In the daily use of the valve, often encounter a variety of failures, the valve leakage is the most common one of many failures, and the leakage of the valve generally have two situations of internal leakage and leakage! So what's the difference between the two?
The inner leakage of the valve generally refers to the fact that when the valve is completely closed, there is still a situation in which the medium flows out from the flow path outlet of the valve, leaks or leaks, etc.. In terms of popular points, it is not closed, and the seal is not good! The cause of this fault is usually caused by the erosion of the medium or the presence of impurities. Even if the valve screw (stem) is screwed into place, the medium can flow because there is still a gap between the valve body and the valve body.
The external leakage of the valve generally refers to the leakage of the medium when the valve is completely closed or opened, and the external packing of the valve packing is used. That is, the leakage between the valve and the connecting flange or the connecting thread is caused by the loose seal, which leads to the medium flowing out of the connecting sealing surface, or the leakage of the medium caused by the poor seal between the stem and the Grand (ie, the pressure cover of the stem on the valve stem). Or external leakage caused by trachoma on the blank of the valve body, and external leakage caused by wear of the valve body due to media erosion.