Introduction to the Full Bore Ball Valves
The diameter of a full bore ball valve
refers to the universal diameter of various pipes and pipeline accessories. Pipes and pipeline accessories of the same diameter can be connected to each other and have interchangeability. Although its value is relatively close to or equal to the inner diameter of the pipeline, it is not the actual outer diameter or inner diameter of the pipeline. In process pipeline systems, most valves
are designed to limit the flow of closed components to a certain range by making the flow channel or area smaller than the inner diameter of the pipeline. Some ball valves can be designed with sufficient internal flow channels to allow logistics to pass without obvious restrictions. This type of ball valve is called a full bore ball valve because its internal flow channel is equal to the full area of the inlet. Full bore ball valves are mainly used for switch and circuit breaker conditions.
Reduced bore ball valves are valves that control flow through closed components. The flow area of the opening of the closed component is smaller than the area of the inner diameter of the pipeline. The main purpose of a reduced bore ball valve is to control flow by reducing or intercepting flow, which is equivalent to adjusting the closed element to provide different flow rates at a certain opening of the valve. The main difference between full bore ball valves and reduced bore ball valves is that the full bore ball valve has an equal width flow passage, and its size cannot be less than the standard specified value, which is approximately equivalent to the nominal diameter of the specification. For example, the flow passage diameter of a DN50 full bore ball valve is about 50mm. The inlet of the reduced diameter ball valve is wider than the diameter of the flow channel, and the actual diameter of the flow channel is approximately one specification smaller than this specification. For example, when a DN50 reduced bore ball valve flows to a diameter of about 38, it is roughly equivalent to the size of DN40. The key is that its diameter should be consistent with its nominal specification, not just the channel unchanged, so your second understanding is correct.
The working principle of ball valves: ball valves are valves that are driven by the valve stem and rotate around the shaft. It can also be used for fluid regulation and control, with hard sealed V-shaped ball cores and hard alloy valve seats having high shear forces, especially suitable for media containing fibers, small solid particles, etc. Multiway ball valves can not only flexibly control the convergence, diversion, and switching of medium flow in pipelines, but also close any channel and connect the other two channels. It's generally installed horizontally in pipelines.
What are the advantages of ball valves?
1. Thrust bearings can reduce the friction torque of the valve stem, making it stable and flexible for long-term operation.
2. Anti-static function: there is a spring between the ball, valve stem, and valve body, which can remove static electricity generated during the switching process.
3. Due to the excellent self-lubricating performance of materials such as Teflon, the friction loss with the ball is small, and the service life is long.
4. Low fluid resistance: ball valves have the lowest fluid resistance among all valve types. Even small-sized pneumatic ball valves have relatively small fluid resistance.
5. Reliable sealing of the valve stem: due to the fact that the valve stem only rotates without lifting, the valve stem packing seal is not easily damaged, and the sealing capacity increases with the increase of medium pressure.
6. Good sealing performance of the valve seat: the sealing ring made of elastic materials such as Teflon is easy to seal, and the sealing ability of pneumatic ball valves increases with the increase of medium pressure.
7. Low flow resistance. Full bore ball valves are without flow.
8. Simple structure, small size, and light weight
9. Tight and reliable. It has two sealing surfaces, and the sealing surface material of the ball valve is widely used with various plastics, which have good sealing performance and can achieve complete sealing. It has also been widely used in vacuum systems.
10. It's easy to operate and quick to open and close. It can rotate 90 degrees from open to close for remote control.
11. Convenient maintenance, simple structure, and the sealing ring is usually movable. It's easy to disassemble and replace.
12. When fully opened or fully closed, the sealing surface of the ball and valve seat separates from the medium. When the medium passes through, it will not cause corrosion on the valve sealing surface.
13. It has a wide range of applications, ranging from small diameters to a few millimeters, to several meters, and it can be applied from high vacuum to high pressure.
14. Due to its wiping performance during opening and closing processes, it can be used in suspended media.
15. High processing accuracy and high cost. It's not suitable for high temperatures. If there are impurities in the pipeline, it is easy to be blocked by impurities, causing the valve to fail to open.