• Proceedings of the Korean Nuclear Society Conference
• /
• 2003.10a
• /
• pp.97.2-97.2
• /
• 2003

• Proceedings of the KSME Conference
• /
• 2005.11a
• /
• pp.169.2-169.2
• /
• 2005

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2006.11a
• /
• pp.298-299
• /
• 2006

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.40 no.1
• /
• pp.81-86
• /
• 2016

The valves used to control or shut off the flow through a pipeline can be divided into many different types, including gate valves, globe valves, and check valves. Globe valves, in particular, have excellent properties, and because they can easily control the flow under high-pressure conditions, they are generally used in LNG ship and steam pipelines. In this paper, a method for changing the shape of a seat was suggested to solve the valve leakage problem from a structural perspective. In addition, the stress distribution and directional deformation were compared for each model. The suggested models were thus validated, and the optimized seat structure, which includes a self-supporting capability for decreasing the amount of leakage, was determined.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.22 no.2
• /
• pp.115-122
• /
• 2014

Injection pressure is one of factors that influence part quality. In this paper, injection pressure was minimized by optimizing valve gate locations. In order to perform design optimization, MAPS-3DTM (Mold Analysis and Plastic Solution-3D) was used for injection mold analysis and PIAnOTM (Process Integration, Automation and Optimization) was used as process integration and design optimization. Also we adapted meta models based on design of experiments for efficiency. By using introduced methodology, we were able to obtain a result so that maximum injection pressure reduced by 28% compared to the initial design. And the validity of the proposed method could also be demonstrated.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2014.05a
• /
• pp.152-155
• /
• 2014

This paper describes a design of digital PWM controller for automotive brake solenoid valve which is used in ABS/ESC SoC. The PWM controller which consists of 12 channels supports both direct control and PI control. Six channels in direct control mode make consistent PWM signals according to duty ratio setting, and the others in PI control mode make PWM signals with constant current depending on current setting. The PWM controller also has functions including solenoid valve open detection, Dither and PWM phase shift. The PWM controller having 44,779 gates is fabricated using a 0.18um CMOS process, and test results show that all the functions are correct.

• Journal of Korea Foundry Society
• /
• v.42 no.6
• /
• pp.331-336
• /
• 2022

In this study, we investigated the casting designs for fuel tank valves for LPG automobiles. The valves we studied have two cavities inside the part. There is inevitable air entrapment inside the cavities. In order to reduce this kind of casting defect, we carried out computer simulations of molten metal flow during the diecasting process of the target products. The main process parameters were the ingate position, product direction, and injection velocity. We also examined the possible use of vacuum diecasting. The position of the air entrapment was almost identical for all the ingate positions and product directions. We found that the change of the injection velocity affects the position of the air entrapment. In case of vacuum diecasting, the position of the air entrapment was similar to the previous cases, but it is expected that the air entrapment will be highly reduced in a real situation due to the vacuumed space.

• Proceedings of the KSME Conference
• /
• 2001.06a
• /
• pp.328-332
• /
• 2001

The purpose of this paper is to address the structural integrity of the stem disc T-head connection of the motor operated valve assembly by comparing the previously developed methodology with the finite element analysis(FEA). From the experiences of the previously performed weak link analysis, the most of "weak links" when valve is opened are stem-disc T-head connections, and the bearing stress on the disc is the dominant stress. The results of FEA are compared with that of the classical approaches of the weak link analysis. The higher allowable thrust be represented by performing the elastic-plastic FEA.

• 유체기계공업학회:학술대회논문집
• /
• 2003.12a
• /
• pp.562-567
• /
• 2003

This paper presents the method of Rate of Loading(ROL) improvement for the Motor Operated Gate Valve operating in high differential pressure condition. The character of ROL and Stem Factor is analyzed. Static test and dynamic test were performed and acquired the diagnosis signal for the valve closing stroke. The result of this study is the modification of stem factor is very important factor for the ROL improvement. In order to obtain the same value of dynamic test thread friction coefficient stem and stem nut should be combined appropriately.

• The KSFM Journal of Fluid Machinery
• /
• v.10 no.5
• /
• pp.20-26
• /
• 2007

Some gate valves are susceptible to pressure locking and thermal binding which prevent the safety function. The safety related gate valves susceptible to pressure locking and thermal binding shall be identified and taken preventive actions to ensure the safety function. The identification of the gate valves susceptible to pressure locking and thermal binding needs the evaluation of system design, valve and piping arrangement, test requirements, and operating conditions. Application of preventive methods should consider the system safety function, applicability, effectiveness, interface with system design, and cost. The selection procedure of valves susceptible to pressure locking and thermal binding can be effectively used in industry including nuclear power plants. In order to prevent the pressure locking, the hole can be drilled through the one disc of upstream side or down stream and the external equalizing line can be installed from bonnet to downstream or upstream. The double disc parallel seat valve type can be used instead of flexible wedge gate valve to prevent the thermal binding. The identification of gate valves susceptible to pressure locking and thermal binding, and preventive actions will meet the regulatory requirements and enhance the availability and safety of plants.