Joint, termination or cross-connection arrangement for a cable and method for providing a joint, termination or cross-connection arrangement

1. A joint, termination or cross-connection arrangement for a cable, comprising at least a first cable and a protective casing made of stainless steel,

the first cable including a metallic sheath made of copper or a copper-based alloy, and a first longitudinal end portion wherein the metallic sheath is exposed,

the protective casing being essentially rotationally symmetrical around a longitudinal axis (A) and including a first tubular end portion coaxial with the longitudinal axis (A) and through which the first longitudinal end portion of the first cable extends,

the arrangement characterised in further including a rotationally symmetrical transition sleeve coaxial with the longitudinal axis (A) of the protective casing, the transition sleeve including a first longitudinal end surface and a second longitudinal end surface,

wherein the transition sleeve, at the first longitudinal end surface thereof, is welded to the metallic sheath of the first cable around a whole circumference of the metallic sheath, and wherein the transition sleeve is further welded to the first tubular end portion of the protective casing around a whole circumference of the transition sleeve;

wherein the protective casing has a buffer coating that constitutes an outermost circumferential surface of the first tubular end portion welded to the transition sleeve, the buffer coating being made of nickel or a nickel-based alloy, and

wherein the transition sleeve is made of copper or a copper-based alloy, or is made of nickel or a nickel-based alloy.

2. The arrangement according to claim 1 , wherein the transition sleeve includes a first sleeve part extending from the first longitudinal end surface to the second longitudinal end surface of the transition sleeve, and an radially opposing second sleeve part extending from the first longitudinal end surface to the second longitudinal end surface of the transition sleeve.

3. The arrangement according to claim 1 , wherein the transition sleeve includes a first rotationally symmetrical section having a first inner diameter and a second rotationally symmetrical section having a second inner diameter greater than the first inner diameter, the second rotationally symmetrical section of the transition sleeve including the second longitudinal end surface of the transition sleeve, and

the transition sleeve is arranged such that the second rotationally symmetrical section thereof is at least partly provided radially outside of the first tubular end portion of the protective casing.

4. The arrangement according to claim 3 , wherein the second longitudinal end surface of the transition sleeve is welded to said buffer coating.

5. The arrangement according to claim 3 , wherein the transition sleeve is made of a same material as the metallic sheath of the first cable.

6. The arrangement according to claim 1 , wherein the transition sleeve is arranged such that it is partly interposed between an inner surface of the first tubular end portion of the protective casing and the metallic sheath of the first cable, and such that the transition sleeve extends longitudinally outside of the protective casing.

7. The arrangement according to claim 1 , wherein the metallic sheath of the first cable is a corrugated metallic sheath including peaks (p) and valleys (v), the peaks having a greater outer diameter than the valleys, and the first longitudinal end surface of the transition sleeve is welded to the metallic sheath of the first cable around the whole circumference of the metallic sheath at a peak (p) of the corrugated metallic sheath.

8. The arrangement according to claim 7 , wherein at least a longitudinal part of an inner surface of the transition sleeve has a corrugated form conforming to an outer surface of the corrugated metallic sheath of the first cable.

9. A method of providing a joint, termination or cross-connection arrangement for a cable, the arrangement including at least a first cable and a protective casing made of stainless steel, the first cable including a metallic sheath made of copper or a copper-based alloy, and a first longitudinal end portion wherein the metallic sheath is exposed, the protective casing being essentially rotationally symmetrical around a longitudinal axis (A) and including a first tubular end portion coaxial with the longitudinal axis (A), the method including the steps of:

a) introducing the first longitudinal end portion of the first cable into the first tubular end portion of the protective casing such that the first longitudinal end portion extends through the first tubular end portion,

b) arranging a rotationally symmetrical transition sleeve including a first longitudinal end surface and a second longitudinal end surface on the metallic sheath of the first cable such that when the first longitudinal end portion of the first cable extends through the first tubular end portion of the protective casing the transition sleeve is coaxial with the longitudinal axis (A) of the protective casing, the first longitudinal end surface is longitudinally distanced from the first tubular end portion, and the second longitudinal end surface is arranged radially inwards or radially outwards of the first tubular end portion,

c) welding the transition sleeve, at the first longitudinal end surface thereof, to the metallic sheath of the first cable around a whole circumference of the metallic sheath, and

d) either before or after step (c), welding the transition sleeve to the first tubular end portion of the protective casing around a whole circumference of the transition sleeve,

wherein any one of steps (b)-(d) may be performed either before or after step (a), but at least one of step (c) and (d) is performed after both step (a) and step (b),

wherein the protective casing has a buffer coating that constitutes an outermost circumferential surface of the first tubular end portion welded to the transition sleeve, the buffer coating being made of nickel or a nickel-based alloy, and

wherein the transition sleeve is made of copper or a copper-based alloy, or is made of nickel or a nickel-based alloy.

10. The method according to claim 9 , wherein step (b) includes providing a plurality of sleeve parts, assembling the sleeve parts so that the sleeve parts jointly define the rotationally symmetrical transition sleeve, and each sleeve part extends from the first longitudinal end surface to the second longitudinal end surface of the transition sleeve.

11. The method according to claim 9 , wherein the transition sleeve includes a first rotationally symmetrical section having a first inner diameter and a second rotationally symmetrical section having a second inner diameter greater than the first inner diameter, the second rotationally symmetrical section of the transition sleeve including the second longitudinal end surface of the transition sleeve, and wherein the transition sleeve is arranged on the metallic sheath of the first cable such that, when the first longitudinal end portion of the first cable extends through the first tubular end portion of the protective casing, the second rotationally symmetrical section of the transition sleeve is at least partly provided radially outside of the first tubular end portion of the protective casing such that the second longitudinal end surface of the transition sleeve is arranged radially outside of the first tubular end portion of the protective casing.

12. The method according to claim 11 , wherein welding the transitional sleeve to the first tubular end portion of the protective casing includes welding the second end surface of the transition sleeve to said buffer coating.

13. The method according to claim 11 , wherein the transition sleeve is made of a same material as the metallic sheath of the first cable.

14. The method according to claim 9 , wherein step (b) includes arranging the transition sleeve such that, when the first longitudinal end portion of the first cable extends through the first tubular end portion of the protective casing, the transition sleeve is partly interposed between an inner surface of the first tubular end portion of the protective casing and the metallic sheath of the first cable and the second longitudinal end surface of the transition sleeve is arranged radially inside of the first tubular end portion of the protective casing.

15. The method according to claim 9 , wherein the metallic sheath of the first cable is a corrugated metallic sheath including alternating peaks (p) and valleys (v), the peaks having a greater outer diameter than the valleys, and wherein the welding of the first longitudinal end surface of the transition sleeve to the metallic sheath is performed such that a resulting weld seam is located at a peak of the corrugated metallic sheath of the first cable around the whole circumference of the metallic sheath of the first cable.