• Journal of the Korean Society for Precision Engineering
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• v.32 no.11
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• pp.997-1005
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• 2015

In this study, modal analysis and equivalent static load analysis for valve supports of 26" gas piping in gas stations were conducted and the existing straight and inclined types of valve supports were compared using seismic performance testing. Also, a new valve support shape was suggested by optimizing position of fastener holes, width and thickness of the support, and size of bracket. Improvement in seismic performance by design optimization was verified through equivalent static load analysis. The seismic performance of the newly proposed valve support was greatly improved and the maximum displacement and maximum stress of the seismic load was about 20% lower than those of the existing valve support.

• Journal of the Korean Society of Safety
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• v.32 no.6
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• pp.75-80
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• 2017

In this study, seismic performance of various types of valve supports in terms of flexural rigidity are evaluated by FEA using equivalent static load method. Flexural rigidity of the existing two types of valve supports can be effectively improved by simply adding one more bracket on the other side of support. New types of polygonal valve supports with a concept of fully stressed beam theory are suggested and it is verified that the new supports are rigid enough to withstand stronger earthquake which we should be prepared for.

• Journal of the Korean Institute of Gas
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• v.17 no.2
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• pp.70-77
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• 2013

The present study has been carried out to analyze the effect of steam hammering on the steam piping system including the final superheater, the high pressure turbine, check valve and the first reheater by sudden stoping of main stop valve in a power plant. For the present steam hammering analysis, the well known Flowmaster software has been used to model the steam piping system and the time dependent characteristics of pressure and steam mass flow rate has been conducted. Using the result of the unsteady pressure and steam mass flow rate, the forces acting on the elbows in the piping system has been derived. From the present analysis, it has been elucidated that the elbow just before the main stop valve and the elbow near the connection pipe between bypass pipe and check valve had the largest force among the elbows in the steam piping system. The structural safety diagnostics study on the elbow and the supporting structures of the steam piping system of a power plant will be conducted in the future by the present results of the forces acting on the elbow.

• Journal of the Korean Society of Safety
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• v.32 no.1
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• pp.60-65
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• 2017

In this study, a simplified FE model for evaluating seismic performance of valve support was suggested and an apparatus for a real structure testing was developed. The seismic performances of three different types of valve supports were evaluated by the real structure testing. By comparing the results between the real structure testing and FEA using the simplified FE model, it was verified that the suggested simplified FE model can be utilized for comparative evaluation of seismic performance of valve supports.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.145-150
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• 2017

In this study, among the various types of plant equipment, valves, which are susceptible to water hammer, were selected as the diagnosis target. In order to effectively measure the vibration, an accelerometer was adapted for use in this difficult environment. The results showed that the maximum peak-to-peak vibration displacement caused by the action of water hammer on the valve was 21.40 mm, which would affect the structural stability of the valve and pipe. Meanwhile, the measured data was applied to the HIL simulator to verify the reproduction of the vibration. In the future, field data will be applied to the HIL simulator for the purpose of assessing the fatigue, durability and expected residual life of the plant equipment.