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[en] This paper describes a remote controlled dual arm manipulator system cutting a still pipe at high place. Remotely cutting work is one of the tasks with complicated working conditions. An overview and comparison of cutting techniques for piping is given. These include a plasma arc, arc saw, linear-shaped explosive charge, and 'conventional cutting methods' for metal cutting. The dual arm manipulators consist of two LBR iiwa 14 R820's. LBR iiwa is a light weight 7 DOF articulated manipulator that weighs 29.5 kg with a payload capacity of 14 kg, and is able to move precisely with +/-0.1 mm repeatability. It assembles parts delicately and detects external forces using integrated torque sensors
[en] Materials used for steam piping of power plants are exposed to high temperatures and high pressures over long periods of time. As a consequence, forged Grade 91 alloy steel is commonly chosen to meet these demands. However, complicated structures such as a valve body are often machined from large forged blocks resulting in long machining time and the material weight being heavy. Therefore, by manufacturing a valve body with near net technology, both the time and material weight can be reduced. This paper will present 1) a survey of the dimensions of a valve body HIPed to a near net shape, 2) an investigation of the mechanical properties of Grade 91 powder, 3) a comparison of the structure of a HIPed product and a forged product, 4) The machining time and material weight of a near net shaped (NNS) product by HIP compared to a forged product. This paper will illustrate that the NNS product was able to reduce the machining time by 30% and the material weight by 40% less than when machining from a forged product.
[en] Due to the high degree of required dimensional accuracy in its manufacturing, repairing of lining pipes with flanges requires a long installation period. With the conventional method, we have to wait more than three weeks to start lining installation after the start of onsite construction, because pipe dimensions are determined onsite then lining installation is conducted at shop. It causes prolongation of the onsite installation period. Therefore, we have tried to improve the dimensional accuracy in its manufacturing by applying three-dimensional as-built laser measurement device which enables high precision measurement. In addition, we established a new process from manufacturing to installation. As a result, we achieved successful shortening of onsite lining pipe repairing period. However, there are still some conditions and points to be dealt with to apply this method to the actual construction. We organize them and provide important points in this paper. (author)
[en] In order to develop heavy gauge WPHY-80 pipe fitting steel with high strength and low temperature toughness, the experimental research and manufacturing technology have been studied in this paper. The continuous cooling phase transformation behavior of the material under deforming condition was investigated. The microstructure of the steel at different cooling rates was observed by microscope. The temperature gradient rolling process in rough rolling stage was developed, which prompt the deformation penetrated from the surface to the center. It could refine the grain size in the center of the thick plate to enhance uniformity of the microstructure along the thickness direction. By utilizing this process route, the heavy gauge (54mm) WPHY-80 pipe fitting steel with excellent mechanical properties was developed in Shougang steel (SG). The WPHY-80 plates obtained high strength and stable low temperature impact toughness. (paper)
[en] The research alliance SAVE aims to provide new calculation methods for avoiding gas entrainment into pump intakes and also new design recommendations. Frequently hollow surface vortices at pump intakes are the cause for gas entrainment into pumps. Since gas entrainment may lead to performance losses and even complete failure of the pump it has to be avoided in general. The investigations of the SAVE project were focused on the formation of surface vortices, measures to avoid them as well as the effects of gas entrainment on centrifugal pumps and fittings. The work packages included in the subproject C concerned the development of numerical and analytical methods to determine the occurrence and shape of surface vortices. Based upon this, new recommendations for the calculation of the necessary submergence, the performing of experiments at model scale and vortex breaking measures were developed. As a summary of the subproject C of the research alliance SAVE it may be pointed out that by improving one-phase and twophase numerical approaches it was possible to reproduce the gas entraining vortices, which were observed in the experiments of the SAVE project, with good accuracy. That includes in particular operational states at a critical water level, at which the air core of the vortex reaches the pump suction nozzle. Apart from that, two analytical correlations for the calculation of the critical submergence were developed based on the experimental and simulation data. Some insights were gained from the experiments concerning the vortex breaking and vortex reducing measures as well as for performing experiments at small scales.
[en] Fatigue design of Class-l piping of NPP is carried out using Section-III of American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel code. The fatigue design criteria of ASME are based on the concept of safety factor, which does not provide means for the management of uncertainties for consistently reliable and economical designs. In this regards, a work is taken up to estimate the implicit reliability level associated with fatigue design criteria of Class-l piping specified by ASME Section III, NB-3650. As ASME fatigue curve is not in the form of analytical expression, the reliability level of pipeline fittings and joints is evaluated using the mean fatigue curve developed by Argonne National Laboratory (ANL). The methodology employed for reliability evaluation is FORM, HORSM and MCS. The limit state function for fatigue damage is found to be sensitive to eight parameters, which are systematically modelled as stochastic variables during reliability estimation. In conclusion a number of important aspects related to reliability of various piping product and joints are discussed. A computational example illustrates the developed procedure for a typical pipeline. (author)
[en] The work describes the equipment of the company, that must be tested and certified: installations (facilities) for thermal, mechanical and thermal-hydraulic testing and research, implemented in the nominal, transient and emergency modes of NPP operations. The characteristics of this equipment are also given
[ru]В работе описано оборудование компании, которое должно быть подвергнуто испытанию и сертификации: установки (стенды) для проведения тепломеханических и тепло-гидравлических испытаний и исследований, реализующихся в номинальных, переходных и аварийных режимах работы АЭС. Даны характеристики этого оборудования
[en] Modern operation of nuclear power plants dictate to modular penetrations the implementation of several requirements simultaneously, such as, for example, sealing, fire protection and explosion protection of equipment. Roxtec products help to combine the solution of all these issues in a single penetration
[ru]Современные условия эксплуатации АЭС диктуют выполнение модульными проходками одновременно сразу нескольких требований, таких как, например, герметизация, огнезащита и взрывозащита оборудования. Продукция Roxtec позволяет совместить решение всех этих вопросов в единой проходке
[en] This study aims to develop a technology that allows the reuse of the end fittings by non-destructive detachment of the rolled joint between the end fitting and the pressure tube. Therefore, this technique would provide the detachment and removal of the pressure tube from the end fitting faster, reducing the reactor shutdown time, and eliminates the need of transport, storage and production of new fittings. The system works on the principle of inductive heating, in which the rolled joint area is rapidly heated up to T3 [°C] followed by a quick axial load applied in order to detach the end fitting from the rolled joint. Certain information about the rolled joint main features was analyzed in order to determine the characteristics of the equipment such as the axial load required for the detachment considering different conditions. The paper is dedicated to specialists working in research and technological engineering. (authors)