GB2323144A - Protective sleeving - Google Patents

Abstract

A sleeving for an object, such as a cable, has a split which extends through the wall of the sleeving and continuously from a first end of the sleeving to a second end of the sleeving. The sleeving is biased towards the state in which the split is closed and resiliently deformable to allow reversible widening of the split, so that the object can be inserted into the sleeving.

Description

PROTECTIVE SLEEVING The present invention relates to sleeving particularly, but not exclusively, for the protection of offshore pipes, cables and the like.

The need for protection of offshore pipes and cables is well known: exposed pipe/cable is liable to be damaged both by abrasion and impact as a result of, for example, tidal activity. Various methods are currently used to provide protection, for example trenching, rockdumping and the use of concrete mattresses. These have the disadvantage of requiring a separate installation step from that of the pipe/cable, and therefore extra expense.

Broadly, the present invention provides sleeving, having a split which extends through its wall and which runs continuously between its ends, the sleeving being biased towards a state in which the split is closed, but resiliently deformable to allow reversible widening of the split.

In a second aspect, the invention provides a kit comprising lengths of sleeving according to the first aspect and means of securing the sleeving firmly in position around an object.

In a third aspect, the invention provides a method for protecting objects, the method employing sleeving according to the first aspect or a kit according to the second aspect.

To position the sleeving around an object to be protected, the split is widened and the object positioned within the sleeving. The split is then allowed to close, thereby enclosing the object. Using short lengths of sleeving, it may be possible to widen the whole length of the split simultaneously and locate the sleeving around the object in a single widening/closing step. However, it may be preferable to use longer lengths of sleeving, for which it is not conveniently possible to widen the entire extent of the split simultaneously. To use such sleeving, an initial portion of the split may be widened and the object partially located within the sleeve. An adjacent part of the split may then be widened, allowing more of the object to be enclosed. This may be repeated, to enclose the object along the entire length of the split.

The sleeving of this invention may find utility in a number of fields, for example in the above-mentioned protection of offshore pipes/cables, for mechanical protection of other objects and for thermally insulating objects (e.g. domestic water pipes).

The sleeving, being biased towards a state in which the split is closed, may grip an enclosed object of suitable size, i.e. comparable to, but larger than, the internal diameter of the sleeving in its natural state.

By this feature, sleeving of the present invention may hold itself in position around objects of suitable size.

It is envisioned that sleeving of various diameters may be provided for different uses, for example protecting pipes and cables of different thicknesses.

Being deformable, the sleeving is able to conform to variations (e.g. bends) in the object to be enclosed.

This is particularly advantageous in, for example, the protection of offshore cables, as the sleeving may be fitted before the cable is laid, despite the layout of the cable being different before and after laying.

In applications in which the sleeving is subjected to impacts or abrasion (e.g. protecting offshore pipes/cables), it is desirable to provide additional means for securing the sleeving firmly in position on the enclosed object. A number of suitable means are known in the art, for example, by gluing or by the use of cable ties or metal strapping. For certain applications (e.g.

thermally insulating pipes), the grip of the sleeve may be sufficient to hold it in place and additional means unnecessary.

The sleeving is preferably provided in straight, cylindrical lengths, one or more of which are used to surround lengths of pipe/cable. It is, however, contemplated that for other applications, the sleeving could be made with a non-circular (e.g. square) crosssection. It is further contemplated that sleeving could be provided in a "T"- or "X"-shaped layout, e.g. for protecting junctions. The split in such pieces would need to run continuously between all (e.g. 3 or 4) ends of the sleeving. For convenience, the following description will refer to straight, cylindrical lengths of sleeving, though the invention is not limited in this respect.

The split in a piece of sleeving may in principle be of any form, as long as it extends through the wall and runs continuously between the ends. The split is, however, preferably helical. Once one part (preferably one end) of a piece of helically split sleeving has been positioned around the object, it is possible to position the rest of the length by winding the free end around the object; it is not necessary to widen the split directly.

It may be desirable to provide sleeving split in other ways, however. For example, if it is not feasible to wind the sleeving around the object, sleeving having a straight split may be used, to be fitted from one side of the object.

Where more than one length of sleeving is used on a particular object, it is desirable that the ends of adjacent pieces of sleeving co-operate, to prevent the object from being exposed between the lengths. For this reason, lengths of sleeving may be provided with ends that interlock or which may overlap. The join may then be secured in the region of interlock/overlap, e.g. using metal strapping or a cable tie. Such interlocking may be achieved by providing a step in the end wall of the sleeve which mates with a corresponding but opposite step in the adjacent sleeve. Other forms of interlocking include one or more projections on the end of one of the sleeves which are received in corresponding recesses in the other sleeve. Interlocking may also be achieved by eg. matching corrugations or undulations in the ends of adjacent sleeves. For use at the ends of the object to be enclosed, sleeving may be provided with only one interlockable end, the other end being flush or otherwise shaped as appropriate.

The material of the sleeving may be chosen according to the intended application. For protection against damage from impact and/or abrasion, the material is suitably a natural rubber or synthetic elastomer. Such materials meet the requirement of being deformable and have a high impact resistance. Additionally, they may be highly elastic, allowing the sleeve to grip the object strongly and (in conjunction with the surface of the object) may possess a high coefficient of friction; both these features helping the sleeving to remain in position. Alternative or additional materials may be used, however, as long as the requirement of resilient deformation is met: for example a reflective coating may be provided to provide thermal insulation.

The use of EPDM elastomers (ethylene-propylene polymers) allows the sleeving to be produced by an extrusion process and is thus particularly preferable.

EPDM is especially suitable for offshore applications, having been proven in marine environments, e.g. in fenders.

It will be recognised that, when used alone or in conjunction with appropriate securing means, the sleeving of this invention is conveniently removable from the enclosed object. This feature allows sections of (e.g.

damaged) sleeving to be replaced, without e.g. excavating the object and without removing sleeving from the entire extent of the object.

An embodiment of the invention will now be described in greater detail by way of example, with reference to the enclosed drawings, in which: Fig. 1 shows a length of sleeving being fitted around a pipe; Fig. 2 shows a length of sleeving of Fig. 1 at a later stage in the fitting of that sleeve to the pipe; and Fig. 3 shows two interlocked lengths of sleeving on a pipe, secured with cable ties.

The length of sleeving 2 shown in Figs. 1 and 2 comprises a cylindrical tube of extruded EPDM elastomer material, having two open ends 4, 6. Half of the cylinder is absent for a short distance from each end, leaving a half-cylindrical protrusion 8, 10 at each end.

A split 12 extends through the wall of the sleeve and runs in a continuous helix from the base 14 of one protrusion to the base 16 of the other. The sleeve is therefore split along its entire length.

In the natural state of the sleeve, the split is closed. The sleeve may be deformed to widen the split, allowing an object to be placed within the sleeve, without the need to insert it via an end. Being made of a resilient material, the sleeve is biased to return to the natural state, partially or wholly enclosing the object. In the figures, the object is a pipe 18 of diameter similar to, but slightly larger than, the natural internal diameter of the sleeve. On returning to its natural state after insertion of the pipe, the sleeve is therefore able to grip the pipe and hold itself in position thereon.

In Fig. 1, a short region 20 at one end of the sleeve 2 has been deformed to widen the split and the pipe 18 has been introduced. To enclose the pipe along the entire length of the sleeve, the deformed portion is first released, causing the enclosed region of pipe to be gripped by the sleeve. The free end 22 of the sleeve is then wound round the pipe, causing the split to be widened, the pipe to be introduced and the split to be closed progressively along the remaining length of the sleeve. The arrows in Fig. 1 show the direction of winding required, the solid arrow being in front of the pipe, the dashed arrow behind. Fig. 2 shows the sleeve during this process, after approximately 1 turns round the pipe.

In this embodiment, the split is a left-handed helix (i.e. in the shape of a left-handed screw thread). The free end is therefore wound round the pipe clockwise, as seen from the free end 22 towards the gripping end 24.

The converse would obviously apply for a right-handed helix.

Fig. 3 shows an arrangement in which there are two lengths of sleeving on a pipe 18. One length 30 is of the kind as shown in Figs. 1 and 2 (a "middle-type" length). The other length 32 is of a kind particularly suitable for the ends of pipes, having only one protrusion (an "end-type" length). The other end is flush with a plane perpendicular to the long axis of the sleeve. The two lengths are shown in an interlocked position, i.e. the single protrusion of the "end-type" length is engaged with one of the protrusions of the "middle-type" length. Together, the two engaging protrusions form a cylinder, allowing the pipe to be covered without gaps in the region of interlock. A third length may be positioned adjacent to the "middle-type" length, and so on to cover the whole length of the pipe.

As shown in Fig. 3, this embodiment has cable ties 34, 36, which have been positioned at intervals along the lengths of sleeving and which have been tightened around the circumference of the sleeving. The use of additional securing means is optional, to hold the sleeving in position with greater security. If such means are used, it is desirable at least to secure each interlocking region, as these are the regions least securely fixed by the sleeving alone. The cable tie 34 performs this function in this embodiment.

Claims (12)

CLAIMS:

1. A sleeving for an object, the sleeving having a split which extends through the wall of the sleeving and continuously from a first end of the sleeving to a second end of the sleeving, the sleeving being biased towards the state in which the split is closed and resiliently deformable to allow reversible widening of the split.

2. A sleeving according to claim 1 which is elongate, the split extending helically along the sleeving.

3. A sleeving according to claim 1 which has more than two ends and is shaped to receive an object including a junction, the split extending continuously to the more than two ends of the sleeving.

4. A sleeving according to claim 1, claim 2 or claim 3 which is flexible, whereby an object located within the sleeving is permitted to flex.

5. A sleeving according to any proceeding claim including at one or both ends means for connecting the sleeving to a second sleeving longitudinally displaced along the object from the sleeving.

6. A sleeving according to claim 5 wherein said means for connecting the sleeving to a second sleeving comprise at said one or each end of the sleeving a protrusion projecting from the or each end of the sleeving and shaped to receive a portion of the side surface of an object encircled by the sleeving, whereby the protrusion co-operates with the protrusion extending from the second sleeving to surround a section of the object.

7. A kit comprising a plurality of sleevings according to any proceeding claim and means of securing the sleevings around an object.

8. A method of protecting a section of an object, comprising: deforming a sleeving having a split which extends through the wall of the sleeving and continuously from a first end of the sleeving to a second end of the sleeving, the sleeving being biased towards a state in which the split is closed, said deformation widening the split; inserting the object into the sleeving through the split; and allowing the split to close.

9. A method according to claim 8 further comprising a step of securing the sleeving to the object.

10. A method according to claim 8 or claim 9 in which the sleeving is elongate, and said steps of deforming the sleeving to widen the split, inserting the object into the sleeving through the split, and allowing the split to close are performed progressively along the length of the sleeving.

11. A method according to claim 10 in which the split extends helically from one end of the sleeving to another and the steps of deforming the sleeving to widen the split, inserting the object into the sleeving, and allowing the split to close are performed by winding the sleeving progressively along the object.

12. A method of protecting an object substantially as herein described with reference to the attached figures.

12. A method according to any of claims 8-12 in which a plurality of sleevings are attached around the object at respective locations there along.

13. A method according to claim 12 further comprising a step of connecting said plurality of sleevings to each other.

14. A sleeving substantially as herein described with reference to the attached figures.

15. A method of protecting an object substantially as herein described with reference to the attached figures.

CLAIMS: 1. A sleeving for an object, the sleeving having a split which extends through the wall of the sleeving and in a continuous helix from a first end of the sleeving to a second end of the sleeving, the sleeving being biased towards the state in which the split is closed and resiliently deformable to allow reversible widening of the split.

2. A sleeving according to claim 1 which has more than two ends and is shaped to receive an object including a junction, the split extending continuously to the more than two ends of the sleeving.

3. A sleeving according to claim 1 or claim 2 which is flexible, whereby an object located within the sleeving is permitted to flex.

4. A sleeving according to any of the preceding claims including at one or both ends means for connecting the sleeving to a second sleeving longitudinally displaced along the object from the sleeving.

5. A sleeving according to claim 4 wherein said means for connecting the sleeving to a second sleeving comprise at said one or each end of the sleeving a protrusion projecting from the or each end of the sleeving and shaped to receive a portion of the side surface of an object encircled by the sleeving, whereby the protrusion co-operates with the protrusion extending from the second sleeving to surround a section of the object.

6. A kit comprising a plurality of sleevings according to any of the preceding claims and means of securing the sleevings around an object.

7. A method of protecting a section of an object, comprising: deforming a sleeving having a split which extends helically along the wall of the sleeving and continuously from a first end of the sleeving to a second end of the sleeving, the sleeving being biased towards a state in which the split is closed, said deformation widening the split; inserting the object into the sleeving through the split; and allowing the split to close by winding the sleeving progressively along the object.

8. A method according to claim 7 further comprising a step of securing the sleeving to the object.

9. A method according to claims 7 or 8 in which a plurality of sleevings are attached around the object at respective locations therealong.

10. A method according to claim 9 further comprising a step of connecting said plurality of sleevings to each other.

11. A sleeving substantially as herein described with reference to the attached figures.