One aspect of the present disclosure is a manufacturing device by which the bent pipe is obtained by bending a double pipe. The device includes inner and intermediate core metals, a bending mold, and a controller. The controller executes: a first bending process in which first and second pipes are bent by the bending mold in a first direction in a first area of the double pipe where the inner and intermediate core metals are placed; a second bending process in which the first and second pipes are bent, after the first bending process, by the bending mold in a second direction in a second area of the double pipe where the inner and intermediate core metals are placed; and a first bending-back process in which the second pipe is bent, after the first bending process, in a direction opposite to the first direction in the first area.

A forming apparatus that forms a metal pipe material includes an electrode that holds the metal pipe material and supplies electric power to the metal pipe material to heat the metal pipe material, a forming die that quenches and forms the expanded metal pipe, and a member that suppresses quenching, in which a region where quenching is not performed in the metal pipe is adjusted by adjusting a length of the member.

A forming apparatus that forms a metal pipe material includes an electrode that holds the metal pipe material and supplies electric power to the metal pipe material to heat the metal pipe material, a forming die that quenches and forms the expanded metal pipe, and a member that suppresses quenching, in which a region where quenching is not performed in the metal pipe is adjusted by adjusting a length of the member.

A variable-diameter full-support mandrel structure with a slider-type cross section for preventing a reverse rotation of a ratchet wheel includes a movable mandrel segment and a straight shank, and the movable mandrel segment and the straight shank are connected through a quick-disconnect universal joint. A rotating shaft of the movable mandrel segment is provided with a connecting rod mounting flange, a ratchet wheel, a reverse ratchet wheel, a bearing, and a limit clamp ring in sequence. An outer ring of the bearing is provided with a pawl mounting frame. The connecting rod mounting flange and the pawl mounting frame are respectively hinged to a long connecting rod and a short connecting rod, and the long connecting rod and the short connecting rod are hinged to slider components in an outer ring. The slider component has a Z-shaped structure composed of two layers of arc blocks.

A method for manufacturing a pipe is described, wherein the method comprises a step of fastening a second mechanical quick connection member to a rectilinear hollow tubular body, a step of positioning the rectilinear hollow tubular body in a bending machine so that the angular coding mechanism of the second mechanical quick connection member is in a reference angular position with respect to said bending machine, and a step of bending the rectilinear hollow tubular body as a function of said angular reference position.

A method for manufacturing a pipe is described, wherein the method comprises a step of fastening a second mechanical quick connection member to a rectilinear hollow tubular body, a step of positioning the rectilinear hollow tubular body in a bending machine so that the angular coding mechanism of the second mechanical quick connection member is in a reference angular position with respect to said bending machine, and a step of bending the rectilinear hollow tubular body as a function of said angular reference position.

Method for mitigating stress corrosion cracking at an internal (i.e., wetted-side) weld area in piping of a nuclear power plant includes the steps of actuating a radially movable tool to produce a radial bad against the internal (i.e., normally wetted) surfaces at or near the weld area to create a deep residual compressive stress state at the wetted surface of the weld. The method permits post-process verification by physical measurements of surface distortion.

Method for mitigating stress corrosion cracking at an internal (i.e., wetted-side) weld area in piping of a nuclear power plant includes the steps of actuating a radially movable tool to produce a radial bad against the internal (i.e., normally wetted) surfaces at or near the weld area to create a deep residual compressive stress state at the wetted surface of the weld. The method permits post-process verification by physical measurements of surface distortion.

The invention relates to a device for bending pipes, in particular coated pipes, in a preferred manner insulated pipes and/or pipes that are coated with PU foam/PUR rigid foam, for pipelines, said device having a basic body which can be positioned in the pipe and on which a running gear unit is provided for movement in the pipe and having at least three contact elements for producing a contact with an inside wall of the pipe for introducing a bending force, wherein at least two contact elements are provided on one side of the basic body on the ends of the basic body, and at least one contact element is arranged on the opposite side of the basic body, and wherein at least one of the contact elements is provided so as to be movable in relation to the basic body in the direction of the inside wall of the pipe by means of a force-introducing element. In addition the invention relates to a method for bending such pipes.

The invention relates to a device for bending pipes, in particular coated pipes, in a preferred manner insulated pipes and/or pipes that are coated with PU foam/PUR rigid foam, for pipelines, said device having a basic body which can be positioned in the pipe and on which a running gear unit is provided for movement in the pipe and having at least three contact elements for producing a contact with an inside wall of the pipe for introducing a bending force, wherein at least two contact elements are provided on one side of the basic body on the ends of the basic body, and at least one contact element is arranged on the opposite side of the basic body, and wherein at least one of the contact elements is provided so as to be movable in relation to the basic body in the direction of the inside wall of the pipe by means of a force-introducing element. In addition the invention relates to a method for bending such pipes.