Fluid structure interaction (FSI) study at the small bore connection (SBC) due to water hammer: article

Water hammer is one of the serious problem that commonly occur in the piping system. Occurrence of this problem can cause physical damage to the pipe and in worst condition, leak will happen and cause burst. The main critical area in this problem is small bore connection which can give negative impact to the structural of pipe. According to definition of water hammer, this problem normally happen when there are changes in fluid velocity caused by sudden closure or opening of pump and valve or electrical failure. In this study, an analysis by using ANSYS Workbench had been done at mainline pipe that have various diameter size of small bore connection. Diameter of small bore connection are varies from 1 inch (25.4 mm) to 2 inch (50.8 mm). The purpose of this study is to find maximum pressure distribution in the pipe. Result shows that maximum pressure distribution inside the pipe is increased when diameter of small bore connection increased for both simulations using different pressure and velocities. Pressure at the point 318 mm from the inlet shows the highest pressure compared to other point. In addition, the study investigated the effect of water hammer on small bore piping by utilizing Finite Element Analysis (FEA). Through this study, the effect that occur on the structure of small bore piping can be expected on certain pressure data. Based on the result if the maximum stress and strain of pipe simulation exceed the maximum stress and strain of carbon steel, small bore piping will deform. From the result analysis that obtained by concluding both objective, it found that the maximum pressure distribution occurred at inlet pressure 4826330 Pa and at inlet velocity 12 m/s at the flange termination. Maximum deformation also occurs at 1 inch small bore connection with these pressure and velocity.