When used for cutting off, the plug valve has a slightly better adjustment ability than the ball valve, but the advantages are limited. Although the sealing surface of the plug valve is much larger than that of the ball valve, the sealing effect is good, so the torque is too large and the action is not flexible enough. Due to the influence of the weight of the cock itself, it is difficult for the conventional positive cock structure to have a large diameter.
In practical applications, if a large-sized valve is to be used, the inverted cock structure must be used, that is, the large end of the cock is facing down, so that the sealing effect will inevitably be reduced under the action of gravity, so it has to be sealed by means of grease injection. The injected grease causes this This kind of valve can only be used for the storage and transportation of natural gas and oil, and cannot be used in other industries, because the grease will contaminate the medium. Although the sealing effect of the ball valve is slightly worse in theory, it can be made into a large diameter, and with the improvement of processing accuracy and sealing material, the sealing effect of the ball valve can already well meet the practical application requirements, and the application range is wider.
When used for adjustment, there is little difference between the two, and appropriate holes can be made on the rotating body for adjustment.
Therefore, the general plug valve is used in occasions with high sealing requirements, but the diameter is generally small, while the ball valve can be used in more and wider industrial occasions.

Therefore, we have to choose the valve according to the specific working situation.