A welding device which performs butt welding of tubes includes a table. The table supports a rotary member of a circular-arc shape to which a welding torch is mounted, and a gear train that rotates the rotary member around a center axis of the tubes. The welding device includes a first movement mechanism that moves the table in a first direction perpendicular to the center axis of the tubes, and a second movement mechanism that moves the first movement mechanism in a second direction perpendicular to the center axis of the tubes and the first direction.

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.

An orbital welding device (1) for welding two pieces of pipe, the orbital welding device (1) having a welding current source (10) in a welding current source housing (11) and an orbital welding head (20), which is separate from the welding current source housing (11) and is connected to the welding current source (10) by a cable (2), the orbital welding head (20) having a chamber (50) for the use of shielding gas (50) and/or the orbital welding device (1) having a purging device (90) for the use of shielding gas, preferably back-up shielding gas or purge gas, the orbital welding device (1) having an oxygen sensor (40), wherein the oxygen sensor (40) is arranged in or on the welding current source housing (11).

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 holding portion having a torch mount at an end thereof configured for mounting a welding torch about a roll axis generally perpendicular to the pitch axis. A controller is operably coupled to the actuators to cause the welding torch to execute a welding pattern.

An orbital welding device (1), having a welding current source (10) in a welding current source housing (11) and a base controller (12), and an orbital welding head (20) connected to the welding current source (10) by a cable (2), the orbital welding head (20) having a pipe mount (21) and a welding electrode holder (22) mounted rotatably with respect to the pipe mount (21) for holding a welding electrode (23). A motor (31) is designed to drive the welding electrode holder (22). The orbital welding head (20) has a chamber (50) for shielding gas, and an electrical circuit (60) that is connected: to a position sensor (41) designed to generate a position value (41.1); and/or to a memory device (61) designed to store one or more loading values (61.1) and/or one or more calibrating values (61.2) in the memory device (61).

A mechanized welding system and associated methods are disclosed. The system includes a welding torch and a two-axis motion apparatus operatively connected to the welding torch and configured to move the welding torch in two independent axes of motion (e.g., X and Y) during an orbital welding procedure to produce at least one of a fillet weld or a groove weld on a workpiece. The system also includes a motion controller operatively connected to the two-axis motion apparatus. The motion controller is configured to control movement of the two-axis motion apparatus along the two axes of motion in a coordinated manner to continuously and simultaneously adjust the welding torch in a height direction and an oscillation direction with respect to the workpiece, while accounting for a physical work angle of the welding torch with respect to the workpiece, and without the two-axis motion apparatus having to be tilted with respect to the workpiece when the physical work angle is changed.

Disclosed example orbital welding devices include a welding current source in a welding current source housing and a base controller, and an orbital welding head connected to the welding current source by a cable, the orbital welding head having a pipe mount and a welding electrode holder mounted rotatably with respect to the pipe mount for holding a welding electrode. A motor is designed to drive the welding electrode holder. The orbital welding head has a chamber for shielding gas, and an electrical circuit that is connected: to a position sensor designed to generate a position value; and/or to a memory device designed to store one or more loading values and/or one or more calibrating values in the memory device.

Disclosed example orbital welding heads or an orbital welding apparatus for welding of tubes, wherein a light source is arranged in a welding chamber, being positioned diametrically opposed to the observation window. This arrangement of the light source of the observation window allows for a very reliable, precise alignment of end portions of tubes to be welded. According to a further aspect, a control device is provided for controlling the light source located in the welding chamber, so that different light signals can be emitted with the light source. According to a third aspect, the observation window is formed by a glass pane, wherein the glass pane has a darkening coating typical of welding glasses, wherein at least one front-facing section of the glass pane is exposed, which is configured so as to be not darkening or less darkening, thus allowing light to freely exit from this edge portion.

The invention provides a method for coaxially welding together two tubes. Axial ends of the tube walls of the respective tubes are machined in such a way that they have a stepped shape over at least a first part of the tube wall thicknesses. The stepped shapes complement each other. The method comprises the subsequent steps of A positioning the first tube and the second tube coaxially with respect to each other, wherein the machined axial ends contact each other at least over the first part of the first tube wall thickness and the first part of the second tube wall thickness and wherein the first stepped shape of the machined axial end of the first tube wall and the second stepped shape of the machined axial end of the second tube wall fit into each other, and wherein a seam is present between the first parts of the first tube and the second tube thicknesses, B fixating the first tube and the second tube at discrete positions over the circumference of the seam via attachment welds, C welding the first tube and the second tube to each other over the entire circumference of the first tube and the second tube, wherein the circumferential weld extends over the entire thickness of the first tube all and over the entire thickness of the second tube wall.

A robotic crawler for back purging a weld location in a piping circuit includes a body, one or more conveyors coupled to the body for transporting the robotic crawler within the piping circuit, first and second seal assemblies configured to generate an interference seal with an interior of the piping circuit, a pair of extendable arms, each extendable arm supporting a respective one of the first and second seal assemblies on an opposite side of the body, each respective extendable arm selectively extendable and retractable with respect to the body to adjust a position of the respective seal assembly with respect to the body, and an inert gas flow valve for providing an inert gas into a sealed area defined between the first and second seal assemblies.