JP4897182B2 - hose - Google Patents

Description

[0001]
The present invention relates to hoses, and more particularly, to hoses with improved axial strength. The invention particularly relates to hoses that can be used in cold storage conditions. The invention also relates to an end fitting for a hose and a method of manufacturing the hose.
[0002]
A typical application of a hose involves pumping fluid from a fluid reservoir under pressure. For example, supply of household heating oil or LPG to boilers, oil fields produced from fixed or floating production platforms to ship cargo holds, or from ship cargo holds to storage units on land bases This includes the transport of liquids and / or gases, especially the refueling of the racing car during refueling in Formula One, and the transport of corrosive liquids such as sulfuric acid.
[0003]
It is well known to use hoses for the transport of liquids such as liquefied gases at low temperatures. Such hoses are commonly used to transport liquefied gases such as liquefied natural gas (LNG) and liquefied propane gas (LPG).
[0004]
In order for the hose to be sufficiently flexible, some of the given length must be at least partially composed of a soft material, i.e. a non-rigid material.
[0005]
Such hose construction generally includes a tubular body of soft material disposed between an inner and outer helically wound retaining wire. The two wires may be wound at the same pitch in the related art, or may be wound while being shifted from each other by half the pitch width. The tubular body typically includes inner and outer layers having an intermediate sealing layer. The inner and outer layers provide the structure with strength to transport the liquid therein. Conventionally, the inner and outer layers of the tubular body include a fabric layer formed from a polyester such as polyethylene terephthalate. The intermediate sealing layer provides a seal to prevent liquid from penetrating the hose and is typically a polymer film.
[0006]
The retaining wire is typically applied under tension around the inner and outer surfaces of the tubular body. The holding wire mainly serves to protect the outer shape of the tubular body. In addition, the outer wire may serve to suppress hoop hoop deformation under high pressure. The inner and outer wires may also serve to resist hose collapse.
[0007]
This general type of hose is described in European Patent No. 0076540A1. The hose described in this specification includes a biaxially oriented polypropylene intermediate layer, which is said to improve the performance of the hose to withstand fatigue due to repeated bending.
[0008]
Another hose is described in GB-2223817A. The hose described in this publication has one inner spiral metal core, multiple layers of fiber and film of plastic material wrapped around the core, arranged adjacent to each other and wound around the plastic material. A multi-layer hose comprising at least one layer of woven glass fabric and at least one layer of aluminum foil and an outer helical metal former. This hose is said to be suitable for transporting combustible fuels and oils.
[0009]
Another hose is described in GB-1034956A. The hose described in this application is an electrical hose or conduit, i.e. intended to carry electrical wires rather than for fluid transport. As a result, the considerations included in this hose design are completely different from the considerations included in the hoses described in EP-0076540A1 and GB-2223817A. The hose described in GB-1034956A includes: That is,
(I) a spirally wound wire disposed inside,
(Ii) extruded neoprene hose surrounding the inner wire,
(Iii) a braided metal sheath surrounding the neoprene hose,
(Iv) nylon cord applied spirally to the outer cylinder,
(V) Nylon cord and canvas wrap around outer sleeve, and
(Vi) A spiral wound wire provided around the canvas packaging.
[0010]
Braided metal shells are made according to inner wire convolutions by temporarily wrapping additional wires around the shell during hose manufacture.
[0011]
Many applications of hoses require the hose to be supported along its length. This applies in particular to the transport of the liquids and / or gases produced as described above. Without additional support, conventional hoses often cannot support their own weight or the weight of the liquid contained therein.
[0012]
We have found a way to improve the load carrying capabilities of hoses, in particular of the type described in EP-0076540A1, so that this requires no support at all, or more Only a reduced need for support can be used to carry the liquid. This hose is suitable for both cold and non-cryogenic applications.
[0013]
We have also found a way to improve the sealing layer in the above type of hose.
[0014]
In the type of hose described in EP0076540A1, it is important that the wire is maintained in the correct position. Generally, the helical inner and outer wires are offset longitudinally with respect to each other by a distance equal to about half the pitch length. This sequence has been found to provide the best structural integrity. However, one of the problems with this type of hose is that repeated bending can cause the wire coil to deviate from proper alignment.
[0015]
The invention also relates to an improvement to the outer part of the hose type described above, ie the part outside the hose of the tubular body.
[0016]
The type of hose described in EP0076540A1 is usually formed by the following technique. That is, the inner wire is wound around the tubular mandrel to form the inner coil, the inner reinforcing layer is wound around the tubular mandrel and the inner coil, and the sealing layer is wound around the inner reinforcing layer. Wrap the outer reinforcement layer around the sealing layer, wrap the outer wire around the outer reinforcement layer, form the outer coil, crimp the hose end, and fix the hose to the mandrel Remove from.
[0017]
The present invention also relates to improved termination of the hose end.
[0018]
In general, the hose is provided with an axial strengthening means that allows the hose to withstand greater axial tension than previously possible without compromising the other performance of the hose.
[0019]
In a first aspect of the invention, a hose is provided that includes a tubular body of soft material disposed between inner and outer gripping members, wherein the hose is further axially oriented. Also includes an axial reinforcement means adapted to reduce deformation of the tubular body when subjected to the tension of the axial body, and the axial reinforcement means further includes an axial reinforcement means when the axial reinforcement means is subjected to axial elongation. Adapted to exert a radial inward force at least in part.
[0020]
In a particularly preferred embodiment, the breaking strain of the tubular body and the shaft reinforcing means is in the range of 1% to 10%. More preferably, the strain at break is greater than 5% at ambient temperature and cold storage temperature.
[0021]
With this arrangement, the axial reinforcement means improves the hose's performance against axial stresses, while at the same time pushing the at least part of the tubular body to ensure structural integrity of the hose while being axially extended. Can contribute. In addition, the materials of the tubular body and the shaft strengthening means are advantageously adapted so that in operation they each function in the same way, so that every component alone is subjected to excessive stress and strain. There is no. This means that the material of the tubular body and the shaft strengthening means reacts to strain as well. A bending strain of at least 3% (relative to the cylindrical component) is generally required for the type of hose application primarily envisioned by the present invention. Slipping between layers and straightening of the orientated components cause some of this deviation, but on the order of 1% acting on the structural parts of the hose wall There can also be synthetic distortion. This corresponds to the normal 0.2% yield strain in metals.
[0022]
It is particularly preferred that the shaft strengthening means is made from a non-metallic material, in particular a plastic material, suitable materials will be described in detail later. This is because metal materials are unlikely to have the desired strain characteristics.
[0023]
The tubular body and the shaft reinforcing means preferably comprise the same material, and most preferably comprise ultra high molecular weight polyethylene (UHMWPE) which will be described in further detail below.
[0024]
The tubular body preferably includes at least one reinforcing layer and at least one sealing layer. More preferably, there are at least two reinforcing layers having a sealing layer sandwiched between them.
[0025]
Preferably, a further reinforcing layer is provided between the outer gripping member and the shaft reinforcing means.
[0026]
The breaking strength of the reinforcing layer is preferably between 100 kN and 700 kN for a 8 inch (200 mm) diameter hose. The breaking bending strain of the reinforcing layer is preferably in the range of 2% to 15%. Desirably, the further reinforcing layer is most preferably the same material as the axial reinforcement means, and more preferably UHMWPE.
[0027]
The shaft reinforcing means preferably includes a general tubular outer cylinder formed from a sheet of tubular shaped material so that the outer cylinder is in its tubular shape when subjected to axial tension. Can maintain the integrity. The hose may be provided with two or more tubular outer tubes to further improve the hose's throughput under axial tension.
[0028]
In a particularly advantageous embodiment, the shaft strengthening means is provided in the form of a generally tubular braid. In this specification, the term “braid” refers to a material formed from two or more fibers or strands intertwined to form an elongated structure. A characteristic of braids is that they can stretch when subjected to axial tension. A further feature of the braid is that given its tubular form, its diameter can decrease when the braid is subjected to axial tension. Thus, by providing a tubular braid around or within the structure of the tubular body, the braid can be attached to at least a portion of the tubular body when subjected to axial tension. Can exert a radial inward force.
[0029]
All tubular outer cylinders are preferably provided in the form of braids. However, it is also possible that only one part or more of the length of the tubular outer cylinder is provided in the form of a braid.
[0030]
Furthermore, the braid preferably extends all the way around the outer periphery of the tubular outer cylinder. However, it is also possible that only a part of the outer periphery of the tubular outer cylinder is provided in the form of a braid.
[0031]
The braid can be biaxial (ie, the braid is formed from only two intertwined fibers or strands), or triaxial (ie, due to increased axial strength). , There are fibers or strands that extend in the longitudinal direction).
[0032]
Although it is preferred to provide the shaft strengthening means in the form of a braid, it may be provided in other forms that meet the functional requirements described above. Thus, the shaft strengthening means can also be provided as a suitable arrangement of cords or ropes spirally wound around the tubular body.
[0033]
The construction material of the hose should be selected so that the hose can function in the intended environment. Thus, the hose needs to be able to transport the pressurized fluid therethrough without leakage of fluid through the hose wall. The hose also needs to withstand repeated bending and withstand axial stresses caused by the combination of the hose and fluid weight. Also, if the hose is intended to be used for transporting cold storage fluids, the material should be capable of operating at cryogenic temperatures without significantly degrading performance.
[0034]
The main purpose of the reinforcement layer or each reinforcement layer is to withstand the circumferential stresses experienced by the hose during transport of fluid therethrough. Thus, a reinforcing layer that has the required flexibility and can withstand the required stress is suitable. Also, if the hose is intended to transport cold storage fluid, the reinforcing layer or each reinforcing layer must be able to withstand cold storage.
[0035]
The reinforcing layer or each reinforcing layer is preferably formed from a sheet of material that is bent into a tubular form by winding the sheet material in a spiral. This means that the reinforcing layer or each reinforcing layer does not retain any resistance to axial tension when the axial force load tends to pull the windings apart. The reinforcing layer or each reinforcing layer may include a single continuous layer of sheet material, or may include two or more consecutive layers of sheet material. More usually, however (and also according to the length of the hose), the layer of sheet material or each layer may be formed from a plurality of divided length sheet materials arranged along the length of the hose.
[0036]
In a preferred embodiment, each reinforcing layer comprises a fabric, most preferably a woven fabric. The reinforcing layer or each reinforcing layer may be either natural or synthetic material. The reinforcing layer or each reinforcing layer is conveniently formed of a synthetic polymer such as polyester, polyamide or polyolefin. Synthetic polymers may be provided in the form of fibers or strands from which the fabric is made.
[0037]
When the reinforcing layer or each reinforcing layer comprises polyester, it is preferred that it is polyethylene terephthalate.
[0038]
When the reinforcing layer or each reinforcing layer contains a polyamide, it may be an aliphatic polyamide such as nylon or an aromatic polyamide such as an aramid compound. For example, the reinforcing layer or each reinforcing layer may be poly- (p-phenylene terephthalamide) such as Kevlar (registered trademark).
[0039]
When the reinforcing layer or each reinforcing layer comprises a polyolefin, it can be a polyethylene, polypropylene or polybutylene homopolymer, or a copolymer or terpolymer thereof, preferably uniaxially or biaxially oriented. More preferably, the polyolefin is polyethylene, and most preferably the polyethylene is high molecular weight polyethylene, especially UHMWPE.
[0040]
The UHMWPE used in the present invention may generally have an average molecular weight greater than 400,000, typically greater than 800,000, usually greater than 1,000,000. The average molecular weight will usually not exceed about 15,000,000. UHMWPE is preferably characterized by a molecular weight of about 1,000,000 to 6,000,000. The UHMWPE most useful in the present invention is highly oriented and can usually be stretched at least 2-5 times in one particular direction and at least 10-15 times in the other direction.
[0041]
The most useful UHMWPE in the present invention generally has a parallel orientation of greater than 80%, more usually greater than 90%, and preferably greater than 95%. The degree of crystallinity is generally greater than 50%, more usually greater than 70%. Crystallinity ranging from 85 to 90% is possible.
[0042]
UHMWPE is, for example, US-A-4344908, US-A-4411845, US-A-4422993, US-A-4430383, US-A-4436289, EP-A-183285, EP-A-0388831, and EP- A-0215507.
[0043]
Particularly useful is that the reinforcing layer or each reinforcing layer is available from DSM High Performance Fibers BV (Netherland Company) using the trade name DYNEEMA Or a highly oriented UHMWPE such as that available from US Corporation Allied Signal Inc. using the trade name SPECTRA.
[0044]
For more details on DYNEEMA, the product titled “DYNEEMA; the top performance in fibers; properties and applications” published 02/98 published by DSM High Performance Fiber BV It is disclosed in the pamphlet. Further details about SPECTRA are disclosed in a product brochure entitled “Spectra Performance Materials” published by Allied Signal, Inc. 5/96. These materials have been available since the 1980s.
[0045]
In a preferred embodiment, the reinforcing layer or each reinforcing layer comprises a woven fabric formed from fibers arranged in the weft and warp directions. We have found that the reinforcing layer or each reinforcing layer is particularly useful when arranged so that the warp direction of the fabric is less than 20 ° relative to the axial direction of the hose. This angle is also preferably greater than 5 °. In a preferred embodiment, the reinforcing layer or each reinforcing layer is positioned such that the warp yarn angle of the fabric is at an angle of 10 ° to 20 °, more preferably about 15 ° relative to the axial direction of the hose.
[0046]
The purpose of the sealing layer is primarily to prevent leakage of fluid transported through the tubular body. For this reason, a sealing layer shall have a required flexibility (degree of flexibility) and can exhibit a required sealing function. Also, if the hose is intended to transport a cold storage fluid, the sealing layer should be able to withstand the cold storage temperature.
[0047]
The sealing layer may be made from the same basic material as the reinforcing layer or each reinforcing layer. As an option, the sealing layer may be a co-polymer of hexafluoropropylene and tetrafluoroethylene, available from DuPont Fluoroproducts using the trade name of fluoropolymers such as polytetrafluoroethylene (PFTE), Teflon FEP. It may be a fluorinated ethylene propylene copolymer such as a coalescence or a fluorinated hydrocarbon-perfluoroalkoxy available from DuPont Fluoro products using the trade name Teflon PFA. These films may be made using either extrusion or blowing.
[0048]
The sealing layer is preferably formed from a sheet of material that is bent into a tubular form by winding the sheet material in a helical manner. Like the reinforcement layer, this does not retain any resistance to the axial tension when the sealing layer or each sealing layer tends to pull apart the windings to disengage the windings. Means that. The sealing layer may include one single continuous layer of sheet material, or may include two or more single continuous layers of sheet material. More usually, however (and also according to the length of the hose), the layer or each layer of sheet material is formed of a plurality of divided lengths of sheet material aligned along the length of the hose. If desired, the sealing layer may include one or more heat-shrinkable sealing sleeves (ie, in tubular form) disposed over the inner reinforcement layer.
[0049]
The sealing layer preferably includes an overlapping layer of a plurality of films. Preferably, there are at least 2 layers, more preferably at least 5 layers, and even more preferably at least 10 layers. In practice, the sealing layer may comprise 20 layers, 30 layers, 40 layers, 50 layers or more layers of film. The upper limit of the number of layers depends on the overall size of the hose but cannot be required beyond 100 layers. Usually, a maximum of 50 layers is sufficient. The thickness of each layer of film typically may be in the range of 50 micrometers to 100 micrometers.
[0050]
Of course, more sealing layers than one layer may be provided.
[0051]
Particularly preferred embodiments of the sealing layer will be described later.
[0052]
The shaft reinforcing means may also be formed of the same material as the reinforcing layer or each reinforcing layer. Therefore, it is obvious that the shaft reinforcing means, the reinforcing layer or each reinforcing layer, and the sealing layer may all be formed of the same basic compound. However, the form of the compound should be different to provide the required function. For example, the axial reinforcing means provides a function of reinforcing in the axial direction, the reinforcing layer or each reinforcing layer provides reinforcement against circumferential stress, and the sealing layer provides a sealing function. We have found that UHMWPE materials, especially DYNEEMA and SPECTRA products, are optimal. These materials have also been found to work well in cold storage conditions. The preferred parameters (such as molecular weight range) of UHMWPE described above for the reinforcing layer are also appropriate for the shaft strengthening means. However, it should be noted in this respect that the parameters of UHMWPE used for the shaft strengthening means need not be the same as those of UHMWPE used for the reinforcing layer.
[0053]
It is also possible to provide axial strengthening means in the layer of the tubular body. However, the shaft strengthening means is preferably arranged between the tubular body and the outer grip member. As yet another preferred embodiment, the shaft reinforcing means may be provided in the layer of the tubular body, and the shaft reinforcing means may be provided between the tubular body and the outer grip member.
[0054]
When the hose is intended for cold storage applications, it is desirable to provide insulation on the tubular body. The insulating material can be provided between the outer wire and the tubular outer cylinder and / or outside the outer wire. The insulating material may include a material conventionally used as an insulating material in a low-temperature storage facility such as a synthetic foam material. Axial strengthening means are also preferably provided around the insulating layer to pressurize the insulating layer and maintain their structural integrity. The shaft reinforcing means around the insulating layer is preferably provided in addition to the shaft reinforcing means between the outer grip member and the tubular body. Particularly preferred forms of insulation are provided in further detail below.
[0055]
In another aspect of the invention, a hose is provided that includes a tubular body of soft material disposed between an inner and outer gripping member, wherein the tubular body is in the direction of at least one layer of weft and warp. A reinforcing layer of woven fabric formed from arranged fibers, wherein the reinforcing layer or each reinforcing layer has a warp of the fabric of less than 20 °, more preferably less than 15 °, most preferably relative to the axial direction of the hose. It arrange | positions so that it may become an angle of less than 10 degrees, It is characterized by the above-mentioned. The hose according to this aspect of the invention may be provided with any desired combination of the additional features described with respect to the hose according to the first aspect of the invention.
[0056]
In another aspect of the invention, a method of manufacturing a hose is provided that includes: That is,
(A) winding a wire around a tubular mandrel to form an inner coil;
(B) winding a sheet material around a tubular mandrel and an inner coil to provide a tubular body formed of the sheet material;
(C) covering the free end of the mandrel with a tubular shaft reinforcing outer cylinder so that the mandrel extends into the shaft reinforcing outer cylinder, and pulling the shaft reinforcing outer cylinder along the mandrel to at least the tubular body; Covering a part of
(D) winding a wire around the shaft-reinforced outer cylinder to form an outer coil;
(E) fixing the hose end produced in step (d), and
(F) Remove the hose from the mandrel.
[0057]
Preferably, the coil and sheet material is applied under tension to give the hose excellent structural integrity.
[0058]
Preferably, the sheet material in step (b) includes two reinforcing layers sandwiching the sealing layer as described above. In a preferred embodiment, an inner reinforcing layer in the form of a sheet is spirally wrapped around the inner coil and mandrel, after which a sealing layer in the form of a sheet is wrapped around the inner reinforcing layer. And then an outer reinforcing layer in the form of a sheet is wrapped around the sealing layer. Usually, a plurality of sealing layers are used.
[0059]
The tubular shaft-reinforced outer cylinder may be the same as the above-described shaft-reinforced outer cylinder, and is preferably a braid.
[0060]
Preferably, the inner and outer coils are applied in a helical arrangement with the same pitch, and the coil position of the outer coil is offset from the coil position of the inner coil to half the pitch length.
[0061]
In another aspect of the invention, a hose is provided that includes a tubular body of soft material disposed between an inner and an outer grip member, the tubular body for transporting fluid through the hose, and The hose serves to prevent leakage of fluid through the body, and the hose further includes a generally tubular braid disposed around the tubular body.
[0062]
In another aspect of the invention, a hose is provided that includes a tubular body of soft material disposed between an inner and outer gripping member, the tubular body sandwiched between inner and outer reinforcement layers. The sealing layer includes at least two polymer films, one of which is made of a first polymer and the other film is a first polymer. It is made of a different second polymer.
[0063]
In a particularly advantageous embodiment, one of the polymer films is harder than the other film, which causes different yield strains in the material properties at the use (operating) temperature and pressure. Preferably, the outer film is harder than the inner film. This effect is controlled in the sealing layer so that in the event of an undesired hose rupture, the more ductile polymer breaks the harder outer polymer while holding the internal pressure for a limited time. It is destruction, and it is to release pressure gradually.
[0064]
In a preferred embodiment, the maximum strain at break is greater than 100% at ambient temperature in the more ductile layer and at least less than 20% in the other layers.
[0065]
Each polymer film of the sealing layer is preferably polyamide, polyolefin or fluoropolymer.
[0066]
When the polymer film of the sealing layer contains polyamide, it may be an aliphatic polyamide such as nylon or an aromatic polyamide such as an aramid compound.
[0067]
One of the polymer films of the sealing layer is preferably polyolefin, and the other of the polymer films of the sealing layer is preferably a fluoropolymer.
[0068]
Suitable polyolefins include polyethylene, polypropylene or polybutylene homopolymers, or copolymers or terpolymers thereof. Preferably, the polyolefin film is uniaxially or biaxially oriented. More preferably, the polyolefin is polyethylene and most preferably the polyethylene is high molecular weight polyethylene, in particular UHMWPE as described in more detail above. The preferred parameters (such as molecular weight range) of UHMWPE described above for the reinforcing layer are also suitable for the sealing layer. However, it should be noted in this regard that the UHMWPE parameters used for the sealing layer need not be the same as the UHMWPE parameters used for the reinforcing layer.
[0069]
Since the sealing layer is intended to provide a sealing function, the sealing layer should be provided in the form of a film that is substantially impermeable to the fluid being transported. Thus, highly oriented UHMWPE needs to be provided in a form with a sufficient sealing function. These products are usually provided in the form of solid blocks that can be further processed to obtain the material in the desired form. The film may be produced by scraping a thin film from the surface of a solid block. Alternatively, the film may be UHMWPE blown films.
[0070]
Suitable fluoropolymers include polytetrafluoroethylene (PFTE), a copolymer of hexafluoropropylene and tetrafluoroethylene (tetrafluoroethylene-perfluoropropylene) available from DuPont fluoro products using the trade name Teflon FEP. Fluorinated ethylene-propylene copolymer, or fluorinated hydrocarbon-perfluoroalkoxy available from DuPont Fluoro products using the trade name Teflon PFA. These films may be made by either extrusion or blowing.
[0071]
Preferably, the sealing layer includes a plurality of layers of each polymer film. In embodiments, this layer may arrange the first and second polymers to stagger down to the thickness of the sealing layer. However, this is not the only possible arrangement. In another arrangement, all layers of the first polymer may be surrounded by all layers of the second polymer, or vice versa.
[0072]
The polymer film of the sealing layer is preferably formed from a sheet of material bent into a tubular form by winding the sheet material in a spiral. Each polymeric film may include a single continuous sheet that is wrapped around the inner reinforcing layer from one end of the hose to the other. More usually, however (according to the length of the hose), multiple divided length polymer films may be wrapped around the inner reinforcement layer, each film length being the length of the hose. Cover a part of. If desired, the sealing layer may include at least two heat shrinkable sealing sleeves (ie, tubular forms) disposed over the inner reinforcement layer. The at least two sleeves are made of different materials.
[0073]
The sealing layer comprises at least two different films, which are preferably arranged in an overlapping relationship. The sealing layer preferably includes at least five layers, more preferably at least 10 layers. In practice, the sealing layer may comprise a layer of film that overlaps 20, 30, 40, 50, or more layers. The upper limit on the number of layers depends on the overall size of the hose, but cannot be required beyond 100 layers. Usually, a maximum of 50 layers will be sufficient. The thickness of each film layer may typically be in the range of 50 micrometers to 100 micrometers. This layer can be made of at least two different types of polymeric films.
[0074]
Of course, it will be appreciated that more than one sealing layer may be provided.
[0075]
Preferably, the sealing layer further includes at least one layer partially or wholly containing a metal, a metal oxide or a mixture thereof. In the present specification, the indication of a metal-containing film includes a metal oxide-containing film even if not specifically mentioned. Thus, a metal layer can be a layer of metal film (ie, a separate layer consisting essentially of a metal, a metal oxide or a mixture thereof), or a layer of metal film or metal coating coated with a polymer. It may be a layer of a polymer film made. The metal layer is preferably a metal film coated with a polymer. The metal may be aluminum oxide, for example. The polymer may be, for example, polyester.
[0076]
Suitable polymer coated metal films include those available from HiFi Industrial Film of Stevenage, England using the trade names MEX505, MET800, MET800B, MET852, MET800B is preferred.
[0077]
An additional metal layer may be disposed on the surface of the sealing layer. Preferably, the further metal layer is arranged between the tubular body and the outer gripping member. A rock wool layer may also be provided here to improve thermal insulation, preferably between the sealing layer and the outer metal layer. The purpose is to create a thermal annulus between the two metal layers.
[0078]
In another aspect of the invention, a hose is provided that includes a tubular body of soft material disposed between an inner and outer gripping member, the tubular body sandwiched between inner and outer reinforcement layers. Including a sealing layer, the sealing layer being characterized as including UHMWPE. The preferred parameters (such as molecular weight range) of UHMWPE described above for the reinforcing layer are also suitable for the sealing layer. However, it should be noted in this regard that the UHMWPE parameters used for the sealing layer need not be the same as the UHMWPE parameters used for the reinforcing layer.
[0079]
In this aspect of the invention, if the sealing layer is formed of a heat-shrinkable sleeve, it is not important that the sleeve be made of a different material; they will be made of UHMWPE.
[0080]
In the most advantageous embodiment of the invention, the sealing layer comprises at least two polymer films of different materials and at least one layer of the film comprises ultra high molecular weight polyethylene.
[0081]
Preferably, the sealing layer further comprises a metal film or a metal-coated polymer film coated with at least one layer of polymer.
[0082]
In another aspect of the invention, a hose is provided that includes a tubular body of soft material disposed between an inner and outer gripping member, the tubular body sandwiched between inner and outer reinforcement layers. A sealing layer comprising at least one metal film (ie a separate layer consisting essentially of a metal, a metal oxide or a mixture thereof) or a metal coated with a polymer It is characterized by including a layer of film or a layer of metallized polymer film.
[0083]
Metal-containing films are reflective and thus reduce heat loss or heat gain, which is particularly useful for cold storage applications. In addition, the metal-containing film provides excellent barrier properties, thus reducing vapor transmission, which is useful for preventing the material from losing the gas it transports.
[0084]
When the hose is intended for low temperature applications, it is desirable to provide a thermal insulation on the tubular body. The insulating material may be provided between the outer wire and the tubular member and / or outside the outer wire. The insulating material may include materials that have been traditionally used for low temperature storage facilities, such as synthetic foam. One particularly preferred form of insulation is described below.
[0085]
One aspect of the invention relates to improving the flexibility performance of the hose. The present invention broadly includes providing means for holding the outer wire in place without compromising the flexibility performance of the hose.
[0086]
In another aspect of the present invention, a tubular body of soft material disposed between an inner and outer grip member, characterized by a cured resin matrix provided around the tubular body. A hose comprising an outer grip member, wherein the outer grip member is at least partially embedded in the resin substrate to limit relative movement between the outer grip member and the rest of the hose. Has been.
[0087]
The cured resin substrate should have sufficient flexibility to allow the hose to bend to the extent required for the specific application of the hose. Obviously, some applications may require more flexibility than others.
[0088]
The resin substrate preferably comprises a synthetic polymer such as polyurethane. In particular, the resin substrate is preferably made from a material that can be applied to the hose in liquid form before curing. In general, the uncured resin can be applied to the hose by spraying, pouring, or painting. This is where the uncured resin is applied over the outer surface of the tubular body and outer gripping member, where it remains solid and cures to form a flexible coating. The curing mechanism may be either light or moisture.
[0089]
The resin substrate may adhere to the layer below the outer grip member and also any layer provided on the outer surface of the resin substrate. At least one of the layers adjacent to the cured resin substrate can withstand the low temperature storage temperature, so if the resin substrate cracks due to the low temperature storage temperature, the adjacent layer is The resin base material is held together by adhesion between the base material and the adjacent layer. The most stable structure is achieved when adjacent layers on both sides of the resin substrate are bonded.
[0090]
We have also found that certain materials can provide the hose with exceptional thermal insulation, especially at low storage temperatures, and in particular, we have fabrics formed from basaltic fibers that have particularly good thermal insulation. Found to provide sex.
[0091]
Thus, in another aspect of the present invention, there is provided a hose including a tubular body of soft material disposed between an inner and an inner grip member and a heat insulating layer provided around the tubular body, and the heat insulating layer Is characterized by including a fabric formed from basaltic fibers.
[0092]
Suitable basaltic fiber fabrics are available from Sudaglass Fiber Company using the trade names BT-5, BT-8, BT-10, BT-11, and BT-13. The preferred thickness of the fabric is from about 0.1 mm to about 0.3 mm. Multiple layers of basaltic fabric may be used if desired.
[0093]
We have also found that the thermal insulation performance of the basaltic fabric is improved under pressure, and therefore it is preferred to provide a pressurized layer around the basaltic fabric which serves to pressurize the basaltic layer.
[0094]
In addition to the basaltic fabric layer (s), the insulating layer may further include layers made of other insulating materials such as polymer foam.
[0095]
It is preferable that the insulating layer further includes at least one reinforcement layer. The reinforcing layer may comprise a synthetic polymer such as polyester, polyamide or polyolefin. The reinforcing layer may be made of the same material as the inner and outer reinforcing layers of the tubular body described above. In particular, the reinforcing layer of the heat insulating layer is preferably ultra high molecular weight polyethylene (UHMWPE) such as DYNEEMA or SPCTRA described above.
[0096]
The tubular body preferably includes at least one reinforcing layer and at least one sealing layer. More preferably, there are at least two reinforcing layers having a sealing layer sandwiched therebetween. The tubular body preferably has the same characteristics as the tubular body described above.
[0097]
The tubular body may further comprise one or more thermal insulation layers made of conventional insulating materials and / or made of the basaltic fiber fabric described above.
[0098]
The hose is also preferably provided with the above-described shaft strengthening means.
[0099]
In another aspect of the invention, a method of manufacturing a hose is provided that includes: That is,
(A) winding a wire around a tubular mandrel to form an inner coil;
(B) winding a sheet material around a tubular mandrel and an inner coil to provide a tubular body formed of the sheet material;
(C) winding a wire around the tubular body to form an outer coil;
(D) applying a curable liquid resin on the outer surface of the tubular body and the outer wire;
(E) curing the resin;
(F) fixing the hose end produced in step (e), and
(G) Remove the hose from the mandrel.
[0100]
Preferably, the method further includes applying a thermal insulation layer over the cured resin. The insulating layer preferably comprises a fabric formed from basaltic fibers as described above.
[0101]
In step (c), the tubular body may include a tubular body as described above. In particular, the tubular body may include one or more thermal insulation layers made of conventional insulating materials and / or made of the basaltic fiber fabric described above.
[0102]
Curing can also occur by simply leaving the coated hose in the air, or can be effected or accelerated by aggressive means such as heating.
[0103]
The cured resin base material may contain gas bubbles as described later.
[0104]
Another aspect of the invention relates to improving the heat resistance and / or buoyancy of the hose. This broadly involves the use of a layer comprising a plastic material having gas bubbles injected therein.
[0105]
In another aspect of the invention, a hose is provided that includes a tubular body of soft material disposed between an inner and outer gripping member, characterized by a layer of plastic material surrounding the tubular member, The plastic material contains gas bubbles therein.
[0106]
The plastic material is preferably polyurethane. The plastic material is preferably applied to the tubular body by spraying the plastic material in liquid form on the surface of the tubular body and then allowing it to cure. Curing can also occur by simply leaving the coated hose in the air, or can be effected or accelerated by positive means such as heating.
[0107]
The gas bubble may be entrained by injecting gas into the plastic material before spraying while it is in liquid form.
[0108]
The resulting layer of the gas-containing plastic material not only has some of the beneficial structural properties of the plastic material itself, such as excellent wear resistance and compression resistance, but also has substantially improved thermal insulation. It also has improved buoyancy due to the presence of gas and can be used to produce hoses that can float in water and have buoyancy distributed uniformly along its length.
[0109]
Preferably, the gas-containing plastic material is coated with an additional layer of plastic material, which plastic material does not contain any gas bubbles. Preferably, this further layer of plastic material is firmly bonded to the gas-containing layer. The further layer of plastic material may be the same plastic material as the gas-containing layer. Preferably, the further layer of plastic material comprises polyurethane.
[0110]
Both layers of plastic material can be applied by different techniques than spraying, such as pouring, coating, or extrusion.
[0111]
Any suitable gas, including air, nitrogen or inert gas, may be used to form the bubbles.
[0112]
The specific gravity of the polyurethane is preferably about 1.2 before aeration.
[0113]
The hose typically has a specific gravity of about 1.8 without a gas containing layer. Preferably, the hose has an overall specific gravity of less than 1, preferably less than 0.8 after application of the gas-containing layer. The thickness of the PU coating can be, for example, about 4-8 mm, preferably about 6 mm. The gas bubbles are preferably less than about 2 mm in diameter.
[0114]
The gas bubble-containing layer may also be used in the above-described hose embodiment. In particular, the present invention can include a layer including a cured resin substrate, as described above, in addition to the gas-containing layer. In this configuration, the gas-containing layer can typically be disposed on the surface of the cured resin substrate. The gas-containing layer can also be replaced by a cured resin substrate, whereby the gas-containing layer holds the grip member embedded therein and limits the relative movement of the outer grip member.
[0115]
In another aspect of the invention, a method of manufacturing a hose is provided that includes: That is,
(A) winding a wire around a tubular mandrel to form an inner coil;
(B) winding a sheet material around a tubular mandrel and an inner coil to provide a tubular body formed of the sheet material;
(C) winding a wire around the tubular body to form an outer coil;
(D) applying a curable aerated liquid resin on the outer surface of the tubular body and outer wire;
(E) curing the resin to form a solid plastic coating containing gas bubbles therein;
(F) fixing the hose end produced in step (e), and
(G) Remove the hose from the mandrel.
[0116]
The term breathable is used to mean that the resin is filled with a gas, thereby, with curing, the resin forms a solid material containing gas bubbles therein. As described above, the gas may be air, but is not necessarily air.
[0117]
In another aspect of the invention, an end fitting is provided for terminating a hose terminal including a tubular body of soft material disposed between a spiral inner wire and an outer wire, the terminal The component is a seal adapted to seal at least a portion of the tubular body between the sealing member and the inner member, i.e., the inner member adapted to be at least partially disposed in the hose. To reduce the axial load on the hose between the stop member and the sealing member and the inner member, or to transfer the axial load applied to the hose around the sealing member for removal It is characterized by including separate load transferring means adapted to.
[0118]
Preferably, the sealing member is adapted to seal at least a portion of the tubular body that surrounds the entire circumference between the sealing member and the inner member.
[0119]
The inner member is preferably substantially cylindrical and the sealing member is preferably in a ring shape adapted to receive the inner member therein, whereby the tubular body is Between the outer surface of the ring and the inner surface of the ring.
[0120]
Sealing between the sealing member and the inner member can be accomplished in a number of ways. For example, in one embodiment, the sealing member may be provided in the form of a split ring that can be tightened to provide a suitable seal. In another embodiment, the sealing member may include only a sealing ring that is an interference fit with an inner member.
[0121]
However, in a preferred embodiment, the sealing member includes an inner sealing ring and an outer split ring that can be clamped to mate the sealing ring with the tubular body and the inner member. In this embodiment, the sealing ring is preferably an interference fit with an inner member to further improve sealing.
[0122]
The inner member, sealing ring and split ring may be any suitable material. Typically, the inner member and the split ring can be made of stainless steel. The sealing ring may be made of stainless steel but is preferably made of polytetrafluoroethylene (PTFE).
[0123]
The sealing member preferably has the characteristics of the sealing member described later.
[0124]
The load transfer means preferably includes a hose engaging member, a load transmitting member, and an end member fixed to the inner member. As for arrangement | positioning, a sealing member is arrange | positioned between a load transmission member and a terminal member, and a hose engagement member and a terminal member are connected through a load transmission member.
[0125]
The hose engaging member is adapted to engage the hose in such a way that at least a portion of the axial force in the hose is transmitted from the hose to the hose coupling member. The hose engaging member transmits these forces to the load transfer member, and the load transfer member transmits these forces to the terminal member. In this way, at least a portion of the axial force in the hose diverts to the sealing member, thereby improving the reliability of the sealing provided by the sealing member.
[0126]
The inner member and load transfer means preferably include a portion configured to receive the wire of the hose. The inner member can have a helical recess in it to accept the inner wire, and the load transfer means can have a helical recess in it to accept the outer wire. Preferably, it is a hose engaging member of a load transfer means with a helical recess.
[0127]
The load transfer member preferably includes a load transfer plate, which is typically disk-shaped and has an opening adapted to receive a hose therethrough, the plate being a hose. It has a surface that can engage the engaging member, so that a load can be transferred from the hose engaging member to the plate. The load transfer member preferably further includes a load transfer rod secured between the plate and the terminal member to transfer the load from the plate to the terminal member. A fastening member such as a nut can be provided on the rod.
[0128]
The inner member preferably has a hose end adapted to extend to the end of the hose and a tail end remote from the hose end. The terminal member is disposed on one side of the sealing member adjacent to the tail portion, and the hose engagement member is disposed on the other side of the sealing member adjacent to the hose terminal.
[0129]
Preferably, the outer surface of the inner member is provided thereon with at least one formation suitable for engagement of the part of the tubular member under the sealing ring. This or each component serves to improve the sealing of the tubular member and to make it more difficult for the tubular member to be pulled from between the inner member and the sealing ring. The component or each component preferably includes a protrusion extending around the outer surface around the outer surface of the inner member. Desirably, there are two or three such components.
[0130]
In another aspect of the invention, a method is provided for manufacturing a hose comprising: That is,
(A) winding a wire around a tubular mandrel to form an inner coil;
(B) wrapping the sheet material around a tubular mandrel and an inner coil to provide a tubular body formed of the sheet material;
(C) winding a wire around the tubular body to form an outer coil; and
(D) Remove the hose from the mandrel. And it is characterized by the following processes. That is,
(E) placing the inner member at the open end of the hose;
(F) securing the load transfer means to the outer surface of the hose; and
(G) A sealing member is fixed to the outer surface of the tubular body.
[0131]
Preferably, this method further includes the following steps between step (b) and step (c). That is,
(H) covering the tubular shaft reinforcing member from the free end of the mandrel so that the mandrel extends into the shaft reinforcing member, and pulling the shaft reinforcing member along the mandrel so that it is at least part of the tubular body; Coating.
[0132]
Preferably, the shaft reinforcing member is fixed by load transfer means, and the method further includes the following steps after step (f). That is,
(I) The tubular shaft reinforcing member is folded back to a part of the load transfer means.
[0133]
Preferably, the coil and sheet material is applied under tension to provide excellent structural integrity to the hose.
[0134]
Preferably, the sheet material in the step (b) includes two reinforcing layers sandwiching the sealing layer as described above. In a preferred embodiment, the inner reinforcing layer in the form of a sheet is spirally wrapped around the inner coil and mandrel, after which a sealing layer in the form of a sheet is wrapped around the inner reinforcing layer. After being wound in a spiral, an outer reinforcing layer in the form of a sheet is wound around the sealing layer. Usually, a plurality of sealing layers are used.
[0135]
Preferably, the inner and outer coils are applied to a helical structure having the same pitch, and the coil position of the outer coil is offset from the coil position of the inner coil to half the pitch length.
[0136]
The hose can also be removed from the mandrel before the end piece is placed therein. Instead, the end piece slides the inner mandrel along to the hose end, and then secures the remainder of the hose to the end piece while the end piece and the rest of the hose remain on the mandrel. By doing so, it can be installed in the remainder of the hose.
[0137]
A separate end piece may of course be applied to each end of the hose.
[0138]
The present invention relates to an improvement in sealing a hose terminal.
[0139]
In another aspect of the invention, there is provided a terminal component for sealing a hose terminal that includes a tubular body of soft material disposed between a spiral inner wire and an outer wire, the terminal component comprising: An inner member adapted to be at least partially disposed within the hose, and a sealing ring adapted to seal at least a portion of the tubular body between the sealing ring and the inner member Wherein the sealing member includes a sealing ring and a pressure member for pressing the sealing ring into a sealing engagement with the component of the tubular body ( compression member), and the pressure member may be clamped against the sealing member to selectively increase or decrease the compression force of the pressure member against the sealing member. It is possible.
[0140]
In one particularly useful embodiment, the pressure member can be clamped against the sealing member to selectively increase or decrease the compression force of the pressure member against the sealing member.
[0141]
In another particularly useful embodiment, the pressure member and the sealing ring are movably secured to the hose.
[0142]
Thus, according to the present invention, there is no unrecoverable plastic deformation in the constituent parts of the terminal parts.
[0143]
Preferably, the pressure member is responsive to compress the sealing ring equally in all directions.
[0144]
Preferably, the pressure member has an adjustable diameter and further includes a fastening member that can apply force to reduce the diameter of the pressure member, thereby providing a pressure member. Pressurize the sealing ring inside. The pressure member preferably includes a split ring or a jubilee clip.
[0145]
In a particularly preferred embodiment, the pressure member is made of a material that does not shrink more than the sealing ring when cooled. This provides an advantageous method of manufacturing the hose, as described below. The sealing ring and pressure member may be any suitable material. There are many materials that have the desired difference in shrinkage under cooling. The pressure member is preferably stainless steel, and the sealing ring is preferably polytetrafluoroethylene (PTFE). More preferably, the sealing ring includes reinforced PTFE, such as glass filled PTFE, to help prevent creep. The sealing ring preferably comprises 10% to 20% by weight glass filling.
[0146]
The inner member is preferably made from a material that does not shrink more than the sealing ring when cooled. This feature has the effect that when the terminal part is cooled, the sealing ring contracts more than the inner member, thereby tightening the grip of the sealing ring to the inner member and improving the sealing. . The inner member may be made of any suitable material. Stainless steel has been found to be particularly suitable.
[0147]
Preferably, the outer surface of the inner member is provided under the sealing ring with at least one structure adapted thereon for engaging the components of the tubular member. The component or each component stretches the film, which improves the sealing of the tubular member and serves to make it more difficult for the tubular member to be pulled from between the inner member and the sealing ring. This stretching makes the surface of the film flatter and smoother under sealing. The component or each component preferably includes a protrusion extending around the outer surface around the outer surface of the inner member. Desirably, there are two or three such components.
[0148]
The sealing ring is preferably an interference fit with an inner member.
[0149]
In a preferred embodiment, the terminal component further includes the load transfer means described above.
[0150]
In another aspect of the invention, a hose is provided that includes a tubular body of soft material disposed between a spirally wound inner and outer wire, the tubular body serving to move fluid through the hose. And has a role of preventing leakage of fluid through the main body, and the hose further includes a terminal part as described above.
[0151]
The hose engaging member can transfer the load from the hose with only a frictional force between the hose and the hose engaging member. However, the hose engaging member is preferably adapted to secure the hose portion that is folded back to the outer portion of the hose engaging member. This arrangement allows the folded portion of the hose to transmit the load to the hose engagement member. The folded portion of the hose may be a portion of the tubular body, but is preferably a shaft reinforcing means in the form of a braid as will be described later.
[0152]
The tubular body preferably includes at least one reinforcing layer and at least one sealing layer. More preferably, there are at least two reinforcing layers having a sealing layer sandwiched between them. The tubular body preferably has the same characteristics as the tubular body described above.
[0153]
The tubular body may further comprise one or more insulating layers made of a conventional insulating material and / or made of a basaltic fiber fabric as described above.
[0154]
The hose is also preferably provided with the above-described shaft strengthening means.
[0155]
In another aspect of the invention, a method of manufacturing a hose is provided that includes: That is,
(A) winding a wire around a tubular mandrel to form an inner coil;
(B) wrapping the sheet material around a tubular mandrel and an inner coil to provide a tubular body formed of the sheet material;
(C) Wrap a wire around the tubular body to form an outer coil, and (d) Remove the hose from the mandrel. This is characterized by the following steps. That is,
(E) Attach an inner member to the open end of the hose,
(F) putting a sealing ring over the outer surface of the tubular body; and
(G) A pressure member is placed on the sealing ring, and the sealing member is pressed against the sealing engagement portion between the tubular member and the inner member using the pressure member.
[0156]
Preferably, the pressure member is made of a material that does not shrink more than the sealing ring when cooled. Preferably, the pressure member also includes means for adjusting the compressive force applied to the sealing ring, the split ring being particularly suitable for use as a pressure member. This arrangement allows a particularly preferred manufacturing process.
[0157]
In this process, the pressure member is applied to the sealing ring and tightened, after which the pressure member and the sealing ring are subjected to at least one cooling cycle. This causes the sealing member to contract in relation to the pressure member, thereby reducing the compressive force applied by the pressure member. While cooling is maintained, the compressive force applied by the pressure member is readjusted to return it to approximately the same level as before cooling, after which the temperature increases. This cycle is applied as many times as desired. The cooling cycle is applied at least two or three times, and at each time the end piece is preferably cooled to a temperature at least 5 ° C. below the intended hose operating temperature. This technique has three important advantages.
[0158]
First, if the hose is operated at a temperature above the cooling temperature, the sealing ring will receive additional compression from the pressure member due to possible thermal expansion of the sealing member after cooling is stopped. obtain.
[0159]
Second, the hose can have substantial seal energization at least as low as the cooling temperature. This is particularly useful when the hose is used in cold storage applications. Thus, it is preferred that the temperature at which the hose is cooled is preferably as low as the temperature that the hose can undergo during its intended use. In general, the cooling temperature is preferably −50 ° C. or lower, more preferably −100 ° C. or lower, and further preferably −150 ° C. or lower. Preferably, the cooling is performed with liquid nitrogen so that the cooling temperature can be as low as about -196 ° C.
[0160]
Third, the possibility of creep damage is greatly reduced or even eliminated by utilizing the hydrostatic stress provided by the pressure member.
[0161]
The inner member is preferably made of a material that does not shrink more than the sealing ring when cooled. This has the effect that by cooling the terminal part, the sealing ring grips the tighter inner member, thereby improving the sealing of the terminal part when the hose is operated at low temperatures.
[0162]
Preferably, the coil and sheet material is applied under tension to provide excellent structural integrity to the hose.
[0163]
Preferably, the sheet material in the step (b) includes two reinforcing layers sandwiching the sealing layer as described above. In a preferred embodiment, the inner reinforcing layer in the form of a sheet is spirally wrapped around the inner coil and mandrel, after which the sealing layer in the form of a sheet is wrapped around the inner reinforcing layer. The outer reinforcing layer in the form of a sheet is then wound around the sealing layer. Usually, a plurality of sealing layers are applied.
[0164]
Preferably, the inner and outer coils are applied to a helical structure having the same pitch, and the coil position of the outer coil is offset from the coil position of the inner coil to half the pitch length. .
[0165]
The hose can be removed from the mandrel before the end piece is placed therein. Instead, the end piece slides the inner mandrel along to the hose end and then secures the remainder of the hose to the end piece while the end piece and the rest of the hose remain on the mandrel. Thus, it can be installed in the remaining part of the hose.
[0166]
In the aspects of the invention described above, the gripping members typically each include a helically bent wire. The spirals of the wire are typically arranged so that they are offset from each other by a distance corresponding to half the helical pitch. The purpose of the wire is to hold the tubular body firmly between them, keeping the tubular body layer intact and providing structural integrity to the hose. The inner and outer wires can be, for example, mild steel, austenitic stainless steel or aluminum. If desired, the wire may be coated with galvanizing or polymer.
[0167]
Even though the wires that make up the grip member can have a high tensile strength, an array of coil-shaped wires can be seen that can deform when the grip member is subjected to relatively small axial tensions. . Any significant deformation of the coil will quickly destroy the structural integrity of the hose.
[0168]
The hose according to the present invention can be provided for use in a wide variety of conditions, such as temperatures above 100 ° C., temperatures from 0 ° C. to 100 ° C., and temperatures below 0 ° C. Depending on the preferred choice of material, the hose can be used at temperatures below -20 ° C, temperatures below -50 ° C, or even temperatures below -100 ° C. For example, for transportation of LNG, the hose may have to be used at temperatures of -170 ° C or lower. Furthermore, it is anticipated that the hose can be used to transport liquid oxygen (bp-183 ° C.) or liquid nitrogen (bp-196 ° C.), where the hose is at −200 ° C. or lower. You may have to use it.
[0169]
The hose according to the invention can also be provided for use in a variety of different roles. Typically, the internal diameter of the hose ranges from about 2 inches (51 mm) to about 24 inches (610 mm), more typically from about 8 inches (203 mm) to about 16 inches (406 mm). Can span a range. In general, the working (operating) pressure of the hose is in the range from about 500 kPa gauge pressure to about 2000 kPa gauge pressure, or can be up to about 2500 kPa gauge pressure. These pressures are related to the working pressure of the hose and not to the burst pressure (which must be greater than multiple times). The flow rate depends on the liquid medium, pressure and inner diameter. The flow rate is 1000m ^Three / H to 12000m ^Three Typically up to / h.
[0170]
The hose according to the invention can also be provided for use against corrosive substances such as strong acids.
[0171]
FIG. 1 shows the stress that hose H typically experiences during use. The circumferential stress is indicated by the arrow HS, which is the stress acting along the tangent around the hose H. The axial stress is indicated by the arrow AS, which is the stress acting in the axial direction along the length of the hose H. Flexing stress is denoted FS, which is the stress acting transversely to the longitudinal axis of the hose H when the hose H is bent. The torsional stress is denoted TS, which is the torsional stress that acts on the longitudinal axis of the hose. The compressive stress is designated CS, which results from a load applied radially on the outer surface of the hose H.
[0172]
The circumferential stress HS is generated by the pressure of the liquid in the hose H. The axial stress AS is generated by the pressure of the liquid in the hose, and also by a combination of the weight of the liquid in the hose H and by the weight of the hose H itself. The bending stress FS is caused by the need to bend the hose H in order to put the hose H in place and by the movement of the hose H during use. The torsional stress TS is generated by torsion of the hose. Prior art hoses can generally withstand circumferential stress HS, bending stress FS and torsional stress TS, but not so much axial stress AS. For this reason, when prior art hoses are subjected to large axial stress AS, they generally must be assisted to minimize the axial stress AS.
[0173]
The problem of withstanding axial stress AS is solved by the present invention. In FIG. 2, the hose according to the present invention is generally indicated by the reference numeral 10. For clarity, the various layers of winding are not shown in FIG. 2 and other figures.
[0174]
The hose 10 includes a tubular body 12 that includes an inner reinforcement layer 14, an outer reinforcement layer 16 and a sealing layer 18 sandwiched between layers 14 and 16. In general, the tubular outer cylinder 20 provides axial reinforcement and is disposed around the outer surface of the outer reinforcing layer 16.
[0175]
The tubular body 12 and the tubular outer tube 20 are disposed between the spirally wound inner wire 22 and the spirally wound outer wire 24. The inner wire 22 and the outer wire 24 are placed offset from each other by a distance that corresponds to half the pitch length of the coil helix.
[0176]
The insulating layer 26 is disposed around the outer wire 24. The insulating layer may be a conventional insulating material such as plastic foam, or may be a material described below with respect to FIG.
[0177]
The reinforcing layers 14, 16 include a woven fabric of synthetic material such as UHMWPE or aramid fibers. FIG. 3 illustrates the inner reinforcing layer 14 from which it is apparent that the inner reinforcing layer 14 includes fibers 14a disposed in the warp direction W and fibers 14b disposed in the weft direction F. Let's go. In FIG. 3, only layer 14 is shown for clarity. The axial strength of the hose 10 is such that the warp direction W is less than 20 ° with respect to the longitudinal axis of the hose 10, and the inner reinforcing layer 14 is typically as low as 15 °. It was unexpectedly discovered that it can be improved by placement. This angle is indicated by the symbol α in FIG. The structure and orientation of the outer reinforcing layer 16 are substantially the same as the inner reinforcing layer 14, and the angle α for the outer reinforcing layer 16 may be the same as the angle α for the inner reinforcing layer 14, Or it may be different.
[0178]
The sealing layer 18 is wrapped around the outer surface of the inner reinforcing layer 14 to provide a fluid tight seal between the inner reinforcing layer 14 and the outer reinforcing layer 16. Includes multiple layers of plastic film.
[0179]
The hose 10 further includes a reinforcing layer 21 disposed between the outer cylinder 20 and the outer wire 24. The reinforcing layer 21 may have the same characteristics as the outer cylinder 20 and the tubular body 12.
[0180]
The tubular outer cylinder 20 is formed from two sets of fibers 20a and 20b knitted to form a tubular braid. This is shown in FIGS. 4A and 4B, in which only the tubular outer cylinder 20 is shown for clarity. There is a space 28 between the pair of fibers 20a, 20b, so that the fibers 20a, 20b can contract toward the space 28 when the tubular outer cylinder 20 is pulled in the axial direction. This acts in a direction to reduce the diameter of the tubular outer cylinder 20 and tightens the periphery of the tubular body 12, thereby increasing the structural integrity and burst pressure resistance of the hose 10. FIG. 4B shows the tubular outer cylinder 20 in a clamped state.
[0181]
The sealing layer 18 is shown in more detail in FIG. Providing the sealing layer 18 improves the resistance of the hose to bending stress FS and circumferential stress HS.
[0182]
As shown in FIG. 6, the sealing layer 18 comprises a plurality of first polymers (highly oriented UHMWPE) interleaved with layers 18b of a film made of a plurality of second polymers (PFTE or FEP). ), And the two polymers have different stiffnesses. The layers 18a, 18b are wrapped around the outer surface of the inner reinforcement layer 14 and provide a fluid tight seal between the inner reinforcement layer 14 and the outer reinforcement layer 16. As mentioned above, the layers 18a, 18b do not necessarily have to be staggered. For example, all the layers 18a may be arranged by the same thing, or all the layers 18b may be arranged by the same thing.
[0183]
Insulating layer 26 is shown in more detail in FIG. 7, which shows further details of insulating layer 26. The insulating layer mainly relates to improving the resistance of the hose to bending stress FS and insulating the hose.
[0184]
Insulating layer 26 includes an inner layer 26a formed of polyurethane applied by spraying, pouring, or otherwise applied over tubular body 12 and outer wire 24. After curing, the polyurethane layer 26a forms a solid substrate in which the outer wire 24 is embedded. This helps to maintain the fixed outer wire 24 in place. In a preferred embodiment, the inner layer 26a is provided with bubbles therein.
[0185]
The insulating layer 26 includes a layer 26b on the layer 26a. Layer 26b includes a fabric formed from basaltic fibers. Layer 26b provides most of the insulation of hose 10.
[0186]
The insulating layer 26 further includes a layer 26c on the layer 26b. Layer 26c includes UHMWPE such as DYNEEMA or SPECTRA. The purpose of layer 26c is primarily to provide reinforcement against circumferential and bending stresses.
[0187]
The insulating layer 26 further includes a pressure layer 26d. The purpose of the pressure layer 26d is to pressurize the layer 26b, as we have found that the insulation of the basaltic fabric layer 26b is greatly improved under pressure. The pressure layer 26d may include, for example, a rope or cord that is tightly wrapped around the layer 26c. Preferably, the pressure layer 26d includes an axially reinforced outer cylinder like the outer cylinder 20 described above.
[0188]
An additional polyurethane layer (not shown) containing gas bubbles may be provided on layer 26d to further improve the insulation and buoyancy of hose 10. An additional polyurethane layer (not shown) that does not contain gas bubbles may be provided on the gas-containing polyurethane layer. Additional polyurethane layers may be provided in layer 26d in addition or alternatively. It is also possible for the layer 26a itself to contain gas bubbles.
[0189]
The hose 10 can be manufactured by the following construction method. As a first step, an inner wire 22 is wrapped around a support mandrel (not shown) to provide a helical arrangement with the desired pitch. The diameter of the support mandrel corresponds to the desired inner diameter of the hose 10. Thereafter, the inner reinforcing layer 14 is wound around the inner wire 22 and the support mandrel so that the warp direction W is set to a desired angle α.
[0190]
Thereafter, a plurality of layers of the plastic films 18 a and 18 b constituting the sealing layer 18 are wound around the outer surface of the inner reinforcing layer 14. Typically, the films 18a, 18b have a length that is substantially shorter than the length of the hose 10, so that a plurality of divided length films 18a, 18b are wrapped around the inner layer 14. Must be done. These films 18 a and 18 b are preferably arranged alternately up to the thickness of the sealing layer 18. The thickness of the sealing layer is generally a layer of films 18a and 18b divided into five layers.
[0191]
After that, the outer reinforcing layer 16 is set to the sealing layer so that the warp direction W is set to a desired angle (may be α or other angle close to α). 18 is wound around. The tubular shaft reinforcing outer cylinder 20 is pulled up on the outer surface of the outer reinforcing layer 16. Thereafter, a further reinforcing layer 21 is wound around the outer cylinder 20.
[0192]
Thereafter, the outer wire 24 is wound around a further reinforcing layer 21 to provide a helical arrangement with the desired pitch. The pitch of the outer wire 24 is typically the same as the pitch of the inner wire 22, and the position of the wire 24 is typically the distance that the coil of the wire 24 corresponds to half the pitch length of the wire 22. Offset from the coil. This is illustrated in FIG. 2, where the pitch length is indicated by the symbol p.
[0193]
Thereafter, polyurethane resin is sprayed onto the outer surface of the reinforcing layer 21 to form a resin coating on the reinforcing layer 21 and the outer wire 24. The resin is then left to cure to form layer 26a. This resin may be vented prior to curing (typically prior to spraying or application) to provide gas bubbles therein. A basaltic fabric layer 26b is then wrapped around the polyurethane layer 26a, and then the UHMWPE layer 26c is wrapped around the layer 26b. Finally, a pressure layer 26d is provided on the layer 26c.
[0194]
The end of the hose 10 can be sealed by folding the sleeve inside the insert inside of the hose 10. This termination is typically done after removing the hose 10 from the mandrel.
[0195]
You may seal the terminal of the hose 10 using the terminal component 200 shown in FIG. In FIG. 8, the hose 10 is not shown for clarity. The terminal component 200 includes a tubular inner member 202 having a hose terminal 202a and a tail portion 202b. The terminal component 200 further includes a sealing member having a PTFE sealing ring 204 and a stainless steel split ring 206 around the PTFE sealing ring 204.
[0196]
The terminal component 200 further includes a load transfer means having a hose coupling member 208, a load transfer member 210 and a terminal member 212 in the form of a disk-shaped plate. The load transfer member includes a disk-shaped plate 214 and at least one load transfer rod 216. In FIG. 2, there are two rods 216, but three or more rods 216 can be provided. A fastening nut 218 is attached to each rod 216. Plates 212 and 214 have holes 212a and 214a, respectively, for receiving rods 216.
[0197]
Each of the plates 212 and 214 may be a Simon plate, the hose engagement member 202 may be a Gedring, and the split ring 206 may be an Ericring.
[0198]
The plate 212 is further provided with a hole 212b, and the tail 202b of the inner member 202 is provided with a hole 202c. The fixing bolt 220 extends through the holes 202b and 212b, and fixes the plate 212 to the tail portion 202a of the inner member 202. In FIG. 2, there are two fixing bolts 220 and holes associated therewith, however, fewer or more fixing bolts 220 and holes associated therewith may be provided.
[0199]
The hose engagement member 208 includes an inner helical recess in the form of a groove 208a adapted to receive the outer wire 24 of the hose 10 therein. Inner member 202 includes an outer helical recess in the form of a groove 202d adapted to receive inner wire 22 therein. As can be seen from FIG. 2, like the inner wire 22 and the outer wire 24, the grooves 208 a and 202 d are arranged at intervals of half the pitch length p.
[0200]
The inner member 202 includes two outer peripheral projections 202e disposed below the sealing ring 204. These protrusions 202e help to improve the sealing of the tubular member 20 between the inner member 202 and the sealing ring 204, and help prevent the tubular member from being inadvertently pulled out of position.
[0201]
The hose 10 is fixed to the terminal component 200 as follows. Inner member 202 is threaded to the end of hose 10 so that hose 10 is positioned proximate to plate 212. The inner wire 22 is received in the groove 202d, and the outer wire 24 is received in the groove 208a. The inner wire 22 and the outer wire 24 are cut short so that they do not extend along the inner member 202 beyond the grooves 202d, 208a. The insulation 26 is also cut short at this point. The inner reinforcement layer 14 may also be cut short at this point, or it may be cut short at some point before the inner reinforcement layer 14 reaches the sealing ring 204. This means that the sealing layer 18 directly engages the outer surface of the inner member 202. However, the remainder of the tubular body 12 is adapted to extend along the inner member 202 between the inner member 202 and the sealing ring 204.
[0202]
Thereafter, the hose engagement member 208 is tightened, which tightens the hose 10 and makes it a hard engagement with the hose 10. The nut 218 is then tightened, which causes some axial tension on the hose 10 and thereby has some effect on the system. These forces are sequentially transmitted from the hose engagement member 208 to the plate 214, rod 216, plate 212 and inner member tail 202b. Tubular member 20 is pulled over the upper surface of hose engagement member 208 and secured to protrusion 208b extending from the upper surface of hose engagement member 208.
[0203]
The tubular body 12 extends below the sealing ring 204. After the hose engagement member 208 and nut 218 are tightened, the split ring 206 is tightened to increase the force applied on the tubular body 12 by the sealing ring 204.
[0204]
Thereafter, the terminal component 200 is cooled to a low temperature with liquid nitrogen. As a result, the sealing ring 204 contracts compared to the split ring 206, thereby reducing the compressive force applied to the sealing ring 204 by the split ring 206. While the split ring 206 and the sealing ring 204 are at a relatively low temperature, the split ring 206 is retightened. Thereafter, the temperature is raised to ambient temperature, whereby the compressive force on the sealing ring is increased by greater expansion of the sealing ring 204 compared to the split ring 206.
[0205]
This completes the terminal part of the hose 10. The hose engagement member 208 provides some sealing at the end of the hose 208 and serves to transmit the axial force in the hose 10 around the sealing ring 204. The sealing ring 204 provides the remainder of the hose 10 seal.
[0206]
5A to 5D show three applications of the hose 10. 5A-5C, a floating manufacturing, storage and unloading ship (FPSO) 102 is coupled to an LNG carrier 104 by a hose 10 according to the present invention. The hose 10 carries LNG from the storage tank of the FPSO 102 to the storage tank of the LNG carrier ship 104. In FIG. 5A, the hose 10 is located above the sea level 106. In FIG. 5B, the hose 10 is immersed under the sea surface 106. In FIG. 5C, the hose 10 is floating near the sea surface. In each case, hose 10 carries LNG without any intermediate support. In FIG. 5D, the LNG carrier is connected to the storage facility 108 on the land base via the hose 10.
[0207]
The hose 10 can be used for many other applications besides those shown in FIGS. 5A-5C. The hose can also be used in cold storage and non-cold storage conditions.
[0208]
The present invention described above may be modified. For example, the tubular outer cylinder 20 may be disposed outside the outer wire 24. The hose 10 may also include additional reinforcing layers 14, 18, a sealing layer 16, and / or a tubular outer cylinder 20. One or more or even all of the sealing layers 18a may be a polymer coated metal film or a metal coated polymer film. Similarly, one or more or even all of the sealing layers 18b may be a polymer coated metal film or a metal coated polymer film.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing main stresses that a hose according to the present invention receives during use.
FIG. 2 is a schematic sectional view of a hose according to the present invention.
FIG. 3 is a cross-sectional view showing the arrangement of reinforcing layers of the hose according to the present invention.
FIG. 4A is a cross-sectional view showing the arrangement of the axially reinforced outer cylinder of the hose according to the present invention when the axially reinforced outer cylinder is in a relaxed state, and FIG. Sectional drawing which shows arrangement | positioning of the tubular axial reinforcement outer cylinder of the hose which concerns on this invention when it exists in the clamped state.
FIGS. 5A, 5B, 5C and 5D show four applications of the hose according to the invention.
FIG. 6 is a cross-sectional view showing a sealing layer of a hose according to the present invention.
7 is a more detailed cross-sectional view showing the insulating layer of the hose of FIG. 2;
FIG. 8 is a schematic sectional view of a terminal part of a hose according to the present invention.
[Explanation of symbols]
10 ... hose, 12 ... tubular body, 14 ... inner reinforcing layer,
14a: fibers arranged in the warp direction W
14b ... fibers arranged in the weft direction F, 16 ... outer reinforcing layer,
18 ... sealing layer, 18a ... first polymer film layer,
18b ... second polymer film layer, 20 ... tubular outer cylinder,
20a, 20b ... fiber, 21 ... reinforcing layer, 22 ... inner wire, 24 ... outer wire,
26 ... insulating layer, 26a ... inner layer (polyurethane layer),
26b ... Basaltic cloth layer, 26c ... UHMWPE layer, 26d ... Pressure layer,
28 ... Space, 102 ... FPSO, 104 ... LNG carrier, 106 ... Sea surface, 108 ... Storage equipment, 200 ... Terminal parts, 202 ... Inside member,
202a ... hose terminal, 202b ... tail part,
202c, 212a, 212b, 214a ... hole, 202d, 208a ... groove,
202e, 208b ... projection, 204 ... sealing ring, 206 ... split ring,
208 ... Hose coupling member, 210 ... Load transfer member,
212 ... Plate (terminal member), 214 ... Disk-shaped plate,
216: Load transfer rod, 220: Fixing bolt.

Claims (49)

A hose having a tubular body of soft material disposed between a spirally wound inner wire and a spirally wound wire;
The tubular body has a role of transporting fluid through the hose and preventing leakage of fluid through the tubular body, and the tubular body has two layers of reinforcing layers with a sealing layer interposed therebetween. Have
Furthermore, when the tubular body is subjected to tension in the axial direction, a shaft reinforcement means adapted to reduce deformation of the tubular body has an axis strengthening means in the form of a generic tubular braid, The shaft strengthening means includes a general-purpose tubular outer cylinder formed from a sheet of material defined in a tubular shape, and the tubular outer cylinder is perfect in its tubular shape when subjected to axial tension. Can maintain a radial inward force on at least a portion of the tubular body when the axial strengthening means is subjected to axial tension,
The hose characterized in that the fracture strain of the tubular body and the shaft reinforcing means is in the range of 1% to 10%. The hose of claim 1 , comprising two or more of the tubular outer cylinders. The hose according to claim 1 or 2 , wherein the braid has a triaxial shape. The hose according to any one of claims 1 to 3 , further comprising a reinforcing layer between the shaft reinforcing means and the outer grip member. The hose according to claim 4 , wherein the tubular main body, the shaft reinforcing means, and the reinforcing layer are all made of the same polymer material. The reinforcing layer or each reinforcing layer has a woven fabric formed of fibers arranged in the warp and weft directions, and the warp direction is at an angle of less than 20 ° with respect to the longitudinal axis of the hose. 6. The hose according to any one of claims 1 to 5 , wherein the hose is disposed in the middle. The hose according to claim 6 , wherein the reinforcing layer is arranged such that the warp direction is an angle of less than 10 ° with respect to the longitudinal axis of the hose. The hose according to any one of claims 4 to 7 , wherein the reinforcing layer or each reinforcing layer contains ultra high molecular weight polyethylene. The hose according to any one of claims 1 to 8 , wherein the shaft reinforcing means includes ultra high molecular weight polyethylene, aramid fiber, or polyester fiber. The hose according to any one of claims 1 to 9 , wherein the sealing layer includes ultra high molecular weight polyethylene or a copolymer of hexafluoropropylene and tetrafluoroethylene. The hose according to any one of claims 1 to 10 , wherein the sealing layer further includes at least one layer partially or wholly containing a metal or a metal oxide. The encapsulating layer includes at least two polymer films, one of the films is made of a first polymer, and the other of the films is a second that is different from the first polymer. Made of polymer,
One of the film, the harder than the other film, thereby, different yield strain is any one of the claims 1, characterized in that appearing in the nature of the material at the operating temperature and pressure 9 The hose according to item. The hose according to claim 12 , wherein the outer film is harder than the inner film. The hose according to any one of claims 12 and 13 , wherein the polymer film of the sealing layer contains polyester, polyamide, polyolefin, or fluoropolymer. 15. A hose according to any one of claims 12 to 14 , wherein one of the polymer films of the sealing layer comprises a polyolefin and the other polymer film comprises a fluoropolymer. . 16. A hose according to any one of claims 14 or 15 , wherein one of the polymer films of the sealing layer comprises highly oriented ultra high density polyethylene. 17. A hose according to any one of claims 14 to 16 , wherein one of the polymer films of the sealing layer comprises a copolymer of hexafluoropropylene and tetrafluoroethylene. The sealing layer includes a plurality of layers each made of the polymer film, and in the plurality of layers, the first polymer film and the second polymer film are alternately arranged over the thickness of the sealing layer. The hose according to any one of claims 12 to 17 , wherein the hose is formed. The metal or metal oxide layer is a layer of a metal or metal oxide film, a polymer-coated metal or metal oxide film, or a polymer film metal-coated with a metal or metal oxide. 19. A hose according to any one of claims 12 to 18 , characterized in that The hose according to claim 1 , further comprising an insulating layer. And a cured resin base provided around the outer wire, the outer wire being attached to the resin base to limit relative movement between the outer wire and the remainder of the hose. The hose according to any one of claims 1 to 19 , wherein at least a part of the hose is embedded. The hose according to claim 21 , wherein the uncured resin forming the resin base material is a material that can be applied to the tubular member in a liquid form. The hose according to any one of claims 21 and 22 , wherein the resin base material is polyurethane. The hose according to any one of claims 21 to 23 , further comprising an insulating layer comprising a cloth made of basaltic fibers. 25. The hose according to claim 24 , further comprising a pressure layer that pressurizes the basaltic cloth around the basaltic cloth. The hose according to claim 25 , wherein the pressure layer includes ultra high molecular weight polyethylene. 27. A hose according to any one of the preceding claims , further comprising a layer of plastic material around the tubular member, the plastic material containing gas bubbles therein. 28. A hose according to claim 27 , wherein the plastic material is polyurethane. The plastic material, on a surface of said tubular body, and spraying the plastics material in liquid form, then, is cured by standing, claims, characterized in that applied to the tubular body The hose according to any one of 27 and 28 . 30. Hose according to any one of claims 27 to 29 , wherein the gas bubbles are introduced by injecting the gas into the plastic material while in the form of a liquid before spraying. . 31. A hose according to any one of claims 27 to 30 , further comprising a further layer of plastic material provided on the gas-containing plastic material and containing no gas bubbles. 32. A hose according to claim 31 , wherein the further layer of plastic material is polyurethane. 33. A hose according to any one of claims 27 to 32 , wherein the overall specific gravity of the hose is less than 0.8. An inner member adapted to be disposed at least partially within the hose, and sealing at least a portion of the tubular body surrounding the entire circumference between the sealing member and the inner member. A shaft on the hose around the sealing member to reduce or eliminate an axial load on the hose between the sealing member and the inner member and the fitted sealing member 34. A hose according to any one of claims 1 to 33 , further comprising a terminal component comprising separate load transfer means adapted to transmit a directional load. The inner member is substantially cylindrical and the sealing member has a ring shape adapted to receive the inner member therein, whereby the tubular body is configured to receive the inner member. 35. The hose of claim 34 , wherein the hose can be secured between an outer surface of the ring and an inner surface of the ring. The sealing member includes an inner sealing ring, according to claim 34, wherein said to have an outer split ring that can tighten the sealing ring to engage with said inner member and said tubular body or 35. The hose according to any one of 35 . The hose according to claim 36 , wherein the split ring is made of stainless steel, and the sealing ring is made of polytetrafluoroethylene. The load transfer means includes a hose engagement member, a load transmission member, and a terminal member fixed to the inner member, and the arrangement of the sealing member includes the load transmission member and the terminal member. 38. The device according to any one of claims 34 to 37 , wherein the hose engaging member and the terminal member are arranged between each other and are connected through the load transmitting member. The hose described. The hose engagement member is adapted to engage the hose such that at least a portion of the axial force in the hose is transmitted from the hose to the hose engagement member. The hose according to claim 38 . 40. In one of claims 38 or 39 , each of the inner member and the hose engaging member has a portion formed to receive an inner wire and an outer wire of the hose. The hose described. The load transfer member has a load transfer plate having a hole adapted to receive the hose passing therethrough, the load transfer plate having a surface engageable with the hose engaging member. 41. A hose according to any one of claims 38 to 40 , whereby a load can be transmitted from the hose engagement member to the load transfer plate. Said load transfer member further claims, characterized in that it comprises a fixed load transfer rod between the load transfer plate and the terminal member in order to transmit the load to the terminal member from the load transfer plate 41. The hose according to 41 . The inner member has a hose terminal adapted to extend inside the terminal part of the hose, and a tail part separated from the hose terminal,
The terminal member is disposed on one side of the sealing member adjacent to the tail portion, and the hose engagement member is disposed on the other side of the sealing member adjacent to the hose terminal. 43. The hose according to any one of claims 34 to 42 , wherein: (A) winding a wire around a tubular mandrel to form an inner coil;
(B) to prepare a tubular body formed of sheet material, wrapping the sheet material around the tubular mandrel and the inner coil;
(C) covering the free end of the mandrel with a shaft reinforced outer cylinder in the form of a general tubular braid so that the mandrel extends into the shaft reinforced outer cylinder, and then at least partially covering the tubular body. Pulling the shaft reinforced outer cylinder along the mandrel to cover, the shaft reinforced outer cylinder is adapted to reduce deformation of the tubular body when the tubular body is subjected to axial tension. And the axially reinforced outer cylinder is adapted to exert a radial inward force on at least a portion of the tubular body when subjected to axial tension;
(D) winding a wire around the shaft-reinforced outer cylinder to form an outer coil;
(E) fixing the end of the hose produced in step (d); and
(F) removing the hose from the mandrel;
44. The method for manufacturing a hose according to any one of claims 1 to 43 , comprising each step. 45. The method of claim 44 , wherein the coil and the sheet material are applied under tension. 46. The method according to claim 44 or 45 , wherein the sheet material in step (b) has two reinforcing layers with a sealing layer sandwiched therebetween. An inner reinforcing layer in the form of a sheet is spirally wound around the inner coil and the mandrel, after which the sealing layer in the form of a sheet spirals around the inner reinforcing layer The method of claim 46 , wherein an outer reinforcing layer in the form of a sheet is wound around the sealing layer. The inner and outer coils are applied to a helical structure having substantially the same pitch, and the coil position of the outer coil is offset from the coil position of the inner coil by half the pitch length. 48. A method according to any one of claims 44 to 47 , characterized in that: In addition, the following steps:
(G) applying a curable breathable liquid resin on the outer wire;
(H) curing the resin to form a solid plastic coating containing gas bubbles therein;
49. A method according to any one of claims 44 to 48 , comprising:

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