprises a fabric composed of basalt fibers. Layer 26b provides most of the insulating properties of hose 10.

The insulating layer 26 comprises a layer 26c on the layer 26b. Layer 26c comprises a UHMWPE such as DYNEEMA or SPECTRA. The purpose of layer 26c is primarily to provide resistance against tangential and flexural stresses.

The insulating layer 26 comprises a compression layer 26d. The purpose of the compression layer 26d is to compress the layer 26b, since it has been found that the insulating properties of the basaltic tissue layer 26b are greatly increased under compression. The compression layer 26d can, for example, compress a rope or a cord that is wrapped tightly around the layer 26c. Preferably, the compression layer 26d comprises an axial resistance sheath such as the sheath 20 described above.

Another polyurethane layer (not illustrated) containing gas bubbles can be disposed on layer 26d to further increase the insulating properties and buoyancy of the hose 10. Yet another polyurethane layer (not illustrated) that does not contain bubbles of gas can be disposed on the polyurethane layer containing gas. Said other polyurethane layer may additionally, or instead, be disposed within the layer 26d. It is also possible that the layer 26a itself contains the gas bubbles.

The hose 10 can be made by the following technique. In a first stage the inner wire 22 is wound around a support mandrel (not illustrated), in order to provide a helical arrangement that presents the desired passage. The diameter of the support mandrel corresponds to the desired inner diameter for the hose 10. The inner reinforcement layer 14 is then wound around the inner wire 22 and the support mandrel, so that the winding direction W is arranged at the angle desired α.

Next, a plurality of layers of plastic films 18a, 18b composing the insulating layer 18 are wound around the outer surface of the inner reinforcing layer 14. Usually, the films 18a and 18b will have a length substantially less than the length of the hose 10, so that a plurality of separate fragments of the films 18a and 18b will have to be wrapped around the inner layer 14. The films 18a and 18b are preferably arranged alternately along the thickness of the airtight layer 18. Normally Five separate layers of films 18a and 18b can be found along the thickness of the airtight layer.

Then the outer reinforcing layer 16 is wound around the hermetic layer 18, so that the winding direction W is arranged at the desired angle (which can be α or can be any other angle close to α). The tubular axial reinforcement sheath 20 is disposed above the outer part of the outer reinforcement layer 16. The additional reinforcement layer 21 is then wound around the sheath 20.

Then the outer wire 24 is wound around the additional reinforcement layer 21, in order to provide a helical arrangement that presents the desired passage. The passage of the outer wire 24 will normally be the same as the passage of the inner wire 22, and the position of the wire 24 will normally be arranged such that the turns of the wire 24 travel relative to the turns of the wire 22 a corresponding distance at a half step length; this is illustrated in Figure 2, in which the length of the passage is designated as p.

A polyurethane resin is then sprayed above the outer surface of the reinforcing layer 21 to form a resin coating above the layer 21 and the outer wire 24. The resin can then be allowed to stand to harden, to in order to form layer 26a. The resin can be aerated before hardening (usually before spraying or painting) to provide the gas bubbles therein. Then the basaltic tissue layer 26b is wound around the polyurethane layer 26a, and the UHMWPE layer 26c is wound around the layer 26b. Finally, compression layer 26d is applied over layer 26c.

The hose terminals 10 can be sealed tightly by bending the edges of a sheath inwards over an intercalated piece inside the hose

10. Said termination is generally applied once the hose 10 has been removed from the mandrel.

The hose terminals 10 can be tightly closed using the end piece 200 illustrated in Figure 8. In Figure 8, the hose 10 is not illustrated in order to increase clarity. The end piece comprises an inner tubular element 202 having a hose terminal 202a and a lower end 202b. The end piece 200 further comprises a hermetic sealing element comprising a PTFE sealing ring 204 and a split ring 206 around the PTFE sealing ring 204.

The end piece 200 further comprises load transfer means comprising an element that engages with the hose 208, a load transfer element 210 and an end element in the form of a discoid plate 212. The load transfer element comprises a discoid plate 214 and at least one load transfer bar 216. Two of the bars 216 are illustrated in Figure 2, but three or more bars 216 are possible. In each bar 216 a clamping nut 218 is arranged. The plates 212 and 214 have openings 212a and 214a respectively to accept the bars 216.

Each of the plates 212 and 214 can be a Simonplate, the element that couples with the hose 202 can be a Gedring and the split ring 206 can be an Ericring.

The plate 212 also has the openings 212b, and the lower end 202b of the inner element 202 has the openings 202c. The fastening bolts 220 extend through the openings 202b and 212b to fix the plate 212 to the lower end 202a of the inner element 202. In Figure 2, two fastening bolts 220 and their associated openings are illustrated, but it can be seen that it can be arranged a lower or higher number of fastening bolts 220.

The element that is coupled with the hose 208 is provided with an inner helical groove in the form of grooves 208a that are adapted to contain the outer wire 24 of the hose 10 therein. The inner element 202 is provided with an outer helical groove in the form of grooves 202d that are adapted to contain the inner wire 22 therein. It can be seen in Figure 2 that, in the same way as the inner and outer wires 22 and 24, the slots 208a and 202d are separated by half step length p.

The inner element 202 is provided with two circumferential projections 202e which are arranged under the airtight sealing ring 204. The projections 202e are intended to hermetically seal the tubular element 20 between the inner element 202 and the airtight sealing ring 204, and contribute to prevent the tubular element from being involuntarily displaced from its position.

The hose 10 is fixed to the end piece 200 as follows. The inner element 202 is screwed into the hose terminal 10, so that the hose 10 rests near the plate 212. The inner wire 22 is supported in the slots 202d and the outer wire 24 in the slots 208a. The inner and outer wires 22 and 24 are trimmed so that they do not extend outside the inner member 202 beyond the slots 202d and 208a. The insulation 26 is also trimmed at this point. The inner reinforcement layer 14 is also cut at this point, or at some point before the inner reinforcement layer 14 reaches the airtight sealing ring 204. This means that the tight layer 18 is directly coupled with the outer surface of the element. interior 202. The rest of the tubular body 12, however, can extend along the inner element 202 between the inner element 202 and the sealing ring

204.

Next, the element that is coupled with the hose 208 is tightened to cause it to close in the hose 10 by firmly engaging with the hose 10. Then the nuts 218 are tightened, which causes some axial tension in the hose 10, absorbing from This mode any system vibration. Said forces are transmitted from the element that is coupled with the hose 208, to the plate 214, to the bar 216, to the plate 212, and to the lower end 202b of the inner element 202. The tubular element 20 is stretched on the surface upper of the element that is coupled with the hose 208, and fixed to the projections 208b extending from the upper surface of the element that is coupled with the hose 208.

The tubular body 12 extends under the airtight sealing ring 204. Once the element that is coupled with the hose 208 and the nuts 218 has been tightened, the split ring 206 is tightened in order to increase the force applied to the tubular body 12 by the sealing ring 204.

The end piece 200 is then cooled to a low temperature with liquid nitrogen. This causes the hermetic sealing ring 204 to contract relatively more than the split ring 206, whereby the compressive force applied on the hermetic sealing ring 204 by the split ring 206 is reduced. While the split ring 206 and the Airtight sealing ring 204 is at a relatively low temperature, the split ring 206 is pressed again. The temperature is then allowed to rise to ambient conditions, whereby the compressive strength of the airtight sealing ring increases thanks to the greater expansion of the sealing ring 204 in relation to the split ring

206.

This completes the end piece of the hose 10. The element that engages with the hose 208 contributes to the closure of the hose terminal 208, and contributes by collecting the axial forces of the hose 10 around the airtight sealing ring 204. The sealing ring airtight seal 204 provides the rest of the hose seal 10.

Figures 5A to 5D illustrate three applications of the hose 10. In each of Figures 5A to 5C a floating production, storage and discharge unit (FPSO) 102 is attached to an LNG conveyor 104 via a hose 10 according to the invention . The hose 10 transports the LNG from a storage tank of the FPSO 102 to a storage tank of the LNG 104 conveyor. In Figure 5A, the hose 10 is above sea level 106. In Figure 5B, the hose 10 is submerged below sea level 106. In Figure 5C, hose 10 floats near the sea surface. In each case, the hose 10 transports the LNG without any intermediate support. In Figure 5D the LNG conveyor is attached to a ground-based storage facility 108 via hose 10.

The hose 10 can be used in many other applications apart from the applications illustrated in Figures 5A to 5C. The hose can be used in cryogenic and non-cryogenic conditions.

It will be appreciated that the invention described above can be modified within the scope of the following claims. For example, the tubular sheath 20 may be disposed on the outer part of the outer wire 24. Also, the hose 10 may comprise reinforcing layers 14, 18, hermetic layers 16 and / or additional tubular sleeves 20. One or more of the hermetic layers 18a, or even all of them, may be composed of a metal film coated by a polymer or a metallized polymeric film. Similarly, one or more of the hermetic layers 18b, or even all of them, may be composed of a metal film coated by a polymer or a metallized polymeric film.

Claims (18)

1. End piece (200) for finishing one end of a hose (10) comprising a tubular body (12) of flexible material disposed between inner and outer fasteners (22, 24), the end piece comprising an inner element (202) adapted to be disposed at least partially inside the hose; a sealing element (204, 206) adapted to seal at least part of the tubular body completely around the circumference between the sealing element and the inner element; and separate load transfer means (208, 210, 212) adapted to transfer the axial loads applied to the hose around the sealing element in order to reduce, or eliminate, the axial load in the hose between the sealing element and the inner element, characterized in that the sealing element comprises an inner sealing ring (204) and an outer split ring (206) that can be tightened in order to force the coupling of the sealing ring with the tubular body and the inner element.

2.

End piece according to claim 1, wherein the inner element is substantially cylindrical, and the sealing ring is adapted to receive the inner element inside, so that the tubular body can be tightened between the outer surface of the inner element and the inner surface of the sealing ring.

3.

End piece according to claim 1 or 2, wherein the split ring is made of stainless steel and the sealing ring is made of polytetrafluoroethylene.

Four.

End piece according to any one of claims 1 to 3, wherein the load transfer means comprise an element that engages with the hose (208), a load transmission element (210) and an end element (212) fixed to the inner element, the arrangement being such that the sealing element is disposed between the load transmission element and the end element, and that the element that is coupled with the hose and the end element are connected by the transmission element loading

5.

End piece according to claim 4, wherein the element that is coupled with the hose is adapted to engage with the hose such that at least part of the axial forces inside the hose are transferred from the hose to the element that It fits with the hose.

6.

End piece according to claim 4 or 5, wherein the load transfer element comprises a load transfer plate (214) having an opening (212b) adapted to receive the hose therethrough, the plate presenting a surface that can fit with the element that is coupled with the hose, so that loads can be transferred from the element that is coupled with the hose to the plate.

7.

End piece according to claim 6, wherein the load transfer element further comprises a load transfer bar (216) fixed between the plate and the end element for transferring the loads from the plate to the end element.

8.

End piece according to any one of claims 1 to 7, wherein the inner element has a hose terminal (202a) that is adapted to extend in the end zone of the hose, and a lower end (202b) away from the hose terminal , and the end element being arranged on one side of the sealing element, adjacent to the lower end, and the element being coupled to the hose on the other side of the sealing element adjacent to the hose terminal.

9.

End piece according to any of claims 1 to 8, wherein the sealing element is adapted to seal against the tubular body regardless of the application of axial loads between the hose and the inner element.

10.

Hose comprising a tubular body of flexible material disposed between an inner and outer wire helically wound, the tubular body serving to transport fluid through the hose and to prevent the loss of fluid through the body, characterized in that the hose further comprises a end piece according to any one of claims 1 to 8 adjusted to one of its ends.

eleven.

Hose according to claim 10, when subordinated to claim 4, wherein the element that is coupled with the hose is adapted to fix a part of the hose that is retracted above an outer part of the element that is coupled with the hose.

12.

Hose according to claim 11, further comprising axial reinforcement means in the form of a braid (20) around a tubular body, and wherein the braid is the part of the hose that is retracted above the outer part of the tubular element

13.

Hose according to claim 10, 11 or 12, wherein the tubular body extends between the inner element and the sealing element.

14.

Hose according to claim 10, 11, 12 or 13, wherein the tubular body comprises at least one reinforcing layer and at least one sealing layer.

15. Procedure for making a hose, comprising:

(to)

wind a wire around a tubular mandrel to form an inner spiral (22);

(b)

winding a sheet material around the tubular mandrel and the inner spiral to provide a tubular body formed of sheet material;

(C)

wind a wire around the tubular body to form an outer spiral; Y

(d)

remove the hose from the mandrel; characterized in that it comprises the following stages:

(and)

disposing an inner element at an open end of the hose;

(F)

fixing a load transfer means to an external surface of the hose; Y

(g)

fixing a sealing element comprising an inner sealing ring and an outer split ring to an outer surface of the tubular body, and tightening the split ring to force the sealing ring to fit with the tubular body and the inner element.

16.

Method according to claim 15, wherein the load transfer means serves to transfer axial loads applied between the hose and the inner element such that said axial loads are diverted around the sealing element to reduce or eliminate any axial load in the hose between the sealing element and the inner element, and in which in step (g) the fixing of the sealing element to the outer surface of the tubular body seals the sealing element against the tubular body regardless of the application of axial loads between the hose and the inner element.

17.

Method according to claim 15 or 16, further comprising the following stage between step (b) and (c):

(h) stretching a tubular axial reinforcement element above a free end of the mandrel, so that the mandrel extends into the axial reinforcement element, then stretching the axial reinforcement element along the mandrel so that it covers at least partially the tubular body.

18.

Method according to claim 17, wherein the axial reinforcement means are fixed by means of the load transfer means, and also comprising the following stage after step (f):

(i) folding the tubular axial reinforcement element above a part of the axial reinforcement means.