This document discusses the computational fluid dynamics (CFD) analysis of flow through a butterfly valve. It aims to determine the head loss coefficient and flow coefficient for the valve at different opening angles (30°, 60°, 75°, 90°). The CFD software ANSYS ICEM was used to model the valve geometry and ANSYS CFX was used to simulate the flow. The results found that the velocity increased with opening angle while head loss coefficient decreased. Streamlines became more uniform at higher openings. Numerical results closely matched experimental data, validating the CFD analysis method. The study provides a less expensive and time-consuming alternative to experimental testing of large butterfly valves.