What's the difference between ball valves and plug valves?
When used for cutting off, plug valves have a slightly better regulating ability than sanitary ball valves. But the advantages are limited because although the sealing surface of plug valves is far bigger than that of ball valves and the sealing effect is great, it also causes disadvantages like too much torque and inflexibility. The caliber of regular positive plug structure can’t be made too big due to the influence of the weight of the plug itself.
If you want to use large-size sanitary valves then you must use inverted plug structure, that is, the plug head faces down, which, inevitably, would reduce the sealing effect under the influence of gravity. So we can only seal using grease injection. The lubricant grease injected causes this kind of valve to be only used in the storage and transportation of natural gas and petroleum because lubricant grease can contaminate the medium. Although ball valves theoretically have a worse sealing effect, they can have very large caliber. Furthermore, with the improvement in processing precision and sealing materials, the sealing effect of ball valves can already meet the requirement of real-life applications very well. And it has a wider range of applications.
When used for regulating, the two are similar. Proper holes can be pierced into the rotating body of them to regulate.
Thus, usually plug valves are used on occasions where there’s a high requirement for sealing. But they have smaller calibers. Ball valves can be used on more and wider industrial occasions.