Ball valves have been widely used in various sectors such as petroleum, chemical, power generation, papermaking, atomic energy, aviation, rockets, and people's daily lives.

Ball valves can be divided according to their structural form

One
Floating ball valve

The ball of a ball valve is floating, and under the pressure of the medium, the ball can produce a certain displacement and tightly press on the sealing surface of the outlet end, ensuring the sealing of the outlet end.

The floating ball valve has a simple structure and good sealing performance, but the ball bears all the load of the working medium and is transmitted to the outlet sealing ring. Therefore, it is necessary to consider whether the sealing ring material can withstand the working load of the ball medium. This structure is widely used for medium and low pressure ball valves.

Two
Fixed ball valve

The ball of a ball valve is fixed and does not move under pressure. Fixed ball valves are equipped with floating valve seats. When subjected to medium pressure, the valve seat moves, causing the sealing ring to tightly press against the ball to ensure sealing. Usually, bearings are 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 valves and increase the reliability of sealing, oil sealed ball valves have emerged in recent years. They not only inject special lubricating oil between the sealing surfaces to form a layer of oil film, which enhances sealing performance but also reduces operating torque, making them more suitable for high-pressure large-diameter ball valves.

Three
Elastic ball valve

The ball of a ball valve is elastic. Both the sphere and valve seat sealing ring are made of metal materials, with a high sealing pressure ratio. The pressure of the medium itself cannot meet the sealing requirements, and external forces must be applied. This type of valve is suitable for high-temperature and high-pressure media.

An elastic sphere is obtained by opening an elastic groove at the lower end of the inner wall of the sphere. When closing the channel, use the wedge-shaped head of the valve stem to expand the ball and compress the valve seat to achieve sealing. Before rotating the ball, loosen the wedge head, and the ball will return to its original shape, creating a small gap between the ball and the valve seat, which can reduce the friction and operating torque of the sealing surface.

Ball valves can be divided into straight through, three-way, and right angle types according to their channel positions. The latter two types of ball valves are used for distributing media and changing the flow of media.