There are many kinds of ball valves, through the structure of the form, connection, pressure level, drive form, etc., can be combined into various types of different functions of the product, but from the most basic, the ball valve has a full bore ball valves and reduced ball valves of the two major categories of the difference between the points. Generally speaking, the inner diameter of the valve ball is less than or equal to 85% of the inner diameter of the ball valve port, known as the reduction of ball valves, and the inner diameter of the ball valve is greater than 95% of the inner diameter of the ball valve port, known as the full bore ball valves. So what is the difference between the two in the choice or application?

I. Definition:

1, full bore ball valve for equal width flow path, that is to say, from the flow in to the outflow of the aperture size is the same, its size can not be smaller than the standard value, roughly equivalent to the nominal diameter of the specifications, such as DN50 full bore ball valve flow path diameter also needs to be about 50;

2, reduced ball valve runner entrance is wider than the runner diameter, the actual diameter of the runner is probably smaller than the specifications of a specification, such as DN50 reduced ball valve flow to the diameter of 38 or so, roughly equivalent to the specifications of DN40. In DN250 and shrink a specification, 250-600 shrink two specifications, 600 or more according to the actual situation.

Second, the applicable medium:

1, full bore ball valves are generally used for conveying viscous, easy slagging media pipeline, because of its small fluid resistance, it can be said that there is basically no flow resistance, can be convenient for regular scraping wax blowing through.

3, reduced diameter ball valves are suitable for conveying gases or physical properties similar to water on the pipeline, because of its weight than the full diameter ball valve is about 30% lighter, and its flow resistance is only the same calibre globe valve 1/7 or so. In favour of reducing the pipeline load, reduce costs.

Third, the applicable process:

1, for the need to regularly clear the pipeline, regardless of what kind of media, must be used full bore ball valves. Medium through the full bore ball valve will not reduce the flow, and flow resistance is small as the ideal type of pipeline control products, especially the strict requirements of the working conditions. Especially in the oil pipeline and gas pipeline in the main line needs to be buried in the ground, must use the full bore welded ball valve.

2, reduce the diameter of the ball valve is suitable for some of the requirements are not high, the flow resistance requirements of small working conditions. When the inner diameter of the valve is greater than 80% of the inner diameter of the end of the pipe, the pipeline fluid through the ability to almost no effect. Many valves have a reduced diameter, generally controlled within 0.8, reduced diameter on the one hand reduces the flow capacity of the valve, that is, the valve's Kv value, increasing the pressure drop at both ends of the valve, resulting in a loss of energy, for the pipeline, there is no great impact, perhaps increasing the scouring of the pipeline.

Fourth, the advantages and disadvantages of comparison:

1, installation space: reduced diameter ball valves are small in size, so its installation space requirements are smaller. Because its weight is about 30% lighter than the full diameter ball valve, which is conducive to reducing the pipeline load, reducing the transport load, reduce costs.

2, cost: reduced diameter ball valve than the full diameter ball valve price is lower than a grade, taking into account the cost-effective, the international common default, adjacent to the pipe diameter using the same ball valve body. Such as dn32 and dn40, dn50 and dn63, dn90 and dn110, dn160 and dn200, dn250 and dn315 with the same ball.

Note: Due to the reduced diameter ball valve valve inner diameter is smaller, the valve stem is subjected to a small torque, more suitable for extending the service life of the valve switch. Especially the low torque design of large diameter valves. But the reduction can not shrink a lot, otherwise the system resistance will increase. But if you do not reduce the diameter, for one thing, is to increase the procurement costs, and then generally reduce the valve control characteristics, so that the adjustment effect becomes worse. For example, if the regulating valve is always used in a small opening, it will reduce the service life of the valve.