A ball valve uses a ball as the closing element. It primarily consists of a valve body, valve seat, ball, stem, and handle (or other actuating device, such as an electric, pneumatic, or hydraulic actuator). Driven by the valve stem, the ball valve rotates about its axis. It is primarily used to cut, distribute, and redirect the flow of media in pipelines.

There are many different types of ball valves, depending on their operating principles, media, and application locations. Users should select the appropriate type of ball valve based on the specific application conditions. Ball valve types are categorized based on the following structural types:

1. Floating Ball Valve

The ball of a ball valve floats. Under the pressure of the media, the ball can move a certain distance and press against the sealing surface at the outlet, ensuring a tight seal.

Floating ball valves offer a simple structure and excellent sealing performance. However, the load of the working media on the ball is entirely transferred to the outlet sealing ring, so the ability of the sealing ring material to withstand the working load of the media must be considered. This structure is widely used in medium and low-pressure ball valves.

2. Trommel Ball Valve

The ball of a ball valve is fixed and does not move under pressure. Trommel ball valves all have floating seats. Under medium pressure, the seats move, pressing the sealing ring against the ball to ensure a tight seal. Bearings are usually installed on the upper and lower shafts of the ball, resulting in low operating torque and suitable for high-pressure and large-diameter valves.

To reduce the operating torque of ball valves and increase the sealing reliability, oil-sealed ball valves have recently emerged. These valves use a special lubricant injected between the sealing surfaces to form an oil film, enhancing sealing while reducing operating torque, making them more suitable for high-pressure and large-diameter ball valves.

3. Elastic Ball Valve

The ball of a ball valve is elastic. Both the ball and the seat are made of metal. The sealing pressure is very high, and the sealing requirements cannot be met under the pressure of the medium itself, requiring external force. This type of valve is suitable for high-temperature and high-pressure media.

Elastic balls are made of elastic grooves on the lower end of the inner wall of the ball to achieve elasticity. When closing the passage, the wedge-shaped head on the valve stem expands the ball and presses it against the valve seat to achieve a seal. Loosening the wedge-shaped head before rotating the ball will cause the ball to return to its original shape, creating a small gap between the ball and the valve seat, reducing friction on the sealing surface and operating torque.

Common ball valve classification methods include the following:

By flow path type: full-bore ball valve, reduced-bore ball valve

By channel position: straight-through, tee, right-angle

By temperature range: high-temperature ball valve, normal-temperature ball valve, low-temperature ball valve, ultra-low-temperature ball valve

By sealing type: soft-seal ball valve, hard-seal ball valve

By stem assembly: top-entry ball valve, side-entry ball valve

By connection type: flanged ball valve, welded ball valve, threaded ball valve, clamp ball valve

By actuation method: manual ball valve, automatic control ball valve (pneumatic ball valve, electric ball valve, hydraulic ball valve)

By diameter: extra-large diameter ball valve, large diameter ball valve, medium diameter ball valve, small diameter ball valve