A welding backing insert (20) includes a body (22), a retention member (24) and an insertion member (26). The retention member (24) includes at least one leg (28) being deflectable to enable insertion into a hollow profile structural extrusions (14). At least one leg (28) tries to return to its original position exerting a force on the hollow profile structural extrusion (14) to retain the backing insert (20) in the hollow profile structural extrusion (14). The insertion member (26) projects from the body for inserting into a second hollow profile structural extrusion (14). A gap-control joint spacer (50) projects from the body to provide a gap between adjacent hollow profile structural extrusions.

Provided are a gas-shielded arc welding method, a welded joint, and a method for producing the welded joint. In gas-shielded arc welding including one-side butt welding of steel plates in the present invention, a ceramic-made backing material is attached to a bottom surface of a groove, and root pass is performed in one pass using a welding current I of 200 to 450 A and a welding voltage V of 25 to 50 V while a welding heat input Q is controlled within the range defined by formula 1 below. 0.4? G?1 ?Q ?0.6? G+1 (formula 1)
Here, G in formula 1 is a root gap (mm).

Provided are a gas-shielded arc welding method, a welded joint, and a method for producing the welded joint. In gas-shielded arc welding including one-side butt welding of steel plates in the present invention, a ceramic-made backing material is attached to a bottom surface of a groove, and root pass is performed in one pass using a welding current I of 200 to 450 A and a welding voltage V of 25 to 50 V while a welding heat input Q is controlled within the range defined by formula 1 below. 0.4? G?1 ?Q ?0.6? G+1 (formula 1)
Here, G in formula 1 is a root gap (mm).

A weld kit is presented for use in creating a weld with limited access to a structure. The weld kit contains a back plate being a combination of a thermic material attached to a metallic material. Additionally, the weld kit has a lowering device secured to the back plate. A plurality of tacking nodes travel through both the thermic material and the metallic material of the back plate. The plurality of tacking nodes are operative to accept and distribute heat from a welding arc to create a tack weld at a location where at least one of the plurality of tacking nodes contacts a weld joint. The presented weld kit may be used to repair a damaged enclosed structure. Additionally, the presented weld kit may also be used to create an enclosed structure in a manufacture type environment.

Method for producing a component system having a first component with a first component portion and a second component with a second component portion, including the following steps: connecting, in particular welding or soldering, the first component portion, which consists of an aluminum alloy, to the second component portion, which in particular consists of a naturally aged aluminum alloy, a copper alloy or an iron alloy, in particular a steel alloy, so as to form a connection seam; artificially aging the connection seam such that the yield strength of the connection seam is above the yield strength of the first component portion and/or of the second component portion; and deforming, in particular deep-drawing and/or stretch-drawing, the component system.

Method for producing a component system having a first component with a first component portion and a second component with a second component portion, including the following steps: connecting, in particular welding or soldering, the first component portion, which consists of an aluminum alloy, to the second component portion, which in particular consists of a naturally aged aluminum alloy, a copper alloy or an iron alloy, in particular a steel alloy, so as to form a connection seam; artificially aging the connection seam such that the yield strength of the connection seam is above the yield strength of the first component portion and/or of the second component portion; and deforming, in particular deep-drawing and/or stretch-drawing, the component system.

A pressure vessel includes: (a) a cylindrical sidewall having a wall thickness, an inside surface, an outside surface, and the cylindrical sidewall extending between a first end and a second end, wherein one of the first end or the second end includes a sidewall edge that forms part of an outwardly opening weld groove; (b) an end cap constructed to engage the cylindrical sidewall edge, the end cap comprising an end cap edge corresponding to the sidewall edge and that, when combined with the sidewall edge, forms the outwardly opening weld groove; (c) a cylindrically extending backer bar located in support of the outwardly opening weld groove formed by the sidewall edge and the end cap edge; and (d) a weld joint formed in the outwardly opening weld groove and holding the cylindrical sidewall to the end cap. A method for welding a pressure vessel sidewall and end cap together is provided.

A water-soluble insert for use in joining pipes, made of a material comprising a salt selected from the group consisting of KCl, Na Cl, and mixtures thereof; and MgO. Upon addition of a small amount of water to the material, the MgO reacts with hygroscopic impurities in the chloride salt to provide a material with superior properties. The insert is cast from the material, in general by being placed on a form and compressed. Also disclosed is the use of the insert in joining the ends of two pipes, especially pipes made from thermoplastic. The insert is placed in the matching pipe ends, which are then welded. After the join is complete, water is flowed through the pipe, dissolving the insert.

A water-soluble insert for use in joining pipes, made of a material comprising a salt selected from the group consisting of KCl, Na Cl, and mixtures thereof; and MgO. Upon addition of a small amount of water to the material, the MgO reacts with hygroscopic impurities in the chloride salt to provide a material with superior properties. The insert is cast from the material, in general by being placed on a form and compressed. Also disclosed is the use of the insert in joining the ends of two pipes, especially pipes made from thermoplastic. The insert is placed in the matching pipe ends, which are then welded. After the join is complete, water is flowed through the pipe, dissolving the insert.

A method for limiting fitting distortion when welding a fitting to an in-service pipelinewhere the fitting includes a thick, longitudinally extending, seam located between fitting halvesinvolves welding, on each side of the fitting, a middle third section of the seam in a pyramid-like fashion using an inward progression starting from an end of the middle third section along a profile of a seam bevel, and welding outer third sections of the seam using an outward progression from an end adjacent to the middle third section along a profile of the seam bevel. The welding of each of the three sections per side includes a temper bead welding technique of at least two layers to provide stress relief in lieu of traditional post weld heat treatment.