Patent Publication Number: US-8112863-B2

Title: Method for securing wires of an armour layer of a flexible pipe body

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This is the U.S. National Stage of International Application No. PCT/GB2007/001444, filed Apr. 20, 2007, which in turn claims the benefit of Great Britain Application No. 0611977.0, filed Jun. 16, 2006. 
     BACKGROUND 
     The present invention relates to an apparatus and method for providing an end fitting for a flexible pipe. In particular, but not exclusively, the present invention relates to a method and apparatus for securing wires of at least one armour layer of a portion of flexible pipe body when the flexible pipe body is terminated in an end fitting. One or both of an inner collar member and/or outer collar member include grooves or slots for receiving one or more of the wires so as to help determine a position of those wires. 
     Traditionally flexible pipe is utilised to transport production fluids, such as oil and/or gas and/or water, from one location to another. Flexible pipe is particularly useful in connecting a sub-sea location to a sea level location. Flexible pipe is generally formed as an assembly of a portion of flexible pipe body and one or more end fittings. The pipe body is typically formed as a composite of layered materials that form a pressure-containing conduit. The pipe structure allows large deflections without causing bending stresses that impair the pipe&#39;s functionality over its lifetime. The pipe body is generally built up as a composite structure including metallic and polymer layers. 
     The end fittings of a flexible pipe may be used for connecting segments of flexible pipe together or for connecting them to terminal equipment such as a rigid sub-sea structures or floating facilities. As such amongst other varied uses, flexible pipe can be used to provide a riser assembly for transporting fluids from a sub-sea flow line to a floating structure. In such a riser assembly a first segment of flexible pipe may be connected to one or more further segments of flexible pipe. Each segment of flexible pipe includes at least one end fitting. 
     It is well-known that there are many varied problems associated with the provision of end fittings for ends of flexible pipe body. The end fittings must ensure both good fastening and good sealing. Particular problems occur when the various specific layers of the multi layer flexible pipe body are terminated. The flexible pipe body may include layers having very different material characteristics such as single polymer layers and/or interlocked metallic layers. The termination of each of these layers in an end fitting brings with it characteristic problems. For example, flexible pipe body typically includes a barrier layer formed generally as a polymer sheath or pressure sheath. Such a layer operates as a primary liquid retaining layer. To prevent rupture of such a layer or indeed any underlying layer under high pressure caused by the pressure of the transported fluid, an interlocked wire layer is often located outside the barrier layer. Armour layers formed by layers of wire may also be provided to sustain tensile loads and internal pressure. If a pressure armour layer is not supported along its length, it is possible for portions of the barrier layer or other such underlying layer to burst through under pressure and cause failure of the terminating structure. 
     When the wires of the armour layers are terminated they are bent away from a central axis of the flexible pipe body. During this process many wires are located in a small space when the flexible pipe body is terminated. This can be confusing to workmen terminating the flexible pipe body and can lead to error. 
     SUMMARY 
     It is an aim of the present invention to at least partly mitigate the above-mentioned problems. 
     It is an aim of embodiments of the present invention to provide an apparatus and method for providing an end fitting for a flexible pipe. 
     It is an aim of embodiments of the present invention to provide an end fitting for a flexible pipe in which an inner collar member and/or an outer collar member include one or more grooves in a contact surface. The grooves can be used to locate and/or lock in place wires of the armour layer at predetermined locations. 
     According to a first aspect of the present invention there is provided a method for securing wires of at least one armour layer of a portion of flexible pipe body, in an end fitting, comprising the steps of:
         bending wires of at least one armour layer away from an axis of the flexible pipe body at a predetermined location;   locating each wire of the armour layer in a respective groove formed in a contact surface of at least one of an inner collar member and an outer collar member of the end fitting; and   urging contact surfaces of said inner collar member and said outer collar member together to thereby lock wires of the armour layer in a fixed position at said predetermined location in said end fitting.       

     According to a second aspect of the present invention there is provided an apparatus for providing an outer collar member of a portion of flexible pipe body, comprising:
         a substantially cylindrical outer collar neck portion; and   an outer collar body portion extending outwardly from said neck portion at a first end thereof; wherein   said body portion comprises a curved support surface including a plurality of grooves in which wires of an armour layer of the flexible pipe body are at least partially locatable when the flexible pipe is mounted in an end fitting.       

     According to a third aspect of the present invention there is provided an apparatus for providing an inner collar member of a portion of flexible pipe body, comprising a substantial cylindrical inner collar neck portion; and
         an inner collar body portion extending outwardly from said neck portion at a first end thereof; wherein   said body portion comprises a curves support surface including a plurality of grooves in which wires of an armour layer of the flexible pipe body are at least partially locatable when the flexible pipe body is mounted in an end fitting.       

     Embodiments of the present invention provide an inner collar member and/or an outer collar member which includes a contact surface in which one or more grooves or slots are preformed. The slots are shaped to receive one or more of the wires so that when a user terminates the flexible pipe body a guide is provided to duly locate the wires. Advantageously grooves may be formed in both an inner collar member and outer collar member and these grooves will mate when brought together. In this way wires can not only be located but also locked in place at predetermined locations. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Embodiments of the present invention will now be described hereinafter, by way of example only, with reference to the accompanying drawings in which: 
         FIG. 1  illustrates a flexible pipe body; 
         FIG. 2  illustrates a riser assembly; 
         FIG. 3  illustrates an end fitting of a flexible pipe; 
         FIG. 4  illustrates an end fitting body; 
         FIG. 5  illustrates an inner collar member; 
         FIG. 6  illustrates a sealing ring; 
         FIG. 7  illustrates an outer collar member; 
         FIG. 8  illustrates an end fitting cut away; and 
         FIG. 9  illustrates guide grooves for armour wires. 
     
    
    
     DETAILED DESCRIPTION 
     In the drawings like reference numerals refer to like parts. 
     Throughout this specification reference will be made to a flexible pipe. It will be understood that a flexible pipe is an assembly of a pipe body and one or more end fittings in each of which an end of the pipe body is terminated.  FIG. 1  illustrates how a pipe body  100  is formed from a composite of layered materials that form a pressure-containing conduit. Although a number of particular layers are illustrated in  FIG. 1 , it is to be understood that the present invention is broadly applicable to composite pipe body structures including two or more layers. 
     As illustrated in  FIG. 1 , a pipe body typically includes an inner most carcass layer  101 . The carcass provides an interlocked metallic construction that can be used as the innermost layer to prevent, totally or partially, collapse of an internal pressure sheath  102  due to pipe decompression, external pressure, tensile armour pressure and mechanical crushing loads. 
     The internal pressure sheath  102  typically comprises a polymer layer that ensures internal-fluid integrity. It is to be understood that this barrier layer may itself comprise a number of sub-layers. 
     A pressure armour layer  103  is a structural layer with a lay angle close to 90° that increases the resistance of the flexible pipe to internal and external pressure and mechanical crushing loads. The layer also structurally supports the internal-pressure sheath and typically consists of an interlocked metallic construction. 
     The flexible pipe body may also include one or more layers of tape  104  and a first tensile armour layer  105  and second tensile armour layer  106 . Each tensile armour layer is a structural layer with a lay angle typically between 20° and 55°. Each layer is used to sustain tensile loads and internal pressure. The tensile armour layers are typically counter-wound in pairs. 
     The flexible pipe body also typically includes layers of insulation  107  and an outer sheath  108  which comprises a polymer layer used to protect the pipe against penetration of seawater and other external environments, corrosion, abrasion and mechanical damage. 
     Each flexible pipe comprises a segment of pipe body  100  together with an end fitting located at at least one end of the flexible pipe. An end fitting provides a mechanical device which forms the transition between the flexible pipe body and a connector. The different pipe layers as shown, for example, in  FIG. 1  are terminated in the end fitting in such a way as to transfer the load between the flexible pipe and the connector. 
       FIG. 2  illustrates a riser assembly  200  suitable for transporting production fluid such as oil and/or gas and/or water from a sub-sea location  201  to a floating facility  202 . For example, in  FIG. 2  the sub-sea location  201  is a sub-sea flow line. The flexible flow line  203  comprises a flexible pipe, wholly or in part, resting on the sea floor  204  or buried below the sea floor and used in a static application. The floating facility may be provided by a platform and/or buoy or, as illustrated in  FIG. 2 , a ship. The riser  200  is provided as a flexible riser, that is to say a flexible pipe connecting the ship to the sea floor installation. The flexible pipe includes two segments of flexible pipe body  205   1  to  205   2  and one junction  206  between adjacent segments of pipe body. 
     It will be appreciated that there are different types of riser, as is well-known by those skilled in the art. Embodiments of the present invention may be used with any type of riser, such as a freely suspended (free, catenary riser), a riser restrained to some extent (buoys, chains), totally restrained riser or enclosed in a tube (I or J tubes). Also it will be appreciated that embodiments of the present invention can be used for single segment risers having, for example, a single long length of pipe body terminated at one or both ends with an end fitting or to multi segment risers having more than one segment. 
     It will also be appreciated that whilst embodiments of the present invention may be applied to the provision of risers, embodiments are generally applicable to any instance when an end fitting must be used to terminate an end of a portion of flexible pipe body. 
       FIG. 3  illustrates an end fitting  300  for a flexible pipe. The end fitting  300  includes an end fitting body  301  which includes an internal bore  302  running along its length. The end fitting body is made from steel or some other such rigid material. At a first end of the end fitting body  301  the body defines an open mouth region  303  into which an end of a segment of flexible pipe body  100  is located and then terminated. At a further end of the end fitting body  301  is a connector  304 . This is formed as a substantially disk-like flared region of the end fitting body. The connector can be connected directly to a matching connector of a further end fitting body of an adjacent segment of flexible pipe. This can be done using bolts or some other form of securing mechanism. In such a configuration the end fittings would be located in a back-to-back arrangement. Alternatively the connector  304  may be connected to a floating or stationary structure such as part of a ship, platform or other structure to which the flexible pipe is to be secured. 
       FIG. 4  illustrates the end fitting body  301  in more detail. The open mouth region  303  is formed by the open rim  400  of the end fitting body. This rim defines a circular open mouth through which a flexible pipe body may be introduced. The inner surface  401  includes a first stepped region  402  provided to receive a barrier layer sealing ring when a flexible pipe body is located in the end fitting and a further stepped region  403  arranged to receive a further sealing ring for sealing ends of layers of the flexible pipe body. The remainder of the inner surface  401  defines a substantially smooth inner bore along which transportation fluid will flow in use. 
     The end fitting body  301  includes a fastening region  404  extending outwardly from the waist of the body to which further parts of the end fitting may be secured during process of terminating the of flexible pipe body in the end fitting. 
       FIG. 4B  illustrates an end elevation of the end fitting body in the third angle projection. 
     Returning to  FIG. 3 , the inner carcass  101  and barrier layer  102  are terminated by being cut at a particular location to provide an end  305  to the flexible pipe body. The sealing ring  306  is located at the end of the stepped region  403  of the end fitting body so as to help seal the ends of the carcass layer and barrier layer. 
     An inner collar  500  is illustrated more clearly in  FIG. 5 . The inner collar  500  is formed from a collar body  501  from which extends a neck  502 . The inner collar  500  has a central bore  503  having a cross section defined by an inner surface  504  of the inner collar. The collar body  501  and neck  502  are integrally formed although these parts may be separately made. At an end of the neck  502  an outer surface  505  is formed in a curved surface  506 . This curved surface has a radius of curvature selected to define a minimum radius of curvature of an inner tensile armour layer supported by the surface. This will be described hereinafter in more detail.  FIG. 5B  illustrates an end view of the inner collar from the right hand side in  FIG. 5  (third angle projection). The inner collar  500  is an integral piece which helps improve efficiency during a mounting/assembly process. It will be understood that the inner collar could be formed as several pieces according to embodiments of the present invention. 
       FIG. 6  illustrates sealing ring  600  which may be used to form a seal between an outer surface of the barrier layer  102  of the flexible pipe body and the end fitting body  301 . The ring may be a composite structure including metallic and elastomeric parts typically silicone based. The sealing ring  600  is a substantially annular ring shaped piece having a substantially rectangular body  601  which includes an abutment face  602 . As illustrated in  FIG. 3 , the abutment face  602  will abut with a portion of the rim formed by the body of the inner collar member. The sealing ring  600  also includes a wedge-like section  603  which has a smooth outer surface  604  arranged to engage with an inner engagement surface of the end fitting body. Part  605  of the inner surface of the wedge-like part of the sealing ring includes small projections. These projections help furnish a good seal by partially digging into the barrier layer outer surface. However, the projections are so small that micro-cracking of the material of the barrier layer is avoided when the sealing ring is driven into sealing engagement with the barrier layer. As the end fitting body  301  is drawn towards the inner collar member  500 , as will be described in more detail hereinafter, an engagement surface of the end fitting body engages with the surface  604  of the sealing ring. This tends to urge the sealing ring in a direction from left to right in  FIG. 3  until the abutment surface  602  meets with the surface of the inner collar body. Further movement to the right is then prevented. Further movement of the end fitting body  301  from left to right deforms the wedge-like portion of the sealing ring so as to urge the projections  605  into a close sealing configuration with the barrier layer  102  of the terminated flexible pipe body. 
       FIG. 7  illustrates an outer collar  700 . The outer collar  700  includes a substantially cylindrical neck region  701  which is tapered at a first end region  702  thereof. The tapered end  703  helps when the outer collar is slotted between selected layers of the flexible pipe body. Having a taper thus helps when the outer collar is driven between selected layers. In  FIG. 3  the outer collar is shown slotted between an outer sheath and an outer tensile armour layer  106 . It is to be understood that the flexible pipe body  100  illustrated in  FIG. 3  does not show all of the layers illustrated in  FIG. 1  for the sake of brevity. The outer collar  700  is an integral piece which helps improve efficiency during a mounting/assembly process. It will be understood that the outer collar member could be formed as several pieces according to embodiments of the present invention. 
     The outer collar  700  also includes a body portion  704  from which the neck extends. The body is turned outwardly with respect to the neck. An inner surface  705  of the neck  701  is generally cylindrical but towards an open mouth  706  the inner surface flares outwardly. This inner surface region  707  may be gently curved and advantageously will have a radius of curvature common to the radius of curvature of the curved outer surface  506  of the inner collar member. In this way when the tensile armour layers  106  of the flexible pipe body are bent away from the barrier layer at a selected location  708 , the outermost tensile armour layer may be bent against the curved surface  707 . The curved surface  707  thus determines a minimum radius of curvature of the tensile armour layer. A remainder length of the tensile armour layers is located in a cavity in the end fitting in which the wire will be terminated. This cavity is filled with epoxy as described hereinafter in order to lock the wires in position. 
     Referring again to  FIG. 3 , the end fitting  300  further includes a casing  307  which is secured via one or more bolts  308  or other such securing mechanism to the end fitting body. The casing acts as a housing and is sealed to the outer sheath  108  of the flexible pipe body via an outer sealing ring  309  of the type illustrated in  FIG. 6 . The outer casing  307  is first attached to the end fitting and then an end plate  310  is secured to the casing. As the end plate  310  is driven towards the housing to secure the plate to the housing, the plate drives the seal  309  in a direction right to left as shown in  FIG. 3 . The outer surface of the wedge-like part of the seal thus engages with a surface  311  of the casing which produces an inwards force urging the wedge-like portion of the seal ring into a sealing arrangement with an outer surface of the outer sheath  108 . 
     Ends  312  of the tensile armour layers  106  are terminated within a cavity  313  formed between an inner surface of the housing  307  and the end fitting body  301  and inner collar  500 . This cavity  313  can be filled with epoxy or some other flowable sealant so that the end structure is substantially solid. This also helps lock component parts of the end fitting in place to prevent component movement. 
       FIG. 8  illustrates the end fitting  300  shown in  FIG. 3  in cut-away form. As illustrated in  FIG. 8 , an end part of a segment of flexible pipe body  100  is input into one end of the end fitting  300 . At a remainder end of the end fitting  300  the connector  304  provides a rigid structure which may be bolted or otherwise secured to a corresponding connector of an adjacent end fitting or to some other structure to which the flowline formed by the flexible pipe is to be secured. The end of the flexible pipe  100  is terminated within the end fitting with the various layers of the multi-layer flexible pipe being terminated at specific points along the length of the end fitting. A number of seals are provided so as to prevent leakage of transportation fluid flowing along the pipe and end fitting bore. 
     A method for terminating a segment of flexible pipe body according to an embodiment of the present invention will now be described. The flexible pipe body  100  is to be terminated in an end fitting  300 . For this reason the end of the flexible pipe body is cut across at a desired length. Next various parts of the end fitting are threaded over the, at this stage, open end of the pipe. These parts include the, Jacket  307 , end plate (outer collar)  310 , and outer seal ring  311 . 
     Next the various layers making up the multi-layer flexible pipe are cut to selected lengths. For example, the outer sheath  108  is cut much shorter than the carcass  101  and barrier layer  102  whilst the tensile armour layers are cut even longer. Next the outer collar  700  is slotted into position at the open end of the flexible pipe body. For example, the neck of the outer collar may be slotted between the outer sheath and outer most tensile armour layer. Once slotted in position the outer collar is kept in place by pressure between the layers of the flexible pipe body. These squeeze the neck of the outer collar effectively locking it in place. The armour wires  312  are then bent outwardly away from their supporting role next to the barrier layer of the flexible pipe body. The bend occurs at a selected region  708 . As shown in  FIG. 3 , this region corresponds to the location of the curved surface formed on the inner surface of the body part of the outer collar. By bending the armour layers against this curved surface, a minimum radius of curvature of the wires is controlled so that over-bending does not occur. 
     Some preparation of the various sealing faces such as measurement of the surfaces and sanding down may then occur followed by a process of securing the inner collar  500  in a relative position to the outer collar  700 . This is may be achieved using long bolts  314  or some other such securing means. Part  500  can be manufactured from a single ring or a split ring (and bolted together) and may be secured in place using friction or other attachment mechanism such as bonding with epoxy resin adhesive or being bolted to the outer collar, typically using long bolts  314 . Once the armour layers have been bent away from being parallel to the barrier layer and the inner collar has been secured in place, a seal ring  600  is placed around the open end of the pipe. The end fitting body  301  is then moved towards the end of the body of the inner collar  500 . The action of drawing the end fitting body on to the pipe swages the inner seal ring  600  down on to the fluid barrier. 
     In this embodiment the inner collar is secured in place with sufficient force to minimise movement when the swaging process is undertaken. This has the advantage of controlling the location at which the seal ring is secured and thereby the relative position of all the other components. Positioning the body  301  in place then drawing the seal ring on to the body, through the action of an unsecured inner collar moving in direction B as the bolts  314  are tightened is not as advantageous. This is because the point at which the seal ring is secured is fixed relative to the other components: the location of the inner collar, relative to the other components, is not fixed prior to the swaging process. Furthermore though the inner seal ring is initially swaged in direction B, once it bites into the underlying polymer layer the inner seal ring remains fixed and the body  301  moves in direction A potentially crushing the insulator ring  305 . 
     The end fitting body  301  is then moved towards the end of the body of the inner collar  500 . As the end fitting is moved towards the flexible pipe, the flexible pipe may be held in a rigid position by the inner and outer collar. As the end fitting body is moved in a direction illustrated by arrow A in  FIG. 3 , an engagement surface formed as part of the shoulder  402  urges the sealing ring into an abutting relationship with the inner collar. Further movement from left to right, as shown in  FIG. 3 , causes the shoulder of the end fitting to urge the wedge-like portion of the seal ring inwards into a close sealing relationship with an outer layer of the barrier layer of the flexible pipe body. This energises the seal. The end fitting body  301  may then be bolted to the inner collar using bolts or some other securing mechanism. The free ends  312  of the armour wires are then bent into a position within the cavity  313  which is partially defined at this stage. Such a position is illustrated generally in  FIG. 3 . The armour wires may be supported on an outer rim surface of the body of the inner collar and an outer surface of the end fitting body. The wires may be secured in place using straps. The outer jacket  307  is then secured, using bolts  308 , to the waist of the end fitting body  301 . This forms the cavity  313 . 
     The outer seal ring  309  previously hooped on the flexible pipe body is now brought into position by sliding it in a direction illustrated by arrow B in  FIG. 3 , into the space formed between an inner surface of the jacket  307  and the outer sheath  108  of the flexible pipe body. The end ring  310  is then bolted to the jacket. As the ring is secured it is urged in a direction illustrated as direction B in  FIG. 3  towards the jacket. This urges the sealing ring  309  towards abutment surfaces on the jacket which activates the seal. 
     At this stage the end fitting is hung in a vertical direction. Epoxy or some other flowable sealant is then injected through injection ports (not shown) to fill the cavity  313  in the end fitting. This locks the wires further in place and helps improve overall mechanical integrity. 
     In conventional end fittings of flexible pipe the complete weight of the end fitting, prior to the filling of the cavity  313  with a material that secures the armour wires in place, is being borne by the anchoring of the seal ring  600  in to the underlying fluid barrier. This direct loading of the seal ring has the effect of increasing the probability that the end fitting process would induce movement at the seal ring and thereby impair its functionality. Where the inner collar is secured on the pipe the load would be shared between the action of the inner collar and the seal ring thereby reducing the risk associated with manipulating the end fitting prior to the filling of the cavity. 
     In one embodiment of the invention the inner collar  500  is secured by some mechanism (typically through the use of a long bolts  314 ) with sufficient force and proximity to the outer collar  700  such that the armour wire layers are clamped between the curved surface of the outer collar and the curved surface of the inner collar. This locks the wires in place. It will be appreciated that rather than each of the outer collar and inner collar being provided with a curved surface, only one of the collars may need such a support surface. Furthermore, it will be appreciated that the curve of the surface may be linear. 
     According to embodiments of the present invention, one or more of the support surfaces of the inner collar and/or outer collar may include grooves.  FIG. 9  illustrates the curved surface  506  and neck  502  of the inner collar  500  in more detail in accordance with an embodiment of the present invention. It is to be understood that only a section of the inner collar  500  is shown in  FIG. 9  for the sake of convenience. The collar can be an integral cylindrical structure or may be made in sections. Wires forming part of the inner tensile armour layer  106  are wound at a high lay angle with respect to the pipe body  100 . As each of these is bent away from the underlying barrier layer at around the bend region  708 , each wire is located in a respective guide slot  900 . The guide slot is preferably deep enough to encompass the whole diameter of the wire although it will be appreciated that the guide slots may be provided having less depth. Advantageously the guide slots  900  may have a depth of half a wire diameter with a further mating slot being provided on the curved surface  707  of the outer collar. 
     It will be appreciated that whilst the first armour layer is laid at a first angle with respect to the flexible pipe body, a further tensile armour layer is wound in a different direction. In such circumstances further guide slots (not shown) may be formed in the curved surface  506  of the inner collar at an angle to match the run off angle of those further wires. By providing grooved slots in at least one of the curved surfaces of the inner collar and/or outer collar the curved surfaces of the inner and outer collar can be brought into close juxtaposed relationship. This helps ensure that the neck  502  of the inner collar extends a maximum possible distance so as to support the barrier layer of the flexible pipe as much as possible. Effectively the neck  502  and outer collar neck and outer collar body will support the barrier layer between the end fitting body and a region of the flexible pipe body which retains its integrity. This also helps lock the wires in position to prevent movement which might otherwise damage the epoxy or other features of the end fitting. 
     Embodiments of the present invention thus provide an end fitting of a flexible pipe. The end fitting has an end fitting body having an open mouth which receives an end of a segment of flexible pipe body which is to be terminated in the end fitting. An inner collar is secured to the flexible pipe and this inner collar includes an elongate neck which has an inner surface which defines a substantially cylindrical bore. The diameter of this bore is selected to closely match the diameter of an outer surface of a barrier layer of the flexible pipe body. When the flexible pipe body is threaded through this central bore, the inner surface of the neck (and indeed a portion of the body) of the inner collar supports the barrier layer of the flexible pipe body. This helps prevent burst through of the material of the barrier layer caused by pressure of the transported fluid pushing through the barrier layer material at unsupported locations. 
     Embodiments of the present invention provide an inner collar which includes an end region having a curved outer surface. The curve of the outer surface is selected so as to determine a radius of curvature of wires of an armour layer of the flexible pipe when those wires are bent away from an axis of the flexible pipe during termination in an end fitting. Embodiments of the present invention also provide an outer collar member having a similar curved surface located on an inner surface region. 
     Embodiments of the present invention provide a method for securing wires of one or more armour layers of a flexible pipe when an end of flexible pipe body is terminated in an end fitting. The method includes bending the wires away from an axis of a flexible pipe and locating each wire individually (although more than one wire may be duly located) in a common groove. Contact surfaces of an inner collar and outer collar may be urged together to thereby lock the wires of the armour layer in position at predetermined locations. This helps prevent crumbling of epoxy used to fill the cavity which might otherwise occur when wires are not so locked in place due to a scissor-like action of the armour wires. 
     Embodiments of the present invention provide a method for securing an end fitting to a flexible pipe body. The method involves securing some rigid structure, for example, in the form of an inner and outer collar to an end of flexible pipe body. The end fitting is then secured to that structure, such as to an inner collar. By drawing the end fitting body towards the flexible pipe rather than drawing the flexible pipe body towards an end fitting, a more advantageous method of assembly can be provided. 
     Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of the words, for example “comprising” and “comprises”, means “including but not limited to”, and is not intended to (and does not) exclude other moieties, additives, components, integers or steps. 
     Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise. 
     Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith.