Pipeline internal centering device and associated method

1. A pipeline internal centering device for centering a first pipe relative to a second pipe, comprising:

(a) a centering unit for aligning the second pipe relative to the first pipe,

(b) a transport device for moving the pipeline internal centering device along a longitudinal axis of the pipeline internal centering device,

(c) a rotary device for rotating the pipeline internal centering device about its longitudinal axis, and

d) clamping elements which are moveable radially outwards by the centering unit to be braced against an interior surface of either the first pipe or the second pipe when the first pipe and second pipe are being aligned, and wherein the clamping elements are moveable radially inward to a neutral position in which one or more of the clamping elements are not braced against the interior of either the first pipe or the second pipe,

wherein the rotary device is configured to rotate the centering unit when the clamping elements are in the neutral position.

2. The pipeline internal centering device according to claim 1 , wherein the centering unit is moveable independently of the rotary device.

3. The pipeline internal centering device according to claim 1 , further comprising:

a base body,

wherein the rotary device is rigidly attached to the base body.

4. The pipeline internal centering device according to claim 1 , wherein the transport device comprises at least one transport roller

that has a rotational axis that runs transversely to the longitudinal axis, and

that is moveable radially inwards by a motor.

5. The pipeline internal centering device according to claim 1 , wherein the transport device has at least one transport roller arranged below a center of gravity of the pipeline internal centering device.

6. The pipeline internal centering device according to 1 , wherein the transport device has at least one transport roller which is moveable pneumatically and/or hydraulically in the radial direction.

7. The pipeline internal centering device according to claim 1 , wherein the rotary device comprises at least three transverse rollers, each of which has a rotational axis that extends along the longitudinal axis.

8. The pipeline internal centering device according to claim 7 , wherein

(a) the at least three transverse rollers are assembled such that they are radially immovable and collectively have an outer ring, and

(b) the transport device has at least one transport roller which is moveable by a motor

into a transport position in which the at least one transport roller at least partially protrudes above the outer ring, and

into a neutral position in which the at least one transport roller is arranged entirely within the outer ring.

9. The pipeline internal centering device according to claim 1 wherein the transport device has at least one transport roller located a distance from a front end—in the longitudinal direction of the pipeline internal centering device which is sufficient to permit the pipeline internal centering device to be rotated manually.

10. The pipeline internal centering device according to claim 8 , wherein a center of gravity of the pipeline internal centering device lies below a center point of the outer ring when in the operating position.

11. A method for producing a pipeline comprising the steps:

(i) centering of a first pipe relative to a second pipe by a pipeline internal centering device according to claim 1 ,

(ii) welding of the second pipe with the first pipe,

(iii) movement of the pipeline internal centering device along a longitudinal axis by the transport device,

(iv) activation of the rotary device,

(v) alignment of the pipeline internal centering device by rotating the pipeline internal centering device about the longitudinal axis, and

(vi) deactivation of the rotary device.

12. The method according to claim 11 , wherein rotation of the pipeline internal centering device during the alignment is conducted manually.

13. The pipeline internal centering device according to claim 1 , wherein the rotary device comprises at least four transverse rollers, each of which has a rotational axis that extends along the longitudinal axis.

14. The pipeline internal centering device according to claim 13 , wherein

(a) the at least four transverse rollers are assembled such that they are radially immovable and collectively have an outer ring, and

(b) the transport device has at least one transport roller which is moveable by a motor

into a transport position in which the at least one transport roller at least partially protrudes above the outer ring, and

into a neutral position in which the at least one transport roller is arranged entirely within the outer ring.

15. The pipeline internal centering device according to claim 14 , wherein a center of gravity of the pipeline internal centering device lies below a center point of the outer ring when in the operating position.