Disclosed is a method for producing a cylindrical membrane wall including a plurality of tubes having a coolant passing through an inner part thereof. The method includes producing a plurality of sub-bundles by welding a plurality of tubes to each other after longitudinally arranging the tubes to be adjacent to each other in parallel, producing a plurality of panel-type bundles by welding the sub-bundles to each other, forming a plurality of curved bundles having a curved surface of a predetermined curvature by pressing the panel-type bundles, and welding the curved bundles to each other using a jig.

A water-degradable welding purge dam apparatus for purging a weld zone of a pipe assembly having first and second pipes having respective first and second pipe ends to be welded together at a root gap. The purge dam apparatus includes a blocking plate assembly having an outer blocking plate, an inner blocking plate, and zero or more interior blocking plates. The blocking plate assembly may be formed from one or more water degradable materials to facilitate removal of the purge dam apparatus from the pipe assembly using an aqueous fluid following welding. At least one of the blocking plates may include a plurality of fluid flow apertures to aid distribution of the aqueous fluid through the blocking plate assembly. If desired, first and second ones of the blocking plate assembly may be ganged together by an interconnection assembly to form a ganged set of blocking plate assemblies.

A mobile hardbanding system that uses PTA welding to perform hardbanding on drill string sections at the well site. The inventive system allows alternate use of PTA and MIG welding. Both a PTA torch and a MIG torch are provided. Changing from one type of welding to the other is simplified by including separate electrical, gas, and cooling conduits for each torch. The torch not in use is parked in the welding compartment near the weld box. The powder hopper for the PTA welding assembly may be mounted on a swivel arm so that it can be moved out of the way when the MIG torch is in use.

A welding process, welding system and welded article are disclosed. The welding process includes generating a first beam from a stationary fusion apparatus and generating a second beam from a rotatable fusion apparatus. The first beam and the second beam form a weld in an article. The welding system includes a stationary fusion apparatus and a rotatable fusion apparatus directed at an article to be welded, the stationary fusion apparatus and rotatable fusion apparatus being arranged and disposed to form a single weld in the article. The welded article includes a first element welded to a second element, the welded article having a decreased root reinforcement, in an inaccessible region, from that of a hybrid stationary fusion apparatus.

A mobile hardbanding system that uses PTA welding to perform hardbanding on drill string sections at the well site. The inventive system allows alternate use of PTA and MIG welding. Both a PTA torch and a MIG torch are provided. Changing from one type of welding to the other is simplified by including separate electrical, gas, and cooling conduits for each torch. The torch not in use is parked in the welding compartment near the weld box. The powder hopper for the PTA welding assembly may be mounted on a swivel arm so that it can be moved out of the way when the MIG torch is in use.

A turntable assembly for performing welding or other operations in a pivotably-mounted J-lay tower is disclosed. The assembly includes an annular turntable supported by a base frame to turn about a pipe string in use and a tilt-compensating mechanism acting on the base frame to level the turntable as the tower pivots in use. The tilt-compensating mechanism includes at least one support that is driveable up and down with respect to the tower. In the embodiment disclosed, the support is a carriage movable along an upright track that pivots with the tower.

The invention describes methods of welding onto laminated devices using a low temperature welding process. Also described are laminated devices with welds that do not disrupt a brazed core block of sheets in the laminated devices. Novel laminated devices with welded features for servicing the devices are also described.

The invention describes methods of welding onto laminated devices using a low temperature welding process. Also described are laminated devices with welds that do not disrupt a brazed core block of sheets in the laminated devices. Novel laminated devices with welded features for servicing the devices are also described.

A system for manufacturing boiler tubes includes a first spindle for receiving a first tube having a first weld preparation, a second spindle for receiving a second tube having a second weld preparation, the first spindle and the second spindle being rotatable synchronously, and a welding device having a first weld head. The welding device is configured to automatically weld the first tube to the second tube according to a control routine stored in memory to produce a boiler tube.

A water-degradable welding purge dam apparatus for purging a weld zone of a pipe assembly having first and second pipes having respective first and second pipe ends to be welded together at a root gap. The purge dam apparatus includes a blocking plate assembly having an outer blocking plate, an inner blocking plate, and zero or more interior blocking plates. The blocking plate assembly may be formed from one or more water degradable materials to facilitate removal of the purge dam apparatus from the pipe assembly using an aqueous fluid following welding. At least one of the blocking plates may include a plurality of fluid flow apertures to aid distribution of the aqueous fluid through the blocking plate assembly. If desired, first and second ones of the blocking plate assembly may be ganged together by an interconnection assembly to form a ganged set of blocking plate assemblies.