The Experts below are selected from a list of 1098 Experts worldwide ranked by ideXlab platform
Gregory Zysk - One of the best experts on this subject based on the ideXlab platform.
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Steam Plant Piping Vibration Study and Resolution
Volume 4: Fluid-Structure Interaction, 2007Co-Authors: Gregory Zysk, John GiamarinoAbstract:The world’s largest district steam co-generation plant was successfully brought on line following major modifications in the spring of 2005. During the initial “shake-down” operation of the high pressure steam send-out system, Piping Vibrations were experienced, which disrupted flow meters and other equipment. Operation of one of five identical flow control valves, used in parallel to regulate steam flow to the street distribution system, resulted in the high Vibration levels. To investigate the cause of the Vibrations, a project was undertaken, which included testing of the Piping system utilizing dynamic pressure transducers and accelerometers and engineering analysis of the acoustics and Piping structural dynamics. Multiple combinations of open and closed valves were investigated, and the likely root cause was identified as flow-induced Vibration originating at a tee in the system. A Piping layout modification was designed. The modification consisted of rerouting the Piping downstream of one flow control valve to bypass the source of the flow-induced Vibration. Following the Piping modification, further tests were conducted that showed the reconfiguration successfully mitigated the Vibration.Copyright © 2007 by ASME
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Farley Main Steam Flow-Induced Vibration Investigation
Thermal Hydraulic Problems Sloshing Phenomena and Extreme Loads on Structures, 2002Co-Authors: Gregory Zysk, Michael OliverAbstract:Piping Vibration had been observed in the Farley Unit 2 main steam system since plant start-up. Hanger damage occurred in several portions of the system, including inside containment, in the Main Steam Valve Room (MSVR), and in the turbine building. A program was undertaken to determine the cause of the failures in the main steam supports. This program included the installation of diagnostic equipment, data analysis, and acoustic and structural modeling in an effort to determine the root cause of the Piping Vibration. The program also addressed a modified system support scheme, which included the addition of Vibration absorbing and dampening devices. Recommendations were also provided to resolve the Vibration issue.Copyright © 2002 by ASME
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Acoustic and Structural Modeling of Farley Main Steam Flow-Induced Vibration
Thermal Hydraulic Problems Sloshing Phenomena and Extreme Loads on Structures, 2002Co-Authors: Gregory ZyskAbstract:Piping Vibration has been observed in the Farley Unit 2 main steam system since plant start-up. Dynamic pressure and accelerometer data obtained during operation indicated that this was flow induced Vibration. Acoustic modeling was utilized to evaluate potential origination locations of the pressure oscillation in the main steam system. Forcing pressure oscillations or “exciters” over a broad range of frequencies were imposed at various locations to simulate turbulent sources within the system. The relative magnitude of the acoustic response at the measured locations was compared to the data and used as a basis for determining the location of the source oscillation. The acoustic model was also used to generate forcing functions for a Piping structural model that was used to evaluate measured accelerometer data.Copyright © 2002 by ASME
Akira Maekawa - One of the best experts on this subject based on the ideXlab platform.
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EXPERIMENTAL AND NUMERICAL STUDY ON PRESSURE PULSATIONS UNDER VARIOUS ACOUSTIC BOUNDARY CONDITIONS IN Piping SYSTEMS.
Journal of Pressure Vessel Technology, 2017Co-Authors: Akira Maekawa, Michiyasu Noda, Takashi Tsuji, Tsuneo A. Takahashi, Minoru Kato, Katsuhisa FujitaAbstract:To improve design and troubleshooting techniques of Piping systems for operating power plants, it is necessary to investigate, by experiment and simulation, the behavior of fluid inside the Piping system in detail. This study was conducted using full-scale Piping system under conditions that could seriously threaten the plant operation, by matching pressure pulsations, acoustic resonance, and Piping natural frequency. Although Piping Vibration is reported to influence fluid pressure pulsations, there were no such examples of influence in this experiment. Knowing that the opening ratio of the pressure control valve affects the boundary condition for acoustic resonance, experiment and simulation at different opening ratios were conducted. It has been suggested that the cases in which a valve partially open at 25% or less should not be taken as a closed end. This finding conflicts with such a widespread design assumption.
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Experimental study on a noncontact method using laser displacement sensors to measure Vibration stress in Piping systems
Measurement, 2016Co-Authors: Akira Maekawa, Michiyasu Noda, Masanori ShintaniAbstract:Abstract This study presents a noncontact measurement method of Vibration induced stress (Vibration stress) using multiple laser displacement sensors and clarifies its applicability to Piping Vibration. In the beam structures such as Piping, the stress due to bending deformation can be caused by Vibration. In the presented method, the Vibration displacement in the beam structures induced by the bending deformation is measured at three different locations using laser displacement sensors in a noncontact manner and the Vibration stress is estimated by a simple calculation based on the beam theory. First, an applicability validation of the presented method was done by a Vibration test using a cantilevered beam plate. This validation was done by comparing measurements by the presented method and the conventional method using strain gauges. Next, an experimental validation was conducted by the Vibration test using a pipe specimen, and the applicability to the Piping Vibration was confirmed.
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development of noncontact measurement methods using multiple laser displacement sensors for bending and torsional Vibration stresses in Piping systems
International Journal of Pressure Vessels and Piping, 2016Co-Authors: Akira Maekawa, Michiyasu Noda, Masanori Shintani, Michiaki SuzukiAbstract:Abstract In this study, two methods to measure bending and torsional Vibration stresses of Piping systems conveniently and quickly are proposed. The proposed methods are composed of a modeling approach of Piping Vibration and noncontact measurement techniques. The methods assume the Vibration modes as a primary mode within the measuring range without the mode-identification and then estimate the Vibration stress by approximating the Vibration displacements measured in a noncontact manner as a primary mode. This paper presents the principles and calculation formulas of both methods and shows the measurement techniques for the bending and torsional Vibration stresses using laser displacement sensors. Finally the applicability of one method is discussed based on the results of a Vibration experiment.
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Experiment and Simulation on Pressure Pulsation Accompanied by Acoustic Resonance and Piping Vibration
Volume 4: Fluid-Structure Interaction, 2011Co-Authors: Takashi Tsuji, Akira Maekawa, Michiyasu Noda, Tsuneo A. Takahashi, Minoru Kato, Katsuhisa FujitaAbstract:To improve condition-based maintenance (CBM) techniques for operating plants, it is necessary to investigate, by experiments and numerical simulations, on the behavior of fluid inside Piping system in detail. This study was conducted using the full-scale Piping system under conditions that could seriously threaten the plant operation, by matching pressure pulsation, acoustic resonance and Piping natural frequency. Although Piping Vibration is reported to influence fluid pressure pulsation, there were few examples of such influence in the conditions of this experiment. Knowing that the opening ratio of the pressure control valve affects the boundary condition for acoustic resonance, the experiment and numerical simulation at different opening ratios were conducted. It was suggested that there are cases in which a valve partially open at 25% or less shouldn’t be taken as a closed end. This finding conflicts with widespread design assumption.Copyright © 2011 by ASME
Michiyasu Noda - One of the best experts on this subject based on the ideXlab platform.
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EXPERIMENTAL AND NUMERICAL STUDY ON PRESSURE PULSATIONS UNDER VARIOUS ACOUSTIC BOUNDARY CONDITIONS IN Piping SYSTEMS.
Journal of Pressure Vessel Technology, 2017Co-Authors: Akira Maekawa, Michiyasu Noda, Takashi Tsuji, Tsuneo A. Takahashi, Minoru Kato, Katsuhisa FujitaAbstract:To improve design and troubleshooting techniques of Piping systems for operating power plants, it is necessary to investigate, by experiment and simulation, the behavior of fluid inside the Piping system in detail. This study was conducted using full-scale Piping system under conditions that could seriously threaten the plant operation, by matching pressure pulsations, acoustic resonance, and Piping natural frequency. Although Piping Vibration is reported to influence fluid pressure pulsations, there were no such examples of influence in this experiment. Knowing that the opening ratio of the pressure control valve affects the boundary condition for acoustic resonance, experiment and simulation at different opening ratios were conducted. It has been suggested that the cases in which a valve partially open at 25% or less should not be taken as a closed end. This finding conflicts with such a widespread design assumption.
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Experimental study on a noncontact method using laser displacement sensors to measure Vibration stress in Piping systems
Measurement, 2016Co-Authors: Akira Maekawa, Michiyasu Noda, Masanori ShintaniAbstract:Abstract This study presents a noncontact measurement method of Vibration induced stress (Vibration stress) using multiple laser displacement sensors and clarifies its applicability to Piping Vibration. In the beam structures such as Piping, the stress due to bending deformation can be caused by Vibration. In the presented method, the Vibration displacement in the beam structures induced by the bending deformation is measured at three different locations using laser displacement sensors in a noncontact manner and the Vibration stress is estimated by a simple calculation based on the beam theory. First, an applicability validation of the presented method was done by a Vibration test using a cantilevered beam plate. This validation was done by comparing measurements by the presented method and the conventional method using strain gauges. Next, an experimental validation was conducted by the Vibration test using a pipe specimen, and the applicability to the Piping Vibration was confirmed.
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development of noncontact measurement methods using multiple laser displacement sensors for bending and torsional Vibration stresses in Piping systems
International Journal of Pressure Vessels and Piping, 2016Co-Authors: Akira Maekawa, Michiyasu Noda, Masanori Shintani, Michiaki SuzukiAbstract:Abstract In this study, two methods to measure bending and torsional Vibration stresses of Piping systems conveniently and quickly are proposed. The proposed methods are composed of a modeling approach of Piping Vibration and noncontact measurement techniques. The methods assume the Vibration modes as a primary mode within the measuring range without the mode-identification and then estimate the Vibration stress by approximating the Vibration displacements measured in a noncontact manner as a primary mode. This paper presents the principles and calculation formulas of both methods and shows the measurement techniques for the bending and torsional Vibration stresses using laser displacement sensors. Finally the applicability of one method is discussed based on the results of a Vibration experiment.
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Experiment and Simulation on Pressure Pulsation Accompanied by Acoustic Resonance and Piping Vibration
Volume 4: Fluid-Structure Interaction, 2011Co-Authors: Takashi Tsuji, Akira Maekawa, Michiyasu Noda, Tsuneo A. Takahashi, Minoru Kato, Katsuhisa FujitaAbstract:To improve condition-based maintenance (CBM) techniques for operating plants, it is necessary to investigate, by experiments and numerical simulations, on the behavior of fluid inside Piping system in detail. This study was conducted using the full-scale Piping system under conditions that could seriously threaten the plant operation, by matching pressure pulsation, acoustic resonance and Piping natural frequency. Although Piping Vibration is reported to influence fluid pressure pulsation, there were few examples of such influence in the conditions of this experiment. Knowing that the opening ratio of the pressure control valve affects the boundary condition for acoustic resonance, the experiment and numerical simulation at different opening ratios were conducted. It was suggested that there are cases in which a valve partially open at 25% or less shouldn’t be taken as a closed end. This finding conflicts with widespread design assumption.Copyright © 2011 by ASME
Haribabu Locharla - One of the best experts on this subject based on the ideXlab platform.
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Inventive Resolution to Prevent Piping Vibration – A Case Study
Day 3 Wed November 14 2018, 2018Co-Authors: Haribabu Locharla, Sathyanath Narayanan, Juma Al Maskeri, Shahid Rafiq, Alya Al AhmadAbstract:Abstract Piping systems under multi-phase flow are subjected to unbalanced forces during plant operation and they experience Vibration. Usually, the Piping Vibrations can be minimized by either modifying Piping configuration/supports or alteration of operational modes. This paper presents an engineering study of a challenging Piping Vibration problem, which was resolved by an inventive and cost optimizing solution, as there are limitations in modification of existing pipe support/configuration. The inventive resolution reduced implementation cost to the Company without impacting the operations. A comprehensive study was conducted to identify the root cause of Piping Vibration in rich amine Piping system (36" pipe) from heat exchanger to amine regenerator, a tall column. The Vibration screening and likelihood-of-failure calculations were carried out based on Energy Institute's guidelines and observed that the Piping system is in concern/problem zones. The process study including review of hydraulics, verification of line size and control valve design was performed to identify the root cause of Piping Vibration. The Piping stress analysis (static/dynamic) was carried out with actual operating conditions, which is under multiphase flow with varying density/forces. The process study revealed that the flow velocity and momentum are within process design requirements. However the flow in the Piping system is multi-phase type, which generates unbalanced forces due to slug loads at each elbow of the Piping system. Based on Piping stress analysis results, it was identified that the natural frequency of Piping systems is variable as the whole weight of the vertical Piping system is resting on spring type supports, which in turn, are supported from vertical vessel cleats. These supports are provided to take care of relative displacements between vessel and vertical Piping systems. Piping configuration cannot be modified considering large bore Piping and requirement of huge structural supports. The existing supports also cannot be modified as they are connected to pressure vessel and will impact its design. In this scenario of multiple limitations, the indispensable flow induced Vibrations of Piping can only be minimized by damping the effect of flow-induced excitation with dampers. The dampers have elastic-viscous material in its main restraining body which can absorb the Piping Vibrations. The damper vendor performed the stress analysis, considering the effect of the damper in the whole Piping system, and ensured the integrity of Piping system. The challenge of maintaining existing spring supports and achieving required damping of Piping Vibration was successfully accomplished. Considering large sized Piping and requirement of major structural supports in case of modifications, proposed solutions could be treated as cost effective and innovative. Though it was not possible to eliminate the root cause, this alternate innovative solution helped to not only to minimize Vibration, but also optimize implementation/shutdown costs. Vibration damper in Piping systems is unique to Piping installations.
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Flow Induced Vibration in Multi Phase Piping Systems - Successful Mitigation
Day 2 Tue November 14 2017, 2017Co-Authors: Haribabu Locharla, Alya Al Ahmad, Ibrahim Al Awadhi, Sathyanath Narayana, Robert MirandaAbstract:Abstract Ideal process/Piping design is based on consistent and steady operating parameters. Sometimes these parameters varies significantly due to capacity or performance enhancements during operation. These flow changes from an ideal design to actual operating conditions are often resulting in flow induced Vibrations. Excessive Vibrations in Piping systems pose potential threats to plant safety and integrity. This paper presents the challenges to mitigate flow induced Piping Vibration due to multi-phase flow in rich amine systems with successful measures. A comprehensive study was conducted to identify the root cause for Piping Vibration in rich amine Piping system (20″ pipe) from plate type heat exchanger to amine regenerator. The Vibration measurement was carried out where the Vibrations are visually high. The Vibration screening and likelihood calculations were carried out based on Energy Institute's guidelines and those were identified in concern/problem zones. The process study including the review of hydraulics and Piping stress analysis was carried out with actual operating conditions. The multiphase density/forces was simulated to identify root cause and to propose suitable recommendations for mitigation of Piping Vibration. Process study reveals that the fluid flow type is multi-phase where the sudden pressure drop occurs at control valve. The flow regimes were reviewed along the section of pipe to identify the major flow turbulences. The alteration in the operational modes shall reduce the impact of load due to slug flow and shall minimize the Vibration. But, since it results in loss of energy, it was suggested to provide adequate Piping supports to mitigate the Piping Vibration. Static/dynamic Piping stress analysis reveals that the Piping system needs better supporting arrangement to cater slug loads conditions. The natural frequency of existing system was calculated and found to be low with existing supports. The design of existing supports was reviewed and accordingly suggested suitable additional supports such as holddown and axial stop to increase the natural frequency of Piping Vibration. Since the Piping Vibration source is control valve where there is sudden change in pressure, the guides and axial stop restraints were proposed to control lateral/axial movements by keeping the stresses in safe limits. The proposed modification were implemented while plant is in operation. The post implementation Vibration survey was carried out and the readings were found to be within acceptable limits. The challenges such as balancing the stresses in Piping system with appropriate minimum natural frequency levels to make system rigid enough and implementation of proposed modifications without shutdown were successfully achieved. The novel information from this study is, by identifying exact root cause of Piping Vibration, it is easy to mitigate the same from source level by application of best design/analysis practices with successful measures.
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Minimize Shaking Maximize Process Safety
Day 1 Mon November 07 2016, 2016Co-Authors: Haribabu Locharla, Sathyanath Narayanan, Ibrahim Al AwadhiAbstract:Abstract Integrity of Piping systems is critical for the safe and reliable Plant operations. Shaking or Vibration of Piping systems pose potential threats to plant safety and integrity. In GASCO plants, Vibrations were observed in some systems such as Piping carrying two-phase flow, high pressure lines, Piping associated with compressors / pumps, etc. Minimizing the pipe shaking to maximize the process safety through a systematic approach will result in economical, efficient, safe and time bound advantages. This paper presents GASCO's approach in resolving Piping Vibrations and mitigating the risks to plant operations. Studies were carried out to investigate the root cause and recommend required remedial measures. Walkthrough along the Piping system was carried out to identify locations of high Vibrations and to detect any mechanical abnormalities as first step. Process conditions were also verified for any upsets. This was followed by measurement of Vibration parameters such as amplitudes, frequencies and accelerations. The data collected was analyzed and level of Vibrations were classified as critical and non-critical based on recommended limits as per relevant industry standards. For the critical systems, detailed process studies / Piping stress analysis were carried out by simulating actual Piping Vibration taking various excitation sources and as-built conditions into consideration. Theoretical results were compared with field data and were found to be consistent. In order to limit the Vibrations within permissible values, necessary measures were recommended. Based on recommended modifications, revised Piping stress analysis was carried out to ensure Vibrations are within design limits. Implementation packages were prepared to execute the suggested remedial measures. Post-implementation Vibration measurements were taken and observed to be comparable to design values and within permissible limits, thereby ensuring plant safety and integrity. Less attention paid to Piping Vibration during initial design phase, probably due to lack of clear and precise codes and standards, was found to be the main reason for Piping Vibrations. GASCO recognized the need for documenting the above best practices to address Piping Vibrations. The Guidelines are developed to identify/classify the severity of Vibrations and the way forward to tackle the Piping Vibration issues which can be used by site personnel.
Michael Oliver - One of the best experts on this subject based on the ideXlab platform.
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Farley Main Steam Flow-Induced Vibration Investigation
Thermal Hydraulic Problems Sloshing Phenomena and Extreme Loads on Structures, 2002Co-Authors: Gregory Zysk, Michael OliverAbstract:Piping Vibration had been observed in the Farley Unit 2 main steam system since plant start-up. Hanger damage occurred in several portions of the system, including inside containment, in the Main Steam Valve Room (MSVR), and in the turbine building. A program was undertaken to determine the cause of the failures in the main steam supports. This program included the installation of diagnostic equipment, data analysis, and acoustic and structural modeling in an effort to determine the root cause of the Piping Vibration. The program also addressed a modified system support scheme, which included the addition of Vibration absorbing and dampening devices. Recommendations were also provided to resolve the Vibration issue.Copyright © 2002 by ASME