A quick overview of the knowledge about ball valves (part one)

Industry News

Posted: 03/21/2019 13:58:17 Hits: 33

A ball valve is mainly used in the pipeline to cut, distribute the flow and change the flow direction of the medium. It can be closed tightly by only a small torque and being rotated 90 degrees. The ball valve is most suitable for use as a switch or shut-off valve. Ball valves were introduced in the 1950s. With the rapid development of science and technology, the continuous improvement of production technology and product structure, ball valve has rapidly developed into a major valve category in just 50 years.

Since ball valves typically use rubber, nylon, and Teflon as the seat seal material, their service temperature is limited by the material of the seat seal. The cut-off function of the ball valve is achieved by the metal ball being pressed against the plastic valve seat under the action of the medium (floating ball valve). The valve seat seal is deformed by elastic deformation in a local area under certain contact pressure. This deformation can compensate for the manufacturing precision and surface roughness of the sphere and ensure the sealing performance of the ball valve.

Also because the seat seal of the ball valve is usually made of plastic, in the structure and performance of the ball valve, the fire resistance and fireproof of the ball valve should be considered, especially in the petroleum, chemical, metallurgical and other industries. One should pay more attention to fire protection when using ball valves in equipment and piping systems with a flammable and explosive medium.

Classification of ball valves
Ball valves can be divided into floating ball valve, trunnion ball valve, track ball valve, V-shaped ball valve, three-way ball valve, stainless steel ball valve, cast steel ball valve, forged steel ball valve, dust discharging ball valve, anti-sulfur ball valve, welded ball valve. In addition, according to the function and transmission form, it can be classified to air ball valve, bypass ball valve, pressure-release ball valve, drainage ball valve, or pneumatic ball valve, electric ball valve, hydraulic ball valve, pneumatic hydraulic ball valve, electric hydraulic ball valve, turbo driving ball valve.

Characteristics of ball valves
1. It has the lowest flow resistance (actually zero).
2. The ball valve will not get stuck when there is no lubricant, so it can be reliably applied to corrosive media and liquids with a low boiling point.
3. A 100% sealing performance can be achieved over a wide range of pressures and temperatures.
4. It can realize ultra-fast opening and closing. The opening and closing time of some structures is only 0.05-0.1s, which can be used in the automation system of the test bench. When the valve is quickly opened and closed, the operation is shock-free.
5. The ball-type closing member can be automatically positioned.
6. The working medium is sealed reliably on both sides.
7. When fully open or fully closed, the sealing surface of the ball and the seat is isolated from the medium, so the medium that passes through the valve at high speed does not cause erosion of the sealing surface.
8. Ball valves are compact and lightweight, can be considered as the most reasonable valve structure for low temperature media systems.
9. The valve body is symmetrical, when welded to the valve body structure, it can withstand the stress from the pipe well.
10. The closing member can withstand the high pressure difference at the time of closing.
11. Ball valves with all-welded valve body can be buried directly in the ground, so that the valve internals are not eroded. The maximum service life can reach 30 years, it is the most ideal valve for oil and natural gas pipelines.

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Next: A quick overview of the knowledge about ball valves (part two)

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Teresa

Teresa is a skilled author specializing in industrial technical articles with over eight years of experience. She has a deep understanding of manufacturing processes, material science, and technological advancements. Her work includes detailed analyses, process optimization techniques, and quality control methods that aim to enhance production efficiency and product quality across various industries. Teresa's articles are well-researched, clear, and informative, making complex industrial concepts accessible to professionals and stakeholders.