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 pipe-engaging 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 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 pipe-engaging 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.

Disclosed is a tube bending system for forming a hairpin tube, the tube bending system including: a supply of lubricant; a supply of atomizing medium; a bend mandrel, the bend mandrel comprising: a mandrel body and a mandrel head, the mandrel head being positionable within a length of a tube to be bent, the mandrel head including a downstream end with an orifice configured for injecting lubricant into the tube.

Disclosed is a tube bending system for forming a hairpin tube, the tube bending system including: a supply of lubricant; a supply of atomizing medium; a bend mandrel, the bend mandrel comprising: a mandrel body and a mandrel head, the mandrel head being positionable within a length of a tube to be bent, the mandrel head including a downstream end with an orifice configured for injecting lubricant into the tube.

The machine comprises a working apparatus arranged to carry out the working operation on a tube, or a similar blank, and a tube feeding device arranged to feed the tube towards the working apparatus. The working apparatus and the tube feeding device comprise respective clamping members for clamping the tube being worked. According to the invention, at least one of the clamping members of the working apparatus or of the tube feeding device is provided with a displacement sensor arranged to detect and measure any movements of the tube relative to said clamping member while the tube is clamped by said clamping member during the working operation.

The machine comprises a working apparatus arranged to carry out the working operation on a tube, or a similar blank, and a tube feeding device arranged to feed the tube towards the working apparatus. The working apparatus and the tube feeding device comprise respective clamping members for clamping the tube being worked. According to the invention, at least one of the clamping members of the working apparatus or of the tube feeding device is provided with a displacement sensor arranged to detect and measure any movements of the tube relative to said clamping member while the tube is clamped by said clamping member during the working operation.

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.

The purpose of the present invention is to provide a method for producing a pipe material and to provide a mandrel with which resistance between a member to be processed and the mandrel during bending processing can be reduced and overall processing time can be shortened. The method for producing a pipe material includes: a step for inserting a mandrel, which is provided on the inside thereof with a flow path through which dry ice powder flows and spray holes at the tip thereof for spraying the dry ice powder, inside pipe material; a step for spraying the dry ice powder from the spray holes inside the pipe material; and a step for performing bending processing on the pipe material wherein the mandrel has been inserted.

The purpose of the present invention is to provide a method for producing a pipe material and to provide a mandrel with which resistance between a member to be processed and the mandrel during bending processing can be reduced and overall processing time can be shortened. The method for producing a pipe material includes: a step for inserting a mandrel, which is provided on the inside thereof with a flow path through which dry ice powder flows and spray holes at the tip thereof for spraying the dry ice powder, inside pipe material; a step for spraying the dry ice powder from the spray holes inside the pipe material; and a step for performing bending processing on the pipe material wherein the mandrel has been inserted.

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.