International Journal of Trend in Research and Development, Volume 2(6), ISSN 2394-9333 www.ijtrd.com IJTRD |Nov-Dec 2015 Available Online@www.ijtrd.com 39 Performance Parameters of Butterfly Valve - A Review Girish B. Pawar 1 , Pramod Suryawanshi 2 , Akshay Shinde 3 , Onkar Vade 4 1 Assistant Professor, 2,3,4 U.G. Student, Department of Mechanical Engineering, Annasaheb Dange College of Engineering & Technology, Ashta, Maharashtra, India Abstract - Butterfly Valves are commonly used in industrial applications to control the internal flow of both compressible and incompressible fluids. A butterfly valve typically consists of a metal disc formed around a central shaft, which acts as its axis of rotation. As the valve's opening angle is increased from 0 degrees (fully closed) to 90 degrees (fully open), fluid is able to more readily flow past the valve. Characterizing a valve's performance factors, such as pressure drop, hydrodynamic torque, flow coefficient, loss coefficient, and torque coefficient, is necessary for fluid system designers to account for system requirements to properly operate the valve and prevent permanent damage from occurring. This comparison study of a butterfly valve's experimental performance factors is done using Computational Fluid Dynamics (CFD), CFD was able to appropriately predict common performance factors for butterfly valves. Keywords- Pressure drop, Hydrodynamic Torqe, Flow Coefficient, Torqe Coefficient,CFD. I. INTRODUCTION Butterfly valves are commonly used as control valves in applications where the pressure drops required of the valves are relatively low. Butterfly valves can be used in applications as either shut off valves (on/off service) or as throttling valves (for flow or pressure control). As shut off valves, butterfly valves offer excellent performance within the range of their pressure rating. Typical uses would include isolation of equipment, fill/drain systems, bypass system and other like applications where the only criteria for control of the flow/pressure is that it be on or off. Although butterfly valves have only a limited ability to control pressure or flow, they have been widely used as control valves because of the economics involved. The control capabilities of a butterfly valve can also be significantly improved by coupling it with an operator and electronic control package. Butterfly valves allow high flows with relatively low pressure loss from the valves, and are typically used for flow control for valve openings from 30 to 70 degrees of full open. At valve openings greater than 70 degrees, the pressure loss of a butterfly valve is too low to produce any significant effect on flow or the energy loss of a flow system. Two special applications for a butterfly valve include the use of a valve for free discharge and the use of a butterfly valve for flashing or choking cavitation service. Free discharge typically produces high pipe velocities at moderate pressure drops, and choking cavitation typically produces high velocities with large pressure drops. II. LITERATURE REVIEW Adam Del Toro [1]stated that as the valve's opening angle is increased from 0 degrees (fully closed) to 90 degrees (fully open) fluid is able to more readily flow past the valve. Characterizing a valve's performance factors, such as pressure drop, hydrodynamic torque, flow coefficient, loss coefficient, and torque coefficient, is necessary for fluid system to account for system requirements to properly operate the valve and prevent permanent damage from occurring. an optimization procedure of the valve disc is applied in order to reduce the weight of the disc as well as to keep the stress and pressure loss coefficient in the allowable range. Ghaleb Ibrahim et.al [2] discussed that the Numerical analysis technique has become popular and reliable method in design of butterfly valves. It is possible to visualize and observe the flow characteristics around the valve and to estimate its performance. A numerical simulation for flow of water past over a butterfly valve using commercial fluid dynamics software FLUENT, has been implemented. In the analysis, the positions of the disk were set to be 0° (fully opened), 20°, 30°, 55° and 75°. Velocity profile, pressure distribution, turbulence kinetic energy and turbulence intensity are the parameters used to present the characteristic of flow. From the results obtained, turbulence in flow starts at the edges of valve disc and gets growing according to the specified case. These vortices and circulation region are generated always in downstream region behind the valve disc. They are formed due to contact between higher and lower velocities paths. It was found that the flow has a small effect with increasing closing angle till it reaches 55°, where the flow around the valve started to become highly turbulent. S. Y. Jeons et.al [3] manufactured the butterfly valves in various shapes but a fitting performance comparison is not made up. For this reason, they carried