Ball valve is one of valves that have many applications in industry especially in gas delivery systems. This kind of valve is categorized in the on - off flow control valve. This study aims to investigate unusual application of ball valve to control fluid flow in industry and its destructive effect including erosion of ball and body of valve. Simulation of industrial ball valve is done using ANSYS Fluent software and effect of erosion on it is investigated in different working conditions. In this article, working condition is performed regarding 2 different concentrations for suspended particles as well as four positions of ball in different angles. We assess the effect of increased particle diameter on the rate of erosion for three diameters (3.86e-6 m , 267.45e-6 m and 531.03e-6 m) in four conditions of valve (25%, 50%, 75% and 100%) and two different concentrations of particle (3% and 6%). It is shown that rate of erosion is increased with increased particle diameters in 25%, 50% and 75% open state of valve. On the contrary, the results show that opposite rule governs complete open state. Furthermore, it is demonstrated that increase in particle diameter decreases the area of erosion in four conditions of valve.