Solid particle erosion is one of the most commonly encountered problems faced by the oil and gas industries during production and transportation processes. The severity of solid particle erosion is affected by multitude of factors such as particle properties, fluid flow properties and flow geometry, flow regime, and target material properties. The present work investigates the effect of particle size on solid particle erosion in gas flows. Sharp quartz particles with nominal sizes of 75, 150, 300 and 600 μm are used in this work. Particle Image Velocimeter (PIV) is used to measure the particles velocities distributions for various particle flow rates. An average particle velocity of 24 m/s is used to conduct erosion experiments for various particle sizes and two particle rates on Stainless Steel 316 at two different impact angles of 15 and 90 degrees. Comparison of measurements for two particle flow rates of approximately 0.02% and 0.002% by volumes demonstrates that increased particle flow rate can affect the carrier fluid’s flow field and change particle velocities within the carrying fluid. In the erosion experiments, the magnitude of erosion ratio increases as there is an increase in particle size. A preliminary erosion model is developed that can be used in CFD simulations of solid particle erosion for various particle sizes.