Classification of Ball Valves

2022-06-21

According to the structure:

1. Floating ball valve

The ball of the ball valve is floating. Under the medium pressure, the ball can produce a certain displacement and press tightly on the sealing surface of the outlet end to ensure the sealing of the outlet end. The structure of floating ball valve is simple and its sealing performance is good, but the load of working medium bore by the ball is all transmitted to the outlet sealing ring, so it is necessary to consider whether the sealing ring material can withstand the working load of the ball medium. This structure is widely used in medium and low pressure ball valves.

2. Trunnion mounted ball valve

The ball of the ball valve is fixed and does not move under pressure. Fixed ball valves are equipped with floating seats. Under the pressure of medium, the seats move to make the sealing ring tightly press on the ball to ensure the sealing. Bearings are usually installed on the upper and lower shafts of the ball, with small operating torque, suitable for high-pressure and large-diameter valves. In order to reduce the operating torque of ball valve and increase the availability of sealing, oil-sealed ball valve has appeared in recent years. Special lubricating oil is injected between sealing surfaces to form an oil film, which not only enhances the sealing performance, but also reduces the operating torque. It is more suitable for high-pressure and large caliber ball valve.