The sealing performance is good, but the load of the sphere bearing the working medium is all transferred to the outlet sealing ring. Therefore, it is necessary to consider whether the material of the sealing ring can withstand the working load of the sphere medium. When subjected to high pressure shock, the sphere may shift. . This structure is generally used for medium and low pressure ball valves.

The ball of the ball valve is fixed and does not move under pressure. The fixed ball valve has a floating valve seat. After being pressurized by the medium, the valve seat moves, so that the sealing ring is tightly pressed on the ball to ensure the sealing. Bearings are usually installed on the upper and lower shafts with the ball, and the operating torque is small, which is suitable for high-pressure and large-diameter valves.

In order to reduce the operating torque of the ball valve and increase the reliability of the seal, oil-sealed ball valves have appeared, which not only inject special lubricating oil between the sealing surfaces to form an oil film, which not only enhances the sealing performance, but also reduces the operating torque. Suitable for high pressure and large diameter ball valves.