When used for cutting off, the plug valve has slightly better adjustment ability than the ball valve, but the advantage is limited. Although the sealing surface of the plug valve is much larger than that of the ball valve, the sealing effect is good, but the torque is also large, and the action is not flexible enough. The conventional positive plug structure due to the plug Due to the influence of its own weight, it is difficult to make the caliber large.
In practical applications, if large-size valves are to be used, an inverted cock structure must be used, that is, the big end of the cock is facing downward. In this way, the sealing effect will inevitably be reduced under the action of gravity, so the sealing method must be sealed by grease injection. The injected grease will cause this This kind of valve can only be used for the storage and transportation of natural gas and oil, but cannot be used in other industries because grease will contaminate the medium. Although the sealing effect of ball valves is slightly worse in theory, it can be made into large diameters. With the improvement of processing accuracy and sealing materials, the sealing effect of ball valves can well meet the requirements of practical applications, and its application range is wider.
When used for adjustment, there is not much difference between the two. Appropriate holes can be made on the rotating body for adjustment.
Therefore, plug valves are generally used in situations with higher sealing requirements, but generally have smaller diameters; while ball valves can be used in more and wider industrial situations.