• 한국유체기계학회 논문집
• /
• 제11권2호
• /
• pp.20-28
• /
• 2008

Recently, butterfly valves are used as control valves for industrial process. However, there are not so many reports on cryogenic butterfly valves in spite of broad application in LNG storage station and LNG carriers. Present study is focused on the investigation of the detailed hydrodynamic and aerodynamic characteristics of cryogenic butterfly valves to contribute to the operation during the handling on LNG transportation system, and to the practical utilization in design of butterfly valves and actuators. The results show that large recirculation vortices in the region downstream of the valve are founded and the cavitation flows are intensively generated on the surface of valve disc at the relatively small opening angle. The aerodynamic characteristics, lift, drag and torque, acting on the valve disc are calculated. The pressure distribution and the pressure loss coefficient of the cryogenic butterfly valve show almost similar pattern with those of the butterfly valve which is used on the normal temperature.

• 한국기계가공학회지
• /
• 제6권2호
• /
• pp.41-46
• /
• 2007

Butterfly valves are commonly used as control valves in applications where the pressure drops required of the valves relatively low. As the shutoff valve (on/off service) or throttling valves (for flow or pressure control), the higher order and the better precision of butterfly valves are required. The it's more and more essential to know the flow characteristic around the valve. Due to the fast progress of the flow visualization and numerical technique, it becomes possible to observe the flows around a valve and to estimate the performance of a valve. Researching these results did not gave only access to understand the process of the valve flows at different valve opening angles, but also was made to determine the accuracy of the employed method. Furthermore, the results of the three-dimensional analysis can be used in the design of butterfly valve in the industry.

• International Journal of Fluid Machinery and Systems
• /
• 제10권1호
• /
• pp.40-46
• /
• 2017

Small valves including ball valves, gate valves and butterfly valves have been adopted in the fields of steam power generation, petrochemical industry, carriers, and oil tankers. Butterfly valves have normally been applied to fields where in narrow places installing the existing valves such as gate valves and ball valves have proven difficult due to the surrounding area and the heavier of these valves. Butterfly valves are used to control the mass flow of the piping system under low pressure by rotating the circular disk installed inside. The butterfly valve is benefitted by having simpler structure in which the flow is controlled by rotating the disc circular plate along the center axis, whereas the weight of the valve is light compared to the gate valve and ball valve above-mentioned, as there is no additional bracket supporting the valve body. The manufacturing company needs to acquire the performance and life test equipment, in the case of adopting the improving factors to detect leakage and damage on the seat of the valve disc. However, small companies, which are manufacturing the industrial valves, normally sell their products without the life test, which is the reliability test and environment test, because of financial and manpower problems. Furthermore, the failure mode analysis of the products failed in the field is likewise problematic as there is no system collecting the failure data on sites for analyzing the failures of valves. The analyzing and researching process is not arranged systematically because of the financial problem. Therefore this study firstly tried to obtain information about the failure data from the sites, analyzed the failure mode based on the field data collected from the customers, and then obtained field data using measuring equipment. Secondly, we designed and manufactured the performance and life test equipment which also have the real time monitoring system with the naked eye for the butterfly valves. The concept of this equipment can also be adopted by other valves, such as the ball valve, gate valve, and various others. It can be applied to variously sized valves, ranging from 25 mm to large sized valves exceeding 3000 mm. Finally, this study carries out the life test with square wave pressure, using performance and life test equipment. The performance found out that the failures from the real time monitoring system were good. The results of this study can be expanded to the other valves like ball valves, gate valves, and control valves to find out the failure mode using the real time monitoring system for durability and performance tests.

• 한국산학기술학회논문지
• /
• 제13권11호
• /
• pp.4937-4943
• /
• 2012

버터플라이 밸브는 다른 밸브에 비해 작동의 용이성으로 각종 산업에서 유량 조절을 목적으로 많이 활용되고 있다. 버터플라이 밸브를 통과하는 유량을 제어하기 위해서는 디스크 각에 따른 용량계수에 따라 유량을 제어하게 된다. 본 논문에서는 고품질 밸브 제작을 위해 성능 지표 중에 하나인 용량계수를 기존의 제품의 3D 모델을 이용하여 유동 해석 및 분석을 수행하였고 이를 검증하기 위해 용량계수 측정 장비 측정을 통해 해석의 신뢰성을 확인하였다.

• 한국유체기계학회 논문집
• /
• 제7권1호
• /
• pp.9-16
• /
• 2004

A three-dimensional numerical analysis was carried out on incompressible flows in butterfly valves by using commercial FLUENT/UNS code. Characteristics of complex flows including cavitation effect were investigated for different valve disk angles. The butterfly-valves that had different disk angles and different disk shapes were compared with each other in detail. This study focused on the flow analysis in the conventional butterfly valve and the newly designed butterfly valve in order to prevent cavitation. The newly designed valve shows great improvement on performance and endurance.

• 대한조선학회논문집
• /
• 제46권5호
• /
• pp.545-551
• /
• 2009

In naval architecture and offshore engineering, the development and a broad use has been achieved in the field of flow control valves for pipe system. Butterfly valves are also widely used for flow control, but there are not many studies for triple-eccentric butterfly valves. Moreover, if the fluid of pipeline flows in the bi-direction then it makes more complicate to adapt triple-eccentric butterfly valves to flow control. In this study, we are trying to develop a bi-directional triple-eccentric butterfly valve through sealing mechanism and stem design study. Digital mockup using 3D CAD was constructed for shape interference check and structural analysis was conducted for structural safety. Also we performed leakage test to check out the durability of the bi-directional pressure for the developed valve.

• 한국산업융합학회 논문집
• /
• 제25권2_2호
• /
• pp.279-287
• /
• 2022

Butterfly valves installed on ships use valves with up to triple offset to improve tightness. However, the triple offset valve has structural problems such as disc deformation and seat separation. Accordingly, interest in quadruple offset butterfly valves with added offset is increasing. In this study, the structural safety of the quadruple offset butterfly valve was examined through numerical analysis. In addition, we intend to evaluate the performance of the valve through flow coefficient analysis.

• 유체기계공업학회:학술대회논문집
• /
• 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
• /
• pp.573-576
• /
• 2003

In butterfly control valve, a multi-hole orifice is attached downstream of valve to stabilize flow fluctuation. The computational simulation is conducted to analyze valve flow characteristics. The results show that the velocity distribution of downstream of valve with the orifice is improved compared to non-orifice case. Test result in site is 60% reduction in vibration.

• 한국소음진동공학회논문집
• /
• 제14권2호
• /
• pp.119-127
• /
• 2004

Butterfly valves are popularly used in service in the industrial and water works pipeline systems with large diameter because of its lightweight, simple structure and the rapidity of its manipulation. Sometimes cavitation can occur. resulting in noise, vibration and rapid deterioration of the valve trim, and do not allow further operation. Thus, the monitoring of cavitation is of economic interest and is very importance in industry. This paper proposes a condition monitoring scheme using statistical feature evaluation and support vector machine (SVM) to detect the cavitation conditions of butterfly valve which used as a flow control valve at the pumping stations. The stationary features of vibration signals are extracted from statistical moments. The SVMs are trained, and then classify normal and cavitation conditions of control valves. The SVMs with the reorganized feature vectors can distinguish the class of the untrained and untested data. The classification validity of this method is examined by various signals that are acquired from butterfly valves in the pumping stations and compared the classification success rate with those of self-organizing feature map neural network.

• 한국유체기계학회 논문집
• /
• 제11권2호
• /
• pp.13-19
• /
• 2008

Butterfly valves are widely used as control valves for industrial process. For the definition of optimum configuration of the valve, wide range of related studies has been actively conducted in the case of working fluids of water or air under the normal temperature. Recently, internal flow and performance characteristics of cryogenic butterfly valve for LNG carrier take a growing interest in the field of research and development. Therefore, present study is aimed to investigate the internal flow and performance characteristics of the cryogenic butterfly valve because the study result for the valve can be hardly found at present. Part 1 of this paper describes the study result of a butterfly valve model under the condition of the normal temperature. Succeeding Part 2 of this paper will describe the internal flow characteristics of a cryogenic butterfly valve for LNG carrier. The results of Part 1 show that pressure loss coefficients and flow rate coefficients obtained by the present experiment and CFD analysis agree well each other. Moreover, internal flow visualization for the valve by CFD analysis and PIV measurement have revealed complicated flow patterns of the internal flow field in detail.