The invention described herein generally pertains to locking mechanisms for levers operable to mount a tractor unit to a guide track and to engage a drive gear of the tractor unit to a track gear of the guide track. The levers for mounting the tractor unit and/or to engage the drive gear are lockable in a closed position. The closed position relates to a state of the levers when the tractor unit is mounted on the guide track or when the drive gear is engaged with the track gear. The levers can be easily operable to mount/dismount or engage/disengage, respectively.

Apparatus and method for welding steel boiler tubes in a space restricted area using a pulsed-arc welding process. The process includes the use of a consumable insert ring having a T-shaped profile and flux material to provide deep weld penetration by a GTAW welding machine. Notches in the consumable weld ring allow for visual inspection of tube fit prior to weld.

The invention discloses a method to determine the weld joint penetration from arc voltage measurements in gas tungsten arc welding (GTAW). It is based on an observation on the dynamic weld pool surface in GTAWthe surface tends to first expand toward the electrode and then be pushed away from the electrode after full penetration is established. For the pool surface in GTAW, localized partial keyholes around the arc axis as in plasma arc welding are not significant. The pool surface is relatively smooth. The arc voltage that reflects changes in the arc length thus first tends to reduce and then increases after full penetration is established. This invention thus tracks the arc voltage until the decrease slope becomes insignificant. Once full penetration is established, the current is reduced to decrease the weld penetration or first decrease the penetration growth for a certain period and then decrease the weld penetration.

A double-track welding system is provided. A first track is detachably mounted on a first side of a weld seam of a workpiece, and a second track is detachably mounted on a second side of the weld seam of the workpiece. The first track and the second track are both mounted on a fixed support, and the fixed support can drive the first track and second track to move. At least one welding trolley is arranged on each of the first track and the second track. An image acquisition component is used for acquiring an image of a part to be welded; a weld seam scanning device is used for acquiring the weld seam morphology; and a control system is used for controlling, according to the image of the part to be welded, the fixed support to move.

The invention described herein generally pertains to a system and method related to influencing a direction of an arc within a welding operation. Within a hot wire welding operation, an arc is generated between an electrode and a workpiece and a welding wire is energized while being supplied to a puddle formed by the electrode in order to deposit the liquefied welding wire onto the workpiece. A welder system and/or method is provided that controls a direction of the arc based on at least one of a polarity of the welding wire (via a power supply that energizes the welding wire), a location of the welding wire in proximity to the arc, a synchronization and/or de-synchronization of a polarity of the welding wire with the electrode, an activation and/or a de-activation of energizing of the welding wire, or a combination thereof.

A welding apparatus includes a housing having facing surfaces in the axial direction, and a welding head turning gear and first to third ring gears inside of the housing. A guide surface is formed on the facing surfaces. The welding head turning gear is coupled to a guide member, and the first to third ring gears are supported by the welding head turning gear and the guide member. Since a roller provided to the guide member rolls on the guide surface to rotatably support the first to third ring gears with respect to the housing, the welding apparatus can be lighter in weight and more compact compared to a conventional welding apparatus.

Properties and performance of weld material between metals in a weldment is controlled by modifying one or more of the nitrogen content and the carbon content to produce carbide (e.g. MC-type), nitride and/or complex carbide/nitride (e.g. MX-type) type precipitates. Fusion welding includes (i) adjusting shield gas composition to increase nitrogen/carbon gas and nitride/carbide species, (ii) adjusting composition of nitrogen/carbon in materials that participate in molten welding processes, (iii) direct addition of nitrides/carbides (e.g. powder form), controlled addition of nitride/carbide forming elements (e.g. Ti, Al), or addition of elements that increase/impede solubility of nitrogen/carbon or nitride/carbide promoting elements (e.g. Mn), and (iv) other processes, such as use of fluxes and additive materials. Weld materials have improved resistance to different cracking mechanisms (e.g., hot cracking mechanisms and solid state cracking mechanisms) and improved tensile related mechanical properties.

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.

An internal clamping and welding device for joining tubes by their distal ends, the device comprising movement means in order to be moved inside the tubes, separate clamping means for cooperating with the inner surfaces of the tubes to be welded, and a welding head mounted so as to be able to both rotate about a longitudinal axis of the tubes, and also pivot in order to be tiltable relative to a support of the clamping means.

An 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 pipe mount (21) and a welding electrode holder (22) for holding a welding electrode (23). An electric motor (31) is designed to drive the welding electrode holder (22) and thus turn it with respect to the pipe mount (21). The orbital welding head (20) has a chamber (50) for shielding gas. An optical oxygen sensor (40) is designed to measure an oxygen concentration in a measuring region (51) in the chamber (50). The oxygen sensor (40) is arranged outside the chamber (50) and is optically coupled to the measuring region (51) by an optical coupling.