Patent ID: 11859748
Assignee: NIPPON STEEL CORPORATION
Field: Machine tools (Mechanical engineering)
Classification: CPC B  F  G | IPC B  F

Claim 3:
4. A method for producing coiled tubing with joints in which the coiled tubing is composed of a long pipe wound around a reel, the joints being connected to both end portions of the pipe, respectively, by using a production facility,
wherein:
the production facility comprises:
a conveyance system which conveys a pipe in a longitudinal direction,
a welding apparatus which is disposed along the conveyance system and which performs girth welding that welds together end portions of a plurality of pipes conveyed by the conveyance system to form a long pipe,
a winding apparatus which is disposed along the conveyance system and which winds the long pipe that is conveyed by the conveyance system around a reel, and
an X-ray inspection apparatus which is disposed between the welding apparatus and the winding apparatus along the conveyance system and which inspects a girth weld zone of the long pipe;
the conveyance system comprises pinch rollers that pinch and guide the long pipe, at a position that is furthest on a downstream side in a conveyance direction of the long pipe; and
the production method comprises:
a first joint girth welding step of girth welding a first joint to a front end portion of the pipe that is initially conveyed, by means of the welding apparatus,
a first girth weld zone inspection step of inspecting a girth weld zone of the first joint by means of the X-ray inspection apparatus,
a long pipe formation step of forming the long pipe by repeating steps of performing girth welding to weld together end portions of pipes that follow the pipe to which the first joint is girth welded by means of the welding apparatus, and further inspecting girth weld zones of the end portions by means of the X-ray inspection apparatus,
a second joint girth welding step of girth welding a second joint to a rear end portion of the long pipe by means of the welding apparatus,
a second girth weld zone inspection step of inspecting a girth weld zone of the second joint by means of the X-ray inspection apparatus,
an attachment attaching step of attaching an attachment to a rear end portion of the second joint,
an attachment girth welding step of girth welding a front end portion of a different pipe to a rear end portion of the attachment by means of the welding apparatus,
a cutting step of, in a state in which the second joint is located in a vicinity of the winding apparatus, fixing the rear end portion of the long pipe to which the second joint is girth welded to the winding apparatus, and thereafter cutting a region of the different pipe located between the winding apparatus and the pinch rollers; and
an attachment detaching step of detaching the attachment from the second joint.