What is the difference between a floating ball valve and a fixed ball valve?

1. Floating ball valve: The ball in this type of valve is floating; under the pressure of the medium, the ball can move to a certain extent and press against the sealing surface at the outlet, thereby ensuring proper sealing at that outlet. 　　The floating ball valve has a simple structure and good sealing performance. However, all the load exerted by the working medium on the ball is transferred to the outlet seal, so it is necessary to consider whether the material of the seal can withstand the working load from the medium. Under high pressure impacts, the ball may shift. This structure is generally used in medium and low pressure ball valves. 　　2. Fixed ball valve: The ball in this type of valve is fixed and does not move under pressure. Fixed ball valves are equipped with floating valve seats; under the pressure of the medium, these seats move, causing the sealing ring to press tightly against the ball in order to ensure a tight seal. Bearings are usually installed on the upper and lower axes of the sphere, resulting in low operating torque; it is suitable for high-pressure and large-diameter valves. 　　To reduce the operating torque of ball valves and improve the reliability of sealing, oil-sealed ball valves have emerged in recent years. These valves inject a special lubricant between the sealing surfaces to create an oil film, which not only enhances the sealing performance but also reduces the operating torque; they are thus more suitable for high-pressure, large-diameter ball valves.