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Ball valve is currently the most widely used mechanical product in all valve markets. It is mainly composed of valve body, valve seat, ball, valve stem and transmission device. The ball core is driven to rotate through the actuator to achieve the function of switching or adjusting. . In the chemical, environmental protection, water treatment, urban construction, machinery, and food industries, it is widely used and very popular!

There are many types of ball valves, which are connected by structural forms. Different pressure levels, drive forms, etc., can be combined into various products with different functions, but from the most basic point of view, ball valves are divided into two major categories: full-diameter ball Didlink valves and reduced-diameter ball valves. Generally speaking, when the inner diameter of the valve ball is less than or equal to 85% of the inner diameter of the ball valve port, it is called a reduced diameter ball valve, and 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-diameter ball valve. So what is the difference between the two in selection or application?

一definition：

1.     The full-bore ball valve has equal-width flow passages, that is to say, the size of the orifices from the inflow to the outflow is the same, and the size cannot be less than the value specified by the standard, which is roughly equivalent to the nominal diameter of the specification, such as DN50 full-bore ball valve The flow path diameter also needs to be about 50;

2.     2, the inlet of the reduced diameter ball valve flow path is wider than the flow path diameter, and the actual diameter of the flow path is probably smaller than this specification-a specification, such as DN50 reduced diameter ball valve flow to a diameter of 38 It is roughly equivalent to DN40 specifications. Shrink one specification within DN250 and two specifications within 250-600. Above 600 depends on actual conditions.

二Applicable medium：

1. Full-bore ball Didlink valve-generally used for conveying viscous and slagging medium pipelines. Because of its low fluid resistance, it can be said that there is basically no flow resistance, which can facilitate the passage of regular wax scrapers.

2. The reduced-diameter ball valve is suitable for pipelines that transport gases or media with physical properties similar to water, because its weight is about 30% lighter than a full-diameter ball valve, and its flow resistance is only the same diameter.About 1/7 of the check valve. It is helpful to reduce the pipeline load and reduce the cost.

三Applicable process

1. For pipelines that need to be pigged regularly, no matter what medium is transported, full-bore ball valves must be used. The medium will not reduce the flow through the full-bore ball Didlink valve, and the flow resistance is small as a pipeline

Ideal product for control, especially for demanding conditions. Especially when the main line in the oil pipeline and gas pipeline needs to be buried underground, full-diameter welded ball valves must be used.

2. Reduced diameter ball valve is suitable for some working conditions such as low requirements and small convection resistance. When the inner diameter of the valve is more than 80% greater than the inner diameter of the pipe end, it has almost no effect on the pipe fluid passing capacity. very

Many valves have reduced diameters, generally controlled within 0 8. The reduced diameter reduces the flow capacity of the valve, that is, the Kv value of the valve, increases the pressure drop at both ends of the valve, and causes energy loss.

For the pipeline, it does not have much impact, and may increase the erosion of the pipeline.

四Comparison of advantages and disadvantages

1. Installation space: The reduced diameter ball valve has a small volume, so its installation space requirements are smaller. Because its weight is about 30% lighter than a full-bore ball valve, it is beneficial to reduce pipeline load and reduce transportation burden.

He, reduce costs.

2. Cost: Reduced-diameter ball valves are one grade lower than full-diameter ball valves. Considering the cost performance, it is generally accepted internationally that adjacent pipe diameters use the same ball-diameter valve body. Such as dn32 and dn40. dn50 and

dn63, dn90 and dn110. dn160 and dn200, dn250 and dn315 use the same sphere.

Note: Since the inner diameter of the reduced diameter ball valve is small, the torque on the valve stem is small, which is more suitable to extend the service life of the valve switch. Especially the low torque design of large diameter valves. But the diameter cannot be reduced

A lot, otherwise the system resistance will increase. However, if the diameter is not reduced, the purchase cost will be increased. In addition, the valve control characteristics will generally be reduced. The adjustment effect will be worse. For example, if the control valve is always

Use at a small opening will reduce the service life of the valve.