Structure of ball valve

Structure of ball valve

The sealing performance is good, but the load of the working medium borne by the ball is transferred to the outlet sealing ring. Therefore, whether the sealing ring material can withstand the working load of the ball medium should be considered. When it is impacted by high pressure, the ball 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. Fixed ball valves are equipped with floating valve seat. Under the pressure of medium, the valve seat moves to make the sealing ring tightly press on the ball to ensure the sealing. Generally, bearings are installed on the upper and lower shafts of the ball, and the operating torque is small. It is suitable for high-pressure and large-diameter valves.

In order to reduce the operation torque of ball valve and increase the reliability of sealing, oil sealed ball valve appears again. Special lubricating oil is injected between the sealing surfaces to form a layer of oil film, which enhances the sealing performance and reduces the operation torque. It is more suitable for high pressure and large diameter ball valve.