The development of ball valve applications due to change of seat material

Polytetrafluoroethylene (PTFE) is the predominant choice for ball valve seat materials due to several key factors. Firstly, PTFE is highly chemically inert, making it resistant to nearly all chemical substances it may come into contact with. This attribute ensures the durability and longevity of the ball valve. Secondly, PTFE boasts a low friction coefficient, resulting in smooth operation and reduced wear and tear on the valve components. This directly contributes to the ball valve's stable performance over time. Additionally, PTFE exhibits exceptional resistance to aging, allowing the valve to maintain its efficiency and effectiveness even after prolonged use. Moreover, PTFE offers an extensive temperature application range, further enhancing its versatility in various operating conditions. Lastly, PTFE provides excellent sealing performance, ensuring a tight and reliable closure of the valve. Overall, the remarkable properties of PTFE make it the most crucial material for the seat ring of ball valves.

The design of valve seat seals needs to take into consideration the specific physical properties of PTFE, which are characterized by a high expansion coefficient, sensitivity to cold flow, and poor thermal conductivity. To address these characteristics, careful attention must be paid to the material chosen for the valve seat seal, which often includes filled PTFE, nylon, and various other substances. However, it should be noted that if the sealing material becomes hard, particularly in situations with low pressure differences, the reliability of the seal can be compromised. This underscores the importance of selecting a suitable material that can maintain its flexibility and performance under diverse operating conditions.

Furthermore, it is worth mentioning that nitrile rubber, a type of synthetic rubber, can serve as an option for valve seat sealing material. However, it is important to note that its suitability is limited to specific media and temperature ranges. There are certain restrictions when it comes to using nitrile rubber with certain drugs. Additionally, it is necessary to ensure proper lubrication of the medium to avoid any potential jamming of the ball when synthetic rubber is employed.

Over the past decade, there has been a significant development in metal-sealed ball valves designed to meet demanding industrial requirements such as high temperature, high pressure, and strong erosion. Highly developed industrial nations, such as Germany, Italy, Spain, the Netherlands, and the United States, have continuously enhanced the structure of ball valves. As a result, fully welded body direct-buried ball valves and rising stem ball valves have been introduced, making ball valves ideal for industries requiring long-distance pipelines and oil refining equipment.

In addition, with the introduction of ball valves with large diameter (3050mm), high pressure (70MPa), and wide temperature range (-196～815℃), the technology involved in the manufacturing of ball valves has now reached new heights, providing more advanced and extensive uses for industrial businesses. Thus, the demand for ball valves continues to increase in various industries, as they have become an indispensable component in the overall industrial pipeline system.

The application of computer-aided design (CAD), computer-aided manufacturing (CAM), and flexible manufacturing system (FMS) in the valve industry has revolutionized the design and production of ball valves. This advanced technology has not only transformed the calculation method for valve design but has also significantly reduced the repetitive and tedious tasks traditionally performed by professionals. Consequently, engineers and technicians now have the ability to focus more on enhancing product performance and accelerating the development cycle of new valve models, leading to a substantial improvement in overall labor productivity.

One notable example of this progress is evident in the research and development of rising stem metal-sealed ball valves. Thanks to the implementation of CAD/CAM, engineers were able to create a meticulously designed valve stem with a spiral flat shape using computer-aided design and computer-aided numerical control machine tools. This innovation has effectively eliminated any potential scratches or wear during the opening and closing process, thereby greatly enhancing the sealing performance and prolonging the service life of these ball valves.

In summary, the integration of CAD, CAM, and FMS technologies in the valve industry has undoubtedly redefined the manufacturing landscape for ball valves. By streamlining design processes and liberating professionals from mundane tasks, these advancements have propelled the industry forward, leading to improved product quality, increased efficiency, and accelerated product development timelines.

The equal diameter ball valve is widely utilized in oil and gas pipelines due to its ability to thoroughly clean the pipeline. When fully opened, the ball valve offers minimal flow resistance, almost negligible, essentially zero. This characteristic is highly advantageous as it allows for unhindered fluid flow. The wiping action of the ball during the opening and closing process further enhances its suitability for use in media containing suspended solid particles. Moreover, depending on the material used for the sealing ring, the ball valve can also effectively handle powder and granular media.