A welding torch includes a head (3) having a body (11) bearing an electrode (13); an electric power source (27); and a filler metal wire (17) and a wire guide (19) guiding the filler metal wire (17) to the electrode (13). The body (11) is obtained by additive manufacturing from an electrically conductive metal, and the electrode (13) is electrically connected to the electric power source (27) by the metal constituting the body (11). The wire guide (19) includes an insulating sheath (29) inside which the filler metal wire (17) moves, and the filler metal wire (17) is electrically insulated from the potential of the body (11) by the insulating sheath (29).

A tube and tubesheet assembly is provided, which includes a tubesheet, the tubesheet comprising at least one tube insertion aperture therethrough; at least one tube inserted in the at least one tube insertion aperture; and a damage-resistant layer applied to an edge of the at least one tube and along an inner surface of a portion of the tube that is positioned within the corresponding tube insertion aperture. A heat exchanger including the assembly is also provided. A method is also provided for coupling a tube to a tubesheet. The method includes applying a damage-resistant layer to an edge of the tube and along an inner surface of a portion of the tube that is positioned within a tube insertion aperture in the tubesheet. The method can also be used to repair tubes and retrofit pre-existing tube-to-tubesheet joints.

A method for welding a steel pipe in a steel pipe structure and a joint is provided. The welding method includes: a measurement step of measuring a manufacturing error of the steel pipe, a calculation step of calculating the positions of the steel pipe and the joint where the manufacturing error measured in the measurement step is absorbed, and a welding step of welding the steel pipe and the joint at the positions of the steel pipe and the joint, the positions being calculated in the calculation step.

An orbital welder for welding together two pipes to be welded. The welder includes a fall brake for preventing a freefall of the welder. The welder includes a spatter shield for preventing dust from entering the outer housing and fowling sensitive machine components. The welder includes a torch assembly with manual adjustments. The welder includes an automatic lead/lag adjustment and control of that adjustment during a welding operation to automatically transition from a first weld zone to a second weld zone.

A system and method for determining weld travel speed. In one example, a welding system includes one or more sensors configured to provide a first indication correspond to a welding arc at a first time and to provide a second indication correspond to the welding arc at a second time. The welding system also includes processing circuitry configured to receive the first indication, to receive the second indication, and to determine a weld travel speed based on a weld length of the workpiece and a difference between the first and second times.

A robotic welding system comprises a supporting arm for attaching to a repositionable support structure, the supporting arm comprising a first mounting portion connectable to the repositionable support structure, and a second mounting portion rotatably coupled to the first mounting portion. A yaw rotary actuator rotates the second mounting portion about a yaw axis. A welding arm comprises a third mounting portion rotatably coupled to the second mounting portion of the supporting arm. A pitch rotary actuator rotates the third mounting portion about a pitch axis generally perpendicular to the yaw axis. A roll rotary actuator rotates a torch holder shaft about a roll axis generally perpendicular to the pitch axis. The shaft has a torch mounting portion for mounting a welding torch at an end thereof. A controller is operably coupled to the actuators to cause the welding torch to execute a welding pattern.

A method of controlling a back weld root surface includes arranging a sealing portion along the back weld root surface of a workpiece to form a purge region adjacent to a section of a joint, supplying a shielding gas within the purge region at a first flow rate, and applying a weld deposit across a front surface of the section of the joint. The shielding gas displaces an ambient environment within the purge region, and the back weld root surface of the weld deposit includes a positive root penetration relative to the back weld root surface based at least in part on the shielding gas within the purge region.

A rotor shaft for a turbine rotor of a turbine, in particular a steam turbine, having a shaft main body made of a first material and at least one ring which is made of a second material and is attached to the shaft main body, wherein the second material has equal or greater strength and/or greater corrosion resistance than the first material, wherein at least one blade slot is formed on the ring, and wherein the ring is materially bonded to the shaft main body by narrow-gap welding.

A rotor shaft for a turbine rotor of a turbine, in particular a steam turbine, having a shaft main body made of a first material and at least one ring which is made of a second material and is attached to the shaft main body, wherein the second material has equal or greater strength and/or greater corrosion resistance than the first material, wherein at least one blade slot is formed on the ring, and wherein the ring is materially bonded to the shaft main body by narrow-gap welding.

A method of manufacturing a fabricated object according to at least one embodiment includes a step of forming the fabricated object by laminating metal powder, the fabricated object including an opening portion that communicates with a hollow internal space, a step of mounting a plug in the opening portion, and a step of welding the plug mounted in the opening portion to the fabricated object.