Abstract: Novel compositions of matter are disclosed; perfluoro-1,1-di(orthoxylyl) methane, perfluoro-1,1-di(orthoxylyl) ethane and perfluoro-1,1-di(orthoxylyl) propane. The compositions are made by cobalt trifluoride fluorination of 1,1-di(orthoxylyl) methane, 1,1-di(orthoxylyl) ethane and 1,1-di(orthoxylyl) propane. The compositions have utility as vapor phase soldering fluids.

Abstract: A device is provided for clamping and centering two parts to be welded together, such as a flange or edge against a pipe or two pipes against each other, or a pipe against a pipe, so that the parts can be welded together in a clamped position. The device comprises a clamping tool which is in the form of a portable, manually operable unit. The tool preferably has clamping tongs with interchangeable clamping pins for interior clamping.

Abstract: A method of cladding a nonaluminum core with at least one aluminum cladding strip by preheating both the core rod and the strip with the former being preheated to about 1000.degree. F. to 1300.degree. F. and the latter being heated to about 600.degree. F. to 1000.degree. F. Cleaning the core rod and the strip and passing them through a controlled environment chamber containing a reducing or neutral gas. Lubricating the bonding roll grooves to provide a substantially continuous coating of lubricant thereon. Galling of the aluminum strip or strips to the bonding rolls is resisted as a result of this process.

Abstract: A method for joining thin-walled tubular parts (1, 2) of metal by forge/diffusion welding comprising establishing a joint (3) between opposed bounding surfaces (4, 5), the joint having increasing height from one side (7) to the other. During heating of the parts the joint (3) is supplied with an inert or reducing flushing gas, for instance hydrogen, until the oxides are removed from the joint surfaces (4, 5). By subsequently pressing the parts together, complete forge/diffusion welding is obtained. It is also suggested to reduce the cross-section of the parts excentrically in the joint area and press the parts out to their initial cross-section during the forge/diffusion welding. A packer (8) is used to close the joint (3) on the side where the distance between the parts (1, 2) is the greatest. Means (10, 11) are shown for performing the welding under water.

Abstract: Failure of an electronic component (18) during soldering of leads (16--16) thereof to a substrate (12) can be reduced by directing a gas such as air across the top surface (13) of the substrate against the leads. The gas directed against the leads serves to drive off corrosive flux vapors which would otherwise migrate upwardly along the leads causing corrosion thereto and failure of the component.

Abstract: Tubular members which are to be joined by establishing a circumferential weld bead at abutting ends thereof are engaged by an internal clamp which defines a circumferential groove aligned with the weld zone. This circumferential groove, which is formed by cooperating surface grooves in a plurality of radially movable jaws, is filled with an inert gas during welding. The action of the jaws insures centering of the tubular members and prevents shrinkage and other misalignment during welding.

Abstract: A TIG pipe welding method which employs two sets of machine guide surfaces on the pipe ends. First radially inner guide surfaces cooperate with a sensor coupled to the welding torch to continuously monitor the arc gap between the welding electrode and the weld puddle as the welding electrode moves around the circumference of the pipe. The second set of radially outer surfaces cooperate with a welding carriage to guide the carriage and welding modules around the pipe joint. The carriage is constructed to provide a sealed welding chamber surrounding the electrode. An additional flow of shielding gas is provided around the torch electrode of a TIG or hot wire TIG welding module to augment the normal gas shield.