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To the accuracy and reliability of actuating mechanisms of modern automatic machines for orbital (GTAW) welding of stationary butts of pipelines of NPP power units a number of specific requirements is specified. In particular, they concern the largest diameters of faceplates of welding heads of such automatic machines, in which, as a rule, all or the most of those mechanisms are located. This paper describes the designs of actuating mechanisms of modern automatic machines for GTAW of stationary butts of NPP pipelines, designed at the Scientific and engineering centre of welding and control in the field of nuclear energy. The mechanisms of clamping (fixation) of welding heads on the pipe being welded, the mechanism for stabilizing the arc length, the mechanism for rotation (rotator) of the faceplate around the axis of the pipes to be welded, the mechanism for automatic regulation of arc voltage, the mechanism for oscillation of non-consumable electrode (across the weld) and the mechanism of filler wire feed were developed. The results of industrial operation of some automatic machines for GTAW, designed at the Scientific and engineering centre of welding and control in the field of nuclear energy, are presented, in which the described mechanisms are used. The aim of this work is to present the results of works carried out at the Scientific and engineering centre of welding and control in the field of nuclear energy in the direction of creating components of automatic machines for GTAW of stationary butts of thin-walled pipelines of steels from austenitic, pearlite classes, carbon steels and alloys of non-ferrous metals (except aluminum and its alloys). [ABSTRACT FROM AUTHOR]

Electric drives are integral devices of any welding installations for arc and plasma welding. Since the accuracy and reliability of the actuating mechanisms in modern automatic machines for orbital welding of stationary joints of pipelines in NPP units present a number of specific requirements, these requirements are also imposed on the mechanisms for their driving, which required the development of the latter. The schemes of unified reversible DC drives of actuating mechanisms in modern automatic machines for orbital welding of stationary pipe joints in NPP are described. A transistor drive with feedback from an optical speed sensor, characterized by high reliability, ability to accurately pre-set (program) the rotation speed of the motor shaft, absence of mechanical switching contacts for starting or stopping, or for reversing, as well as a high-precision automatic arc voltage control device was designed. The results of industrial operation of some orbital welding machines, designed at the Scientific and engineering center of welding and control in the field of nuclear energy, are given, which use the described reversing drives and the device for automatic arc voltage control. The aim of this work is to present the results of the works carried out at the Scientific and engineering center of welding and control in the field of nuclear energy in the direction of creating components of automatic machines for orbital welding of stationary joints in thin-walled pipelines of austenitic, pearlitic and carbon steels and non-ferrous metal alloys (except aluminum and its alloys). 12 Ref., 8 Fig. [ABSTRACT FROM AUTHOR]

The carried out investigations and practice established that the quality of welded joints of pipelines, meeting the modern requirements largely depends on the quality of treatment of ends of groove edges of their butt joints prior to welding and on the quality of assembly of pipeline components directly before welding. The paper presents the results of experimental, technological and design works carried out at the Scientific and Engineering Center of Welding and Control in the Field of Nuclear Energy, on creating a facing tool for metal pipes of a diameter from 76 to 108 mm. It is shown that, in comparison with the best foreign analogues, the designed facing tool has a number of significant technological and operational advantages. [ABSTRACT FROM AUTHOR]

The article presents the results of development of technical means of semi-virtual type for training welders and welding production specialists at the SE Scientific and engineering center of welding and control in the field of nuclear energy in cooperation with the E.O. Paton Electric Welding Institute of the NAS of Ukraine and the G.E. Pukhov IPME of the NAS of Ukraine. The level of development of technical means for training and certification of welders and welding production specialists was considered, which allows predicting the expansion in the fields of application of modern information technologies, including those reproducing the mixed reality with the maximum adaptation of virtual space to real welding equipment and providing the remote access of telecommunication systems. It was shown that simplification of training and its approximation to the conditions of real welding processes is possible using a new generation of welding simulators, in which modern information technologies are widely applied. [ABSTRACT FROM AUTHOR]

The high-pressure heaters are the fundamentally necessary links of the second circuit power units of nuclear power plants with light water VVER-type reactors. They represent one-plane or two-plane piped spirals of carbon steel. The paper presents the results of selection and mastering the mechanized welding technology for applying high-pressure heaters in the manufacture and renovation repair. 20 Ref., 2 Fig. [ABSTRACT FROM AUTHOR]

Some theoretical problems of resistometric method for determination of welding arc spot coordinates and evaluation of speed of electrode movement during realization or simulation of arc welding, as well as the peculiarity of creating hardware part and software of simulating welding systems are considered using this method. The examples of using this method in the hardware-software complexes (welding simulators), as well as the basic variants of circuit design of devices for realization of resistometric method in the simulating welding systems, designed and industrially manufactured at the SE «Scientific and engineering center of welding and control in the field of nuclear energy of Ukraine of the E.O. Paton Electric Welding Institute of the NAS of Ukraine, are presented. 17 Ref., 4 Fig. [ABSTRACT FROM AUTHOR]