There are two types of valves: full bore ball valve and reduced bore ball valve. Generally, when the inner diameter of the ball valve is less than or equal to 85% of the inner diameter of the ball valve port, it is called a reduced bore ball valve. When the inner diameter of the ball valve is greater than 95% of the inner diameter of the ball valve port, it is called a full bore ball valve.
1、 Definition
1.1 Full bore ball valves have equal width channels, that is to say, the size of the channel from the inlet to the outlet is the same, and its size cannot be less than the value specified in the standard, which is roughly equivalent to the nominal diameter of this specification. For example, the channel diameter of DN50 full bore ball valves should also be about 50;
2.1. The inlet of the reducing ball valve channel is wider than the diameter of the channel, and the actual diameter of the channel is about one size smaller than the size. For example, the diameter of the DN50 reducing ball valve channel is about 38, which is roughly equivalent to the size of DN40. One specification shall be reduced within DN250, two specifications shall be reduced between 250-600, and 600 or more shall be subject to the actual situation.
2、 Media
1. The full bore ball valve is generally used to transport viscous and slagging media on the pipeline. Because of its small fluid resistance, it can be said that there is basically no flow resistance, which can facilitate the passage of regular wax scraping blowers.
2. The reduced diameter ball valve is suitable for pipelines conveying gas or media with physical properties similar to water, because its weight is about 30% lighter than the full diameter ball valve, and its flow resistance layer is about 1/7 of that of the globe valve with the same diameter. It is conducive to reducing pipeline load and cost.
3、 Process
1. For pipelines requiring regular pigging, full bore ball valves must be used no matter what medium is conveyed. The medium passing through the full bore ball valve will not reduce the flow, and the small flow resistance is an ideal product for pipeline control, especially under strict working conditions, especially when the main pipelines in oil and gas pipelines need to be buried underground, the full bore welded ball valve must be used.
The reduced diameter ball valve is applicable to some working conditions with low requirements and small flow resistance requirements. When the inner diameter of the valve is more than 80% of the inner diameter of the pipe end, it has little impact on the pipeline fluid passing capacity. Many shutters have a diameter reduction, which is generally controlled within 0.8. On the one hand, the diameter reduction reduces the flow capacity of the valve, that is, the K value of the valve, increases the pressure on both sides of the valve, resulting in energy loss. It has little impact on the pipeline, perhaps increasing the flushing of the pipeline.
