The sealing is good, but the load of the ball to the working medium is transmitted to the outlet sealing ring. Therefore, it is necessary to consider whether the sealing material can withstand the working load of the spherical medium. When subjected to high pressure impact, the sphere may be offset. . This structure is generally used for medium and low pressure ball valves.
The ball of the ball valve is fixed and does not move after being pressed. The fixed ball valve has a floating valve seat. After the medium pressure, the valve seat moves, so that the sealing ring is pressed against the ball to ensure the seal. Usually mounted on the upper and lower shafts of the ball, the operating torque is small, 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, an oil seal ball valve has appeared, which injects a special lubricating oil between the sealing faces to form an oil film, which enhances the sealing performance and reduces the operating torque. Suitable for high pressure and large diameter ball valves.