Abstract: A method and device for manufacturing thin-walled hollow bodies comprising concentric layers employs, for thin-walled structural parts of chemical installations subjected to stress at high temperatures, non-layered pipes of single-metal materials. Due to the methods of manufacture, structural parts of these materials have disadvantages because the single materials of which they are built cannot simultaneously satisfy the demands of corrosion resistance, high-temperature stability and resistance to scaling. According to the new method, for example, thin-walled pipes of concentric, non-corrosive, high-temperature stable, and non-scaling material layers are intended to be produced. For the non-corrosive inner layer, for example, a conventional thin-walled pipe is used.

Abstract: A method for manufacturing thin-walled hollow bodies comprising concentric layers forming thin-walled structural parts of chemical installations subjected to stress at high temperatures, thereby replacing non-layered pipes of single-metal materials. Due to the methods of manufacture, structural parts of these single-metal materials have disadvantages because the single materials of which they are built cannot simultaneously satisfy the demands of corrosion resistance, high-temperature stability and resistance of scaling. According to the new method, for example, thin-walled pipes of concentric, non-corrosive, high-temperature stable, and non-scaling material layers are intended to be produced. For the non-corrosive inner layer, for example, a conventional thin-walled pipe is used.

Abstract: In a method of preparing from weld material a component having a curvature which is symmetrical in rotation, difficulties arise, more particularly in the case of large and heavy components, in guiding the treatment zone. The treatment zone remains in a horizontal positio for welding, on stationary welding heads. For economic form welding under numerical control, it is proposed that the rotational axis of the component be tilted stepwise, to an extent depending upon the advance of the buildup of weld material layers, around a horizontal axis perpendicular to the rotational axis, the welding heads being adjusted stepwise as the tilt position varies.

Abstract: A method of manufacturing a tube bend of a metal comprises positioning a base ring in the range of the welding device, using the welding device to deposit a first section of metal on the ring, moving the ring and the welding device through an arc relatively to each other by substantially the thickness of the first section of metal and thereafter depositing a subsequent section over the first section and repeating the moving and the depositing until the desired section thickness is formed into a wall. The device includes means for mounting a plate for pivotal movement and a base ring mounted on the plate for movement therewith below a welding device arranged so that the welding device and the plate remove relatively through an arcuate path so that a series of sections of metal may be built up into a tube bend wall. The welding device advantageously includes an electrode feeder and the apparatus preferably includes a welding device to provide a plating along the side of the wall section which is built up.