Plasma sprayed ceramic and cermet coatings have been widely used as protective layer of machine parts and pressure-containing components due to their good abrasion resistance,corrosion resistance and heat resistance.The ball valves used in the reforming catalyst regeneration system in petrochemical plants operate usually under the rigorous conditions of elevated temperature,high pressure and mill dust.The gas-solid mixture with high hardness Al2O3 powder induces dny friction of the contact surface between valve ball and seat,and causes excessive wear and scuffing of the sealing surface,which results in failure of ball valves finally.To increase wear resistance of the sealing surface is an effective means for elongating the lifespan of ball valves in order to improve the operating safety and stability of the reforming catalyst regeneration system.