A mobile pipe welding machine includes a welding unit for welding pipes and a pipe receiver for guiding a pipe to the welding unit. The pipe receiver has a distal end facing away from the welding unit and a proximal end facing towards the welding unit. On the distal end there is at least one linearly movable contact body for lifting the pipe.

A device internally insulating a welded pipeline joint between pipes having an internal protective coating, in a first variant, includes a power actuator having a cylindrical elastic working member for radial expansion when excess pressure occurs inside its cavity. A cylindrical casing of elastic anti-adhesive material arranged coaxially on the member exterior can have channels for exhausting air and supplying a compound. In a second variant, the device sleevelessly insulates an annular space. A casing made of an anti-adhesive material is centrally reinforced by an elastic cord. Using a cylindrical elastic anti-adhesive casing coaxially arranged on the exterior of a power actuator elastic working member forms an annular space in the weld zone either using a protective sleeve, or by a reinforced casing portion. A vacuum in the space is filled by a compound. The elastic anti-adhesive material allows easy removal of the casing from the hardened compound surface.

A method of securing an insert in a preselected region of a workpiece. An opening wall is formed in the workpiece with an opening wall surface defining an opening to produce a remainder segment of the workpiece. The opening encompasses or coincides with the preselected region. An insert is provided to fit in the opening. An insert heated portion and a remainder segment heated portion are heated to a hot working temperature, at which they are plastically deformable. While the insert is subjected to an engagement motion, to move the insert relative to the remainder segment, an insert engagement surface of the insert is pressed against the opening wall surface, for plastic deformation of the insert heated portion and of the remainder segment heated portion, creating a metallic bond between the insert and the remainder segment. The insert and the remainder segment are allowed to cool, to bond them together.

A circumferential welded joint of a line pipe is formed by butting against each other end portions of steel pipes having a yield strength according to 5L Specification of API Standards not smaller than 555 N/mm.sup.2 and welding the butted portions in a circumferential direction. A joint strength ratio σ.sub.match=(TS-w/TS-b).Math.(YS-w/YS-b) represented by a product of a ratio between a tensile strength TS-w of a weld metal and a tensile strength TS-b of a base material and a ratio between a yield strength YS-w of the weld metal and a yield strength YS-b of the base material, and a critical equivalent plastic strain ε.sub.p-cri [%] for ductile crack generation in a base material heat affected zone satisfy Equation (1), and the yield strengths YS-w, YS-b of the weld metal and base material satisfy Equation (2).
σ.sub.match>4.85ε.sub.p-cri.sup.−0.31  (1)
YS-w/YS-b≧1.0  (2)

A tube assembly includes at least first and second tubes configured for coupling at respective ends. The first and second tubes each include a base material, and a weld interface at the respective end. The weld interface is proximate to an inner diameter and an outer diameter of the first and second tubes, and includes a weld interface segment extending therebetween. A work hardened weld assembly couples the base material of each of the first and second tubes. The work hardened weld assembly includes a weld fusion zone between the weld interfaces of the first and second tubes and the weld interface segments of the first and second tubes. The weld fusion zone is work hardened and at least the weld interface segments of the first and second tubes are work hardened between the work hardened weld fusion zone and the base material of the first and second tubes.

An internal heat exchanger (IHEX) for pipeline welding includes a drive system configured to move the IHEX into a position within at least one pipe section near a weld joint location with another pipe section. The IHEX further includes a cooling section including cooling structure configured to selectively cool one or more interior surface portions of the at least one pipe section, and a controller in communication with the cooling structure and configured to activate the cooling section when the IHEX is at the position within the at least one pipe section.

A method of sealing a hole in a wall of a hollow structure comprises providing a sealed chamber that is external to the structure and that is in fluid communication with an internal space of the structure via the hole. The structure may be a pipe-in-pipe structure and the internal space may be an annulus between outer and inner pipes. Fluid flows through the hole into or out of the chamber as the pressure and/or composition of fluid in the internal space is adjusted. Then, a plug is spun and friction-welded into the hole. The plug is inserted into the hole from within the chamber.

Method and device for centering and temporary fixation of tube parts (1, 5) in relation to each other's interior surfaces. A first tool (9) is centered relative to a tube part interior surface (2, 6) by a radially adjustable centering mechanism (13). The centering mechanism (13) is insertable in the tube part (1, 5). A second tool (10) is centered relative to the first tool (9), by a guiding mechanism (15) which cooperates for centering of the tools (9, 10) relative to one another. The second tool comprises fixing mechanism (17) to fix the exterior surface of the tube part (1, 5) to the second tool (10), and at least one third guide (18) which centers two such second tools (10) relative to one another in their mounted position on respective tube part end (4, 8) and at least one coupling member (19) to connect the two second tools (10).

A method of joining a first pipe section to a second pipe section includes positioning the two pipe sections in an end-to-end configuration to define therebetween a joint to be welded, measuring the degree of alignment of the pipe sections when they are in the end-to-end configuration in a position ready for welding, ascertaining the relative movement required of the pipe sections in order to improve their alignment, effecting the relative movement so ascertained, and welding together the two pipe sections. The method may include the use of geometric data of the end of the pipes in order to ascertain the relative movement required of the pipe sections. A control unit may be used to calculate, using such data, a target orientation that lines up the pipe sections. The measuring step may be performed using, for example, a laser or a camera and backlight.

A welding system includes a welding station having a weld station computer and a weld system in communication with the weld station computer. The weld system includes a supply of weld material, a welding device, and a weld supply motor assembly that moves the weld material to the welder device. The system further includes a weighting device operatively connected with the weld station computer to measure a weight of the supply of weld material and to communicate the weight of the supply of weld material to the weld station computer; and a sensor operatively connected with the weld supply motor assembly and the weld station computer so as to communicate the speed of the weld supply motor assembly to the weld station computer. The weld station computer is operatively connected to the weld supply motor assembly to control the speed of the motor assembly based on the weight data.