WO2010001111A2

WO2010001111A2 - Improvements relating to hose

Info

Publication number: WO2010001111A2
Application number: PCT/GB2009/001639
Authority: WO
Inventors: Rodrigue Akkari; Chuon-Szen Ong; Steve Rossiter
Original assignee: Bhp Billiton Petroleum Pty Ltd
Priority date: 2008-06-30
Filing date: 2009-06-30
Publication date: 2010-01-07
Also published as: WO2010001111A3; GB0811967D0

Abstract

A mandrel for manufacturing hose, comprising a mandrel body, around which the hose may be arranged, and means for adjusting the diameter of the mandrel body.

Description

1MPROVEMENTS RELATING TO HOSE

This invention relates to hose, and more particularly relates to long length hose, and to a method and apparatus for making it. The invention is especially concerned with hose which can be used in cryogenic conditions.

Typical applications for hose involve the pumping of fluids from a fluid reservoir under pressure. Examples include supplying of domestic heating oil or LPG to a boiler; transporting produced oilfield liquids and/or gases from a fixed or floating production platform to the cargo hold of a ship, or from a ship cargo hold to a land-based storage unit; delivering of fuel to racing cars, especially during refuelling in formula 1 ; and conveying corrosive fluids, such as sulphuric acid.

It is well known to use hose for the transport of fluids, such as liquefied gases, at low temperature. Such hose is commonly used to transport liquefied gases such as liquefied natural gas (LNG) and liquefied propane gas (LPG). Many applications of hose require the hose to be supported along its length. This especially applies to the transport of the produced liquids and/or gases mentioned above. Without additional support, conventional hose is often incapable of supporting its own weight, or the weight of the fluid contained therein.

Three main types of hose exist that are used for large bore applications for transferring fluids at elevated pressure (e.g. at least 2barg). These are:

1. Rubber (rubber wraps vulcanised to form the hose body).

2. Bellows (convoluted steel tube).

3. Composite (films and fabrics between two helical wires). The present invention is directed to composite hoses. Rubber hoses differ from composite and bellows hose in that they do not have a steel component on the inner surface.

Rubber hoses are typically manufactured by wrapping numerous layers of rubber materials and some steel and fabric layers around a mandrel coated with a release agent. Some Rubber Hoses use an extruded rubber inner liner on a mandrel as the innermost layer and then wrap after that. Other rubber hoses include an interlocked carcass inside the liner, for collapse resistance. The complete structure is then vulcanised thus bonding the rubber wraps together. The complete hose assembly, including the end fittings which are also on the mandrel and are wrapped into the hose body structure, is removed from the mandrel by pulling and rotating. The hose and mandrel are supported by a series of rollers during this extraction process. Rubber hoses are typically made in lengths of up to 12m and bores of up to at least 1.2m.

In essence, the traditional method of manufacture for the bellows and composite hose is the same as that of a rubber hose. A bellows hose is formed in sections supported on steel mandrel and if insulating or protective layers are required these will be wrapped around the bellows tube. A composite hose is traditionally formed by a steel wire being wound helically onto a steel mandrel followed by a number of film and fabric layers. This is then formed into the hose body by the application of a second helical wire.

Both bellows and composite hoses are widely available in bores of up to 200mm and in lengths of up to about 30m. However it is difficult to manufacture and extract a large bore hose, greater than 400mm, of either of these types in a reasonable length, greater than 10m, using the traditional manufacturing techniques. This is not the case with rubber hoses as they do not have an inner steel component.

Both bellows and composite hoses are currently manufactured on steel mandrels, which for small diameters works well and is the industry standard; but as the diameter increases the effect of friction is increased dramatically. The surface area of contact between the hose and the mandrel increases linearly with diameter but the weight of the mandrel increases approximately with the square of the diameter. The product of these two factors is the friction between the hose and mandrel as during extraction the weight of the mandrel is taken through the hose. Other factors affecting the ease of extraction include:

Galling between the steel mandrel and the steel wire. • The coefficient of friction between the two materials.

The weight of the hose.

The use of supporting rollers used to control mandrel deflection. Attempts to manufacture hoses using the traditional techniques have resulted in hoses that have the required bore but are too short, or have the required bore and length but have been damaged during extraction. It has also been the case that the mandrel has become damaged during extraction and so in an industrial setting this process would be impractical and uneconomic.

Composite hose is described in many prior art documents, including, for example, EP-0076540A1 and WO01/96772. As discussed above, this type of hose is characterised by an inner metallic inner structure which is difficult to remove from the mandrel during the manufacturing process. As a result there is a practical limit on the size of hose which can be produced in the prior art, while at the same time retaining the ability to operate in hostile environments, such as in conditions of low and high temperature; and in marine applications.

GB2303574, DE2948416, JP08336845, JP08011138 and JP03075132 disclose a method of making hose or tubing, but they do not disclose the manufacture of bellows hose. Bellows hose is exclusively manufactured on a metallic mandrel; the mandrel may consist exclusively of the stainless steel or may be clad with stainless steel. In 2005, a carbon steel mandrel might typically cost about £25,000 and in its working lifetime it would be capable of being used to manufacture about 25-30 individual hoses. However, there is a problem with carbon steel mandrels, as the metallic inner member of the hose is often made of stainless steel. When such hose is manufactured using a carbon steel mandrel, part of the carbon steel can be transferred to the surface of the stainless steel inner member; this causes a site for corrosion of the inner member, which can lead to rapid failure in extreme environments. For this reason, the mandrel used in the manufacture of bellows hose and composite hose usually has to be made of stainless steel. A stainless steel hose costs three to four times as much as a carbon steel mandrel.

WO2007/129094 describes a method of manufacturing composite hose, which involves using a non-metallic mandrel in place of the conventional stainless steel mandrel. WO2007/129096 describes a method of manufacturing bellows hose, which involves using a non-metallic mandrel in place of the conventional stainless steel mandrel.

Reference is also made to SU963609, US5327765, US4352285, GB1398319, GB2031330, GB1287279 and RU2200661.

Although the use of non-metallic mandrels leads to considerable advantages, there is still a problem in removing the hose from the mandrel. A number of techniques for removing the hose from the mandrel were described in WO2007/129094 and WO2007/129096. We have now made a further improvement in the removal of the hose from the mandrel. -A-

According to one aspect of the invention there is provided a mandrel for manufacturing hose, comprising a mandrel body, around which the hose may be arranged, and means for adjusting the diameter of the mandrel body. The adjustment of the diamater is advantageously an increase and a decrease in the diameter of the hose.

The means for adjusting the mandrel body has two key advantages. First, it is possible to set the mandrel to the correct diameter required for the hose. Thus, instead of having to have a separate mandrel for each desired hose diameter, it is possible to use a single mandrel for all, or at least a wide variety of, hose diameters. Second, it is possible to reduce the mandrel diameter after the hose has been formed, to facilitate removal of the hose from the mandrel. This has the advantage that the hose can be removed from the mandrel without destroying or damaging the mandrel, thereby facilitating re-use of the mandrel.

Preferably, the mandrel body cross section comprises at least two relatively movable sections, more preferably at least three relatively movable sections and most preferably four relatively movable sections. If desired, there may be more than four relatively movable sections, e.g., five, six, seven, eight or more relatively movable sections.

Preferably, each relatively movable section extends axially along the length of the mandrel body, the sections in combination making up the external surface of the mandrel body.

Thus, the arrangement is such that outward movement of the movable sections causes an expansion in the mandrel diameter, while inward movement of the movable sections causes a reduction in the mandrel diameter. The means for adjusting the diameter of the mandrel body preferably comprises one or more adjustable members movable between an expanded position, in which the movable sections are moved by the adjustable members to the desired hose inner diameter, and a retracted position, in which the movable sections are moved by the adjustable members to a diameter smaller than the desired hose inner diameter, whereby the hose can be removed from the mandrel.

Each movable section of the mandrel may be provided with a respective adjustable member to facilitate movement of the movable sections. The movement of each movable section may be independent of the movement of the other sections, or the arrangement may be such that each movable section is moved by an identical distance.

The adjustable members may be operated, for example, mechanical, hydraulic or electrical. In an embodiment, the mandrel further includes a drive shaft capable of applying a turning force to the mandrel body during formation of the hose on the mandrel body, to facilitate wrapping of the hose parts around the body.

In a preferred embodiment, the mandrel further comprises two plugs fixedly disposed at each end of the mandrel body, the plugs being connected to the draft shaft, whereby torque applied to the drive shaft is transmitted to the plugs to turn the mandrel body. The drive shaft preferably projects outwardly from the plugs and mandrel at at least one end of the mandrel body.

A drive means, such as a motor, e.g. an electric motor, may be provided to apply torque to the drive shaft. In an embodiment, the rotation of the drive shaft may be used to apply tension to the cutting member. In this embodiment, after the hose has been formed, the ends of the cutting member may be fixed, whereby rotation of the drive shaft causes rotation of the mandrel and causes the cutting member to cut the mandrel.

The use of the movable sections provides a modular structure to the mandrel, because if one of the sections becomes damages it is possible to replace just the single damaged section. Furthermore, the length of the mandrel can be adjusted by attaching more than one section end to end.

The outer surface of the sections can be protected from abrasive damage by the use of a wear resistant coated thereon. For example, a Teflon (RTM) tape would be suitable, and is available in thicknesses from less than 1 mm upwards.

According to another aspect of the invention there is provided a method of manufacturing a hose using a mandrel as described above.

According to another aspect of the invention there is provided a method of making a hose, comprising adjusting a mandrel diameter to a desired hose diameter, forming the hose on the mandrel, and removing the hose from the mandrel.

Advantageously, the step of removing the hose from the mandrel is achieved by reducing the diameter of the mandrel.

According to another aspect of the invention, there is provided a method of removing a hose from a mandrel, comprising reducing the diameter of the mandrel and removing the hose from the reduced-diameter mandrel.

It should be noted that only a small reduction in mandrel diameter may be sufficient to facilitate easy extraction of the hose. Thus, less than or equal to around 10 mm, 5 mm or even 2 mm will usually be sufficient.

In one embodiment the hose is of the type known as composition hose, which comprises a tubular hose portion extending continuously between two end fittings, wherein said hose portion comprises a tubular body disposed between inner and outer gripping members and the tubular body comprises at least two layers and includes at least one sealing layer and at least one reinforcing layer, wherein

In one embodiment the composite hose comprises a tubular hose portion extending continuously between two end fittings, wherein said hose portion comprises a tubular body disposed between inner and outer gripping members, wherein the tubular body comprises at least one sealing layer and at least one reinforcing layer, and wherein the internal diameter of the hose portion is at least 200mm and the length of the hose portion is at least 30m.

It will be appreciated that the hose portion extends continuously between the end fittings. Thus, the hose according to the invention is distinct from prior art hose comprising shorter lengths of hose which are attached together in sequence by attaching the end fittings together.

In a preferred embodiment, the length of the hose portion is at least 31m, more preferably at least 32m. The hose portion is desirably at least 35m in length. The length of the hose portion may be much longer than 30m, depending on the requirements. Thus, the hose portion might have a length of up to 50m or even up to 60m. The length of the hose portion will typically lie within the ranges discussed above, subject to the minimum of at least 30m.

The inner diameter of the hose portion is preferably at least 100mm, or at least 150mmm, or at least 200mm, or at least 250mm, more preferably at least 300mm, and still more preferably at least 350mm and most preferably at least 400mm. In accordance with preferred embodiments of the invention, the hose portion inner diameter may be at least 450mm, at least 500mm, at least 550mm or at least 600mm. It is unlikely to be desirable for the hose portion diameter to exceed 750mm, and typically the hose portion diameter would not exceed 600mm. Most preferably the hose portion has a length of from 30m or 35m up to about 50m, in combination with an inner diameter from 200mm to 600mm, preferably from 300mm to 600mm, most preferably 400mm to 600mm.

In another embodiment, the composite hose comprises a tubular hose portion extending continuously between two end fittings, wherein said hose portion comprises a tubular body disposed between inner and outer gripping members, wherein the tubular body comprises at least one sealing layer and at least one reinforcing layer, and wherein the internal diameter of the hose portion is at least 300mm and the length of the hose portion is at least 5m. In a preferred embodiment, the length of the hose portion is at least 8m, more preferably at least 10m, more preferably at least 15m, still more preferably at least 20m, or at least 25m. In particularly preferred embodiments, the hose portion may be at least 30m in length. The length of the hose portion may be much longer than 30m, depending on the requirements. Thus, the hose portion might have a length of up to 50m or even up to 60m.

The inner diameter of the hose portion is preferably at least preferably at least 350mm and most preferably at least 400mm. In accordance with preferred embodiments of the invention, the hose portion inner diameter may be at least 450mm, at least 500mm, at least 550mm or at least 600mm. It is unlikely to be desirable for the hose portion diameter to exceed 750mm, and typically the hose portion diameter would not exceed 600mm.

Most preferably the hose portion has a length of from 8m or 10m up to about 50m, in combination with an inner diameter from 400mm to 600mm.

In the composite hose according to the invention the inner gripping member, is preferably a helical gripping member, and is most preferably a wire. Likewise, the outer gripping member, is preferably a helical gripping member, and is most preferably a wire. Typically the inner gripping member and/or the outer gripping member is a metal, preferably stainless steel.

The tubular body preferably comprises a sealing layer sandwiched between inner and outer reinforcing layers.

The hose portion advantageously also includes axial strengthening means which is adapted to exert a radially inward force on at least part of the tubular body when the axial strengthening means is subjected to axial tensioning. In a particularly advantageous embodiment the axial strengthening means is provided in the form of a generally tubular braid. In this specification the term "braid" refers to a material which is formed of two or more fibres or yarns which have been intertwined to form an elongated structure. It is a feature of braid that it can elongate when subjected to an axial tension. It is a further feature of braid that, when provided in a tubular form, its diameter will reduce when the braid is subjected to axial tension. Thus by providing a tubular braid around the tubular body, or within the structure of the tubular body, the braid will exert a radially inward force on at least part of the tubular body when subjected to axial tension. The braid is preferably in the form of a tubular sheath which is applied to the hose structure by pulling it over the components of the hose that have already been arranged on the mandrel.

The reinforcing layers and the sealing layer are preferably wrapped around the inner gripping member.

The hose may also include one or more additional reinforcing layers, along with one or more insulation layers, and one or more layers to improve the buoyancy of the hose. The hose may include one or more protective layers. Preferably there is at least one protective layer overlying the outer gripping member.

The most preferred composite hose for use in the present application is described in WO01/96772, WO 2004/044472 and WO 2004/079248, the contents of which are incorporated by reference. The structure of the hose may be substantially identical to the hose described in these publications, except that the present invention enables working hose to be produced which is longer and/or of greater diameter, owing to the improvements in the manufacturing process according to the invention. The end fittings for the hose may also be as described in the above three publications. Thus, according to another aspect of the invention there is provided a method of manufacturing composite hose comprising a tubular hose portion extending continuously between two end fittings, wherein said hose portion comprises a tubular body disposed between inner and outer gripping members and the tubular body comprises at least two layers and includes at least one sealing layer and at least one reinforcing layer, wherein said method comprises winding the inner gripping member around a non-metallic mandrel as described above, wrapping a first of the layers of the tubular body around the inner gripping member, wrapping a second of the layers of the tubular body around the first layer of the tubular body, winding the outer gripping member around the second reinforcing layer, applying a respective one of the end fittings to each end of the hose portion, reducing the diameter of the mandrel body, and removing the mandrel from the hose.

The end fittings are preferably applied before removing the mandrel from the hose, although they may in some circumstances be applied after removing the mandrel from the hose ; or one end fitting can be applied before removal of the mandrel, and the other can be applied after removal.

In another embodiment, the hose is of the type known as bellows hose, which comprises a tubular hose portion extending continuously between two end fittings, wherein said tubular hose portion comprises a plurality of tubular corrugated or convoluted sections secured end to end and at least one protective and/or reinforcing layer disposed around said corrugated or convoluted sections.

In one embodiment, the bellows hose comprises a tubular hose portion extending continuously between two end fittings, wherein said tubular hose portion comprises a plurality of tubular corrugated or convoluted sections secured end to end and at least one protective and/or reinforcing layer disposed around said corrugated or convoluted sections, wherein the internal diameter of the hose portion is at least

200mm and the length of the hose portion is at least 30m.

In a preferred embodiment, the length of the hose portion is at least 31m, more preferably at least 32m. The hose portion is desirably at least 35m in length. The length of the hose portion may be much longer than 30m, depending on the requirements.

Thus, the hose portion may have a length of up to 50m or even up to 60m. The length of the hose portion will typically lie within the ranges discussed above, subject to the minimum of at least 30m. The inner diameter of the hose portion is preferably at least 100mm, or at least

150mmm, or at least 200mm, or at least 250mm, more preferably at least 300mm, and still more preferably at least 350mm and most preferably at least 400mm. In accordance with preferred embodiments of the invention, the hose portion inner diameter may be at least 450mm, at least 500mm, at least 550mm or at least 600mm. It is unlikely to be desirable for the hose portion diameter to exceed 750mm, and typically the hose diameter would not exceed 600mm.

Most preferably the hose portion has a length of from 30m or 35m up to about

50m, in combination with an inner diameter from 200mm to 600mm, preferably from 300mm to 600mm, most preferably 400mm to 600mm.

In another embodiment, the bellows hose comprises a tubular hose portion extending continuously between two end fittings, wherein said tubular hose portion comprises a plurality of tubular corrugated or convoluted sections secured end to end and at least one protective and/or reinforcing layer disposed around said corrugated or convoluted sections, wherein the internal diameter of the hose portion is at least 300mm and the length of the hose portion is at least 5m.

In a preferred embodiment, the length of the hose portion is at least 8m, more preferably at least 10m, more preferably at least 15m, still more preferably at least 20m, or at least 25m. In particularly preferred embodiments, the hose portion may be at least 30m in length. The length of the hose portion may be much longer than 30m, depending on the requirements. Thus, the hose portion may have a length of up to 50m or even up to 60m.

The inner diameter of the hose portion is preferably at least preferably at least 350mm and most preferably at least 400mm. In accordance with preferred embodiments of the invention, the hose portion inner diameter may be at least 450mm, at least 500mm, at least 550mm or at least 600mm. It is unlikely to be desirable for the hose portion diameter to exceed 750mm, and typically the hose portion diameter would not exceed 600mm. Most preferably the hose portion has a length of from 8m or 10m up to about

50m, in combination with an inner diameter from 400mm to 600mm.

The bellows hose according to the invention comprises at least a tubular bellows and end fittings. The tubular bellows has a convoluted or corrugated profile. The convolutions or corrugations may be sinusoidal, U-shaped or shaped like the Greek letter omega, Ω. The convolutions may be circumferential, or may be arranged in a spiral. In general, only the sinusoidal convolutions are arranged in a spiral.

In an embodiment, the bellows hose includes a second tubular bellows arranged around the first bellows.

The bellows hose may also include additional strengthening and/or sealing layers and/or insulation layers. Typically an armoured layer is provided as the outer layer of the hose.

Preferably an end fitting is provided at each end of the hose.

When two tubular bellows are provided, insulation may be provided between the two layers. In addition, or instead, a vacuum may be provided in the space between the two layers, in order to provide insulation.

The first and/or second tubular bellows may be made of metal, preferably stainless steel. Thus, according to another aspect of the invention there is provided a method of manufacturing bellows hose comprising a tubular bellows and an end fitting at each end of the hose, wherein said method comprises arranging the bellows around an inner non-metallic mandrel, reducing the diameter of the mandrel body, and removing the mandrel from the hose. The end fittings are preferably applied before removing the mandrel from the hose , although they may in some circumstances be applied after removing the mandrel from the hose; or one end fitting can be applied before removal of the mandrel, and the other can be applied after removal.

The inner diameter of the hose portion (composite or bellows hose) according to the invention corresponds to the outer diameter of the non-metallic mandrel on which it was formed. The length of the hose portion corresponds to the distance between the end fittings immediately after manufacture of the hose. It should also be noted, that owing to the nature of the materials and the manufacturing process, the hose dimensions would usually be subject to a tolerance of about +/- 3%. It is important to understand that the hose formed in accordance with the invention is a working composite or bellows hose having a length and/or diameter which is greater than that which has been possible in accordance with the prior art. There may be examples in the prior art of hose which has a diameter and/or length within the ranges described above, but such hoses are not working hoses, i.e., they would not be able to operate under their normal operating pressure without leaking.

The hose according to the invention may have a high or low working temperature, including a cryogenic working temperature.

For example, when the hose is intended for use at high temperatures, the working temperature of the hose may be at least 4O⁰C, or at least 60⁰C, or at least 80⁰C or at least 10O⁰C, up to a maximum of 200°C or 300⁰C.

When the hose is intended for use at low temperatures, the working temperature of the hose may be from 0°C down to -200⁰C or -220⁰C. Typically the working temperature is -20⁰C or below, -40°C or below, -60°C or below, or -80⁰C or below. For cryogenic applications, the working temperature will typically be from -100⁰C to -170°C, -200°C or -220°C. A working temperature range from -100⁰C to -220°C is suitable for most cryogenic applications, including the transportation of LNG, liquid oxygen (bp - 183°C) or liquid nitrogen (bp -196⁰C). In general, the working pressure of the hose is be in the range from about 500 kPa gauge, or 1 ,00OkPa gauge, up to about 2,000 kPa gauge, or possibly up to about 2,500 kPa gauge. These pressures relate to the operating pressure of the hose, not the burst pressure (which must be several times greater).

The working volumetric flow rate depends upon the fluid medium, the pressure and the inner diameter. Working flowrates from 1 ,000 m³/h up to 12,000 m³/h are typical.

A preferred working temperature and pressure would be from -100°C to -200⁰C at a pressure from 50OkPa gauge, preferably 1 ,00OkPa gauge, up to 2,00OkPa gauge or 2,50OkPa gauge. The hose according to the invention can also be provided for use with corrosive materials, such as strong acids,

As mentioned above, the mandrel body is non-metallic. Preferably the mandrel is formed of a paper based material, a wood based material or a plastics polymer based material, such as high density polyethylene, or mixtures thereof. In one particularly advantageous embodiment, the mandrel is cardboard, i.e. a board made of paper pulp.

In the manufacture of composite hose, it is particularly important to ensure that the mandrel has sufficient radial stiffness to withstand the large crushing forces applied during the formation of the hose portion. Thus, it is advantageous that the mandrel has sufficient radial stiffness that the hose portions can be formed on the mandrel without causing any substantial change to the cross-sectional shape of the mandrel.

To achieve this, in one advantageous embodiment, the mandrel is formed of a material having a ratio of Young's Modulus (E) to density (p) in the range 0.1 to 10 GPa.m³/Mg (i.e. giga Pascal x metre³/megagram). Preferably the ratio of E/p is greater than 0.3 GPa.m³/Mg, more preferably greater than 0.5 GPa.m³/Mg, and most preferably greater than 0.8 GPa.m³/Mg. Preferably the ratio of E/p is less than 10 GPa.m³/Mg, more preferably less than 5 GPa.m³/Mg, and most preferably less than 3 GPa.m³/Mg. Thus, it will be appreciated that the most preferred range of E/p is from 0.8 to 3 GPa.m³/Mg. The values of E/p for cardboard and high density polyethylene, which are two materials particularly preferred for the mandrel, are about 1.2 and 1.0 GPa.m³/Mg respectively. The value of E/p for the prior art mandrel material, stainless steel, is about 20 GPa.m³/Mg. In some circumstances, it may be desirable to use composite materials, i.e., fibres disposed within a matrix, as the mandrel. Composite materials have a ratio of E/p close to stainless steel, but the density is much lower. Thus, in an alternative embodiment, the material of the mandrel has an E/p in the range 20 to 22 GPa.m³/Mg and a density in the range 1.0 to 3.0 Mg/m³. Typically, the composite material comprises carbon, glass or polymeric fibres disposed within a suitable polymeric matrix. Such materials make it possible to significantly reduce the mandrel weight without sacrificing strength.

It will, of course be appreciated that, while the mandrel is made of a non-metallic material, it is perfectly possible for the mandrel to include metallic or ceramic fillers. Thus the invention encompasses the use of a cardboard mandrel with a metallic or ceramic filler. The bulk of the mandrel, however, remains non-metallic.

The mandrel may be provided in one continuous length, or it may be provided in a plurality of mandrel sections of shorter length, which are assembled on site to form the completed mandrel. The purpose of this is to facilitate transport of the mandrel. The length of the mandrel will typically be approximately 1000 to 2000 mm longer than the length of the hose portion that it is desired to make on the mandrel. The outer diameter of the mandrel will typically be substantially identical to the inner diameter of the hose portion that it is desired to make on the mandrel. Thus, the mandrel will typically have an outer diameter of 200mm, or 300mm to 600mm. Advantageously, the mandrel is hollow. This feature enables the drive shaft to be disposed longitudinally within the mandrel. It also makes the mandrel easier to cut. When the mandrel is hollow, the thickness of the mandrel (i.e. the difference between its inner and outer diameter) would typically be about 10 mm to 25mm.

It is preferred that the mandrel body has a substantially cylindrical configuration. The preferred configuration for the mandrel is a hollow tube, most preferably a substantially cylindrical hollow tube.

As discussed above, the non-metallic mandrel body should be made of a material which is strong enough that it can properly support the hose during construction thereof. Furthermore, except for any coating that may be provided on the inner or outer surface of the mandrel, or any fillers (such as ceramic or metallic fillers) the entire mandrel is preferably made of the same non-metallic material.

The drive shaft is preferably secured to the or each plug, and desirably has a projecting end which can be connected to a drive motor, whereby rotation of the drive shaft causes rotation of the or each plug and thereby rotation of the mandrel. It is a preferred feature of the invention that the mandrel is rotated while part or all of the inner and/or outer structures are arranged in place on the mandrel. Preferably the drive motor is provided with a gearbox. In an alternative, the drive shaft may not be present, and the rotation of the mandrel may be driven by rotating one plug or both plugs (if present) using the drive motor.

Reference is now made to the accompanying drawings, in which:

Figure 1 is a schematic cross-sectional view of a composite hose made using the mandrel according to the invention;

Figures 2A, 2B, 2C and 2D show four applications of hose made using the mandrel according to the present invention;

Figure 3 is a schematic cross-sectional view of a bellows hose made using the mandrel according to the invention; Figure 4 is a perspective view of a mandrel for use in manufacturing hose, according to the invention;

Figure 5 is a side elevation, in cross-section, of the mandrel shown in Figure 3;

Figure 6 is an end cross-section of the mandrel shown in figures 4 and 5;

Figure 7 illustrates one embodiment of the mandrel according to the invention; Figures 8A and 8B illustrate another embodiment of the mandrel according to the invention; and

Figures 9A and 9B illustrate another embodiment of the mandrel according to the invention.

In Figure 1 a composite hose in accordance with the invention is generally designated 10. In order to improve the clarity the winding of the various layers in Figure 1 has not been shown.

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

The tubular body 12 and the tubular sheath 20 are disposed between an inner helically coiled wire 22 and an outer helically coiled wire 24. The inner and outer wires 22 and 24 are disposed so that they are offset from one another by a distance corresponding to half the pitch length of the helix of the coils.

An insulation layer 26 is disposed around the outer wire 24. The insulation layer may be a conventional insulating material, such as a plastics foam, or may be a material described in relation to Figure 7 in WO01/96772. The reinforcing layers 14 and 16 comprise woven fabrics of a synthetic material, such as UHMWPE or aramid fibres. The structure of suitable reinforcing layers is described in more detail in Figure 3 of WO01/96772.

The sealing layer 18 comprises a plurality of layers of plastics film which are wrapped around the outer surface of the inner reinforcing layer 14 to provide a fluid tight seal between the inner and outer reinforcing layers 14 and 16.

The hose 10 may include a further reinforcing layer (not shown) disposed between the sheath 20 and the outer wires 24. The further reinforcing layer may have similar characteristics to the sheath 20 and the tubular body 12.

The tubular sheath 20 is formed of two sets of fibres 20a and 20b which are braided to form a tubular braid. This is shown in Figures 4A and 4B of WO01/96772.

The sealing layer 18 is shown in greater detail in Figure 6 of WO01/96772. The sealing layer 18 comprises a plurality of layers of a film made of a first polymer (such as a highly oriented UHMWPE) interleaved with a plurality of layers of a film made of a second polymer (such as PFTE or FEP), the two polymers having a different stiffness. The layers are wrapped around the outer surface of the inner reinforcing layer 14 to provide a fluid tight seal between the inner and outer reinforcing layers 14 and 16. It will be appreciated that, if desired, the sealing layer 18 may be made of a single type of polymer, i.e., it does not have to include two or more different types of polymer.

The ends of the hose 10 may be sealed using the end fitting 200 shown in Figure 8 of WO01/96772 and/or as described in WO 2004/079248. The end fittings are illustrated schematically in Figure 1 and are designated with reference numeral 28.

Figures 2A to 2D show three applications for the hose 10. In each of Figures 2A to 2C a floating production, storage and offloading vessel (FPSO) 102 is linked to a LNG carrier 104 by means of a hose 10 according to the invention. The hose 10 carries LNG from a storage tank of the FPSO 102 to a storage tank of the LNG carrier 104. In Figure 2A, the hose 10 lies above the sea level 106. In Figure 2B, the hose 10 is submerged below the sea level 106. In Figure 2C₁ the hose 10 floats near the surface of the sea. In each case the hose 10 carries the LNG without any intermediate support. In Fig 2D the LNG carrier is linked to a land-based storage facility 108 via the hose 10. The hose 10 may be used for many other applications apart from the applications shown in figures 2A to 2D. The hose may be used in cryogenic and non- cryogenic conditions. In Figure 3 a bellows hose in accordance with the invention is generally designated 210.

The hose 210 comprises an inner tubular bellows 212 and an outer tubular bellows 214, each of which is provided with sinusoidal (or U-shaped or Ω shaped) corrugations. An insulation layer 216 is provided between the bellows 212 and 214. Furthermore, the space between the bellows 212 and 214 is placed in a vacuum, to further improve the insulation. An armoured layer 218 is provided around the outer bellows 214, to improve the insulation further. A pumping port 220 is provided for evacuating air from between the layers 212 and 214 in order to create the vacuum. The hose 210 also includes end fittings 222 at each end of the bellows hose (in Figure 1 , only one end fitting 222 is shown).

The bellows hose 210 may be used in the application shown in Figures 2A to 2D in place of the hose 10.

Figures 4 and 5 show a mandrel 300 according to the invention. The mandrel 300 can be used in the method according to the invention for making the hose according to the invention.

The mandrel 300 comprises a body 302 which has a length and diameter corresponding the desired length and diameter of the hose 10 and 200. The outer diameter of the mandrel body 302 corresponds to the inner diameter of the hose 10 or 200. The length of the mandrel body 302 is typically about 1-2m longer than the length of the hose 10 or 200. The mandrel body 302 has a substantially circular cross sectional shape, although other shapes may in some circumstances be desirable.

A torque transmitting plug 304 is secured to each end of the mandrel body 302, and a drive shaft 306 extends along the length of the mandrel between the plugs 304, and extends outwardly being the ends of the mandrel body 302. A drive motor 308, which may be an electric motor, is provided to drive rotation of the drive shaft 306. It will be appreciated that the drive shaft 306 can transmit torque to the plugs 304, which in turn can transmit torque to the mandrel body 302 to rotate it. Typically the mandrel body 302 will be rotated at a rate of 10-60 rpm.

The application of the hose 10 to the mandrel body 302 causes large radial forces to be directed against the mandrel. For example, the inner wire 22 is typically a non-flexible rigid steel material which has to be wound around the mandrel using a machine. Thus, it is important that the mandrel body 302 has sufficient radial stiffness that the hose portion can be formed on the mandrel without causing any substantial change to the cross-sectional shape of the mandrel. This is important, because if the mandrel deforms inwardly, the hose will be deformed, and will be more likely to fail during use. One way to select a mandrel of the appropriate radial stiffness is to select an material having an appropriate ratio of Young's Modulus (E) to density (p), as described above, but other techniques may be apparent to the skilled person.

Figure 6 is an end cross section of the mandrel body 302, which shows that the body is divided into four movable sections 400, 402, 404, and 406, each of which is secured to a respective adjustment member 410, 412, 414 and 416. The adjustment members 410, 412, 414 and 416 may be moved radially outwards to move the sections 400, 402, 404, and 406 radially outwards to a desired diameter. The adjustment members 410, 412, 414 and 416 may be moved radially inwards to move the sections 400, 402, 404, and 406 radially inwards to a desired diameter.

Figures 7 to 9 illustrate alternative means of driving the adjustment members 410, 412, 414 and 416. In Figure 7, a hydraulic/pneumatic system is illustrated, where hydraulic pressure is used to move pistons (i.e. the adjustment members) between the

"construction diameter" (i.e., the desired inner diameter of the hose) and the "extraction diameter" (i.e., the diameter at which the mandrel 300 can be removed from the hose).

In Figure 8, a mechanical system is illustrated, where mechanical pressure is used to move pistons (i.e. the adjustment members) between the "construction diameter" (i.e., the desired inner diameter of the hose) and the "extraction diameter" (i.e., the diameter at which the mandrel 300 can be removed from the hose).

In Figures 8A and 8B, a mechanical system is illustrated, where mechanical pressure is used to move pistons (i.e. the adjustment members) between the "construction diameter" (i.e., Figure 8A, the desired inner diameter of the hose) and the "extraction diameter" (i.e., Figure 8B, the diameter at which the mandrel 300 can be removed from the hose).

In Figures 9A and 9B, a mechanical system is illustrated, where mechanical pressure is used to move pistons (i.e. the adjustment members) between the

"construction diameter" (i.e., Figure 9A, the desired inner diameter of the hose) and the

"extraction diameter" (i.e., Figure 9B, the diameter at which the mandrel 300 can be removed from the hose).

The manufacture of hose using the mandrel 300 will now be described with reference to the composite hose 10. Initially, the mandrel 300 is set in place, and the adjustment members 410, 412, 414 and 416 are moved radially outwards to move the sections 400, 402, 404, and 406 radially outwards to a desired diameter. The drive motor 308 is operated to rotate the mandrel body 302 at the required rate. As a first step, the inner wire 22 is wound around the mandrel body 302, in order to provide a helical arrangement having a desired pitch. As noted above, the outer diameter of the mandrel body 302 corresponds to the desired internal diameter of the hose 10. The inner reinforcing layer 14 is then wrapped around the inner wire 22 and the support mandrel, such that warp direction W is set at the desired angle, α.

A plurality of layers of the plastics films 18a, 18b making up the sealing layer 18 are then wrapped around the outer surface of the inner reinforcing layer 14. Usually, the films 18 would have a length substantially less than the length of the hose 10, so that a plurality of separate lengths of the films 18 would have to be wound around the inner layer 14.

The outer reinforcing layer 16 is then wrapped around the sealing layer 18, such that the warp direction W is set at the desired angle (which may be α, or may be some other angle close to α). The tubular axial strengthening sheath 20 is drawn over the outside of the outer reinforcing layer 16. If desired, the further reinforcing layer 21 is then pulled over the sheath 20.

The outer wire 24 is then wrapped around the further reinforcing layer 21 , in order to provide a helical arrangement having a desired pitch. The pitch of the outer wire 24 would normally be the same as the pitch of the inner wire 22, and the position of the wire 24 would normally be such that the coils of the wire 24 are offset from the coils of the wire 22 by a distance corresponding to half a pitch length; this is illustrated in Figure 1 , where the pitch length is designated p.

A polyurethane resin may then be sprayed over the outer surface of the sheath

20 to form a resin coating over the sheath 20 and the outer wire 24. The resin may then be left to harden, in order to form the layer 26a. In addition, or instead, a profiled wrap as described in WO 2004/044472 may be provided around the outer surface of the sheath 20.

It will be appreciated that, during the wrapping steps described above, the mandrel body 302 is rotating, so each layer simply needs to be laid onto the body 302 in the desired place, at the desired angle to the longitudinal axis of the body 302. Any layers which comprise a sheath (such as the layer 20 and the further reinforcing layer) are drawn onto the mandrel and the underlying hose, and are pulled longitudinally to the correct position; rotation of the mandrel body 302 may be interrupted while any sheath layers are applied.

The ends of the hose 10 may be sealed by crimping a sleeve onto an insert inside the hose 10. This termination is generally applied after the hose 10 as been removed from the mandrel. To achieve this, the adjustment members 410, 412, 414 and 416 are moved radially inwards to move the sections 400, 402, 404, and 406 radially inwards to a diameter at which the hose 10 may be easily slid of the mandrel body 302. The ends of the hose 10 are sealed using the end fittings 28. When the end fittings 28 are in place, the hose 10 may be removed from the mandrel body 302.

It will be appreciated that the invention described above may be modified within the scope of the claims.

Claims

CLAlMS:

1. A mandrel for manufacturing a hose, comprising a mandrel body, around which the hose may be arranged, and means for adjusting the diameter of the mandrel body.

2. A mandrel according to claim 1 , wherein the mandrel body cross section comprises at least two relatively movable sections.

3. A mandrel according to claim 1 , wherein the mandrel body cross section comprises at least three relatively movable sections.

4. A mandrel according to claim 1 , wherein the mandrel body cross section comprises four relatively movable sections.

5. A mandrel according to claim 2, 3 or 4, wherein each relatively movable section extends axially along the length of the mandrel body, the sections in combination making up the external surface of the mandrel body,

6. A mandrel according to claim 2, 3, 4 or 5, wherein the arrangement is such that outward movement of the movable sections causes an expansion in the mandrel diameter, while inward movement of the movable sections causes a reduction in the mandrel diameter.

7. A mandrel according to any preceding claim, wherein the means for adjusting the diameter of the mandrel body preferably comprises one or more adjustable members movable between an expanded position and a retracted position.

8. A mandrel according to claim 7, when dependent upon any one of claims 2 to 6, wherein each adjustable member is secured to a respective movable sections whereby movement of the adjustable members controls the outer diameter of the mandrel body.

9. A mandrel according to any preceding claim wherein the adjustment means operates mechanically, hydraulically or electrically.

10. A method of manufacturing a hose using a mandrel according to any preceding claim.

11. A method of making a hose, comprising adjusting a mandrel diameter to a desired hose diameter, forming the hose on the mandrel, and removing the hose from the mandrel.

12. A method according to claim 11 , wherein the step of removing the hose from the mandrel is achieved by reducing the diameter of the mandrel.

13. A method of removing a hose from a mandrel, comprising reducing the diameter of the mandrel and removing the hose from the reduced-diameter mandrel.

14. A method of manufacturing composite hose comprising a tubular hose portion extending continuously between two end fittings, wherein said hose portion comprises a tubular body disposed between inner and outer gripping members and the tubular body comprises at least one sealing layer and at least one reinforcing layer, wherein said method comprises winding the inner gripping member around a mandrel body, wrapping a first of the layers of the tubular body around the inner gripping member, wrapping a second of the layers of the tubular body around the first layer of the tubular body, winding the outer gripping member around the second reinforcing layer, reducing the diameter of the mandrel body, removing the mandrel from the hose, and applying a respective one of the end fittings to each end of the hose portion either before or after removing the mandrel from the hose.

15. A method of manufacturing bellows hose comprising a tubular bellows and an end fitting at each end of the hose, wherein said method comprises arranging the bellows around an inner non-metallic mandrel, reducing the diameter of the mandrel body, removing the mandrel from the hose, and applying a respective one of the end fittings to each end of the hose either before or after removing the mandrel from the hose.

16. A mandrel substantially as herein described with reference to and as shown in the accompanying drawings.