A method and apparatus for bending a pipe to mitigate internal wrinkling, with particular benefit when bending a lined pipe upon spooling. Bending is performed continuously by advancing the pipe through a bending zone while an internal mandrel is held at the bending zone to resist wrinkling. In one variant, the mandrel comprises longitudinally-spaced pipeengaging elements and a tensile link between the elements allows relative movement between the elements. A holdback connection on one of the elements applies hold-back force to that element to be transmitted to the other element via the tensile link. In another variant, the mandrel comprises an elongate pipe-engaging body with a hold-back connection at one end of the body. The body is flexible to bend with the pipe and is shaped to engage an inner surface of the pipe along most of the length of the body.

A method and an apparatus bend a pipe to mitigate internal wrinkling, with particular benefit when bending a lined pipe upon spooling. Bending is performed continuously by advancing the pipe through a bending zone while an internal mandrel is held at the bending zone to resist wrinkling. In one variant, the mandrel includes longitudinally-spaced pipe-engaging elements and a tensile link between the elements allows relative movement between the elements. A hold-back connection on one of the elements applies hold-back force to that element to be transmitted to the other element via the tensile link. In another variant, the mandrel includes an elongate pipe-engaging body with a hold-back connection at one end of the body. The body is flexible to bend with the pipe and is shaped to engage an inner surface of the pipe along most of the length of the body.

A method and an apparatus bend a pipe to mitigate internal wrinkling, with particular benefit when bending a lined pipe upon spooling. Bending is performed continuously by advancing the pipe through a bending zone while an internal mandrel is held at the bending zone to resist wrinkling. In one variant, the mandrel includes longitudinally-spaced pipe-engaging elements and a tensile link between the elements allows relative movement between the elements. A hold-back connection on one of the elements applies hold-back force to that element to be transmitted to the other element via the tensile link. In another variant, the mandrel includes an elongate pipe-engaging body with a hold-back connection at one end of the body. The body is flexible to bend with the pipe and is shaped to engage an inner surface of the pipe along most of the length of the body.

The invention relates to a device for the internal bending of pipes (100), in particular of coated pipes, for pipelines with a base body (11) which can be positioned in the pipe and which has on at least one side (12), preferably the underside, at least one support surface (13) with an inner wall (101) of a pipe (100) to be bent, wherein the base body (11) has a support surface (13) opposite, preferably the upper side, on which at least one tool for introducing a bending force into the pipe (100) is movably provided, wherein the tool is movable relative to the base body (11) via at least one actuator (18, 20) for introducing the bending force. The invention provides that the tool is provided as a tool element (21) which has at least two bending force introduction sections (28, 29) for introducing the bending force into the pipe (100), which are each movable relative to the base body (11) by at least one actuator (18, 20).

The invention relates to a device for the internal bending of pipes (100), in particular of coated pipes, for pipelines with a base body (11) which can be positioned in the pipe and which has on at least one side (12), preferably the underside, at least one support surface (13) with an inner wall (101) of a pipe (100) to be bent, wherein the base body (11) has a support surface (13) opposite, preferably the upper side, on which at least one tool for introducing a bending force into the pipe (100) is movably provided, wherein the tool is movable relative to the base body (11) via at least one actuator (18, 20) for introducing the bending force. The invention provides that the tool is provided as a tool element (21) which has at least two bending force introduction sections (28, 29) for introducing the bending force into the pipe (100), which are each movable relative to the base body (11) by at least one actuator (18, 20).

A clamp member and a counter pressure member are hingedly connected together about a rotary axis, and a fitting portion of a fitting protrusion that is positioned in a fitting recess is located at a foreside in an advancing direction of the pipe relative to a position where a bending operation of the pipe is initiated, and a mating portion at which a first groove part of the clamp member and a second groove part of a counter pressure member mate is located at a backside in the advancing direction of the pipe relative to the position where the bending operation of the pipe is initiated. The counter pressure member comprises a first member supported rotatably about the rotary axis, a second member detachably connected to the first member, and a third member detachably connected to the second member, which are connected together by a common connecting member (e.g., bolt).

A clamp member and a counter pressure member are hingedly connected together about a rotary axis, and a fitting portion of a fitting protrusion that is positioned in a fitting recess is located at a foreside in an advancing direction of the pipe relative to a position where a bending operation of the pipe is initiated, and a mating portion at which a first groove part of the clamp member and a second groove part of a counter pressure member mate is located at a backside in the advancing direction of the pipe relative to the position where the bending operation of the pipe is initiated. The counter pressure member comprises a first member supported rotatably about the rotary axis, a second member detachably connected to the first member, and a third member detachably connected to the second member, which are connected together by a common connecting member (e.g., bolt).

An apparatus for improving the quality of tube bending; adapted to be used in bending machines and comprises a substantially longitudinally extended mandrel, adapted to be inserted into a tube to be bent and having a rigid portion and a flexible portion arranged in series, the latter comprising a series of mandrel segments connected by articulated joints; the apparatus also comprises at least one motion-sensitive sensor, which is integral with at least one of the mandrel segments, and elements for processing the motion information acquired by the sensor.

An apparatus for improving the quality of tube bending; adapted to be used in bending machines and comprises a substantially longitudinally extended mandrel, adapted to be inserted into a tube to be bent and having a rigid portion and a flexible portion arranged in series, the latter comprising a series of mandrel segments connected by articulated joints; the apparatus also comprises at least one motion-sensitive sensor, which is integral with at least one of the mandrel segments, and elements for processing the motion information acquired by the sensor.

A galling-resistive insert is positioned on an outer surface of a mandrel assembly. The insert is secured at the outer surface of the mandrel assembly and functions to reduce galling of an inner surface of a tubular blank during a rotary-draw bending operation.