Causes of internal and external leakage of electric valves

The operating force distance of the electric valve is larger than that of ordinary valves. The switching speed of the electric valve can be adjusted. It has a simple structure and is easy to maintain. It can be used to control the flow of various types of fluids such as air, water, steam, various corrosive media, mud, oil, liquid metal and radioactive media. During the operation of traditional pneumatic valves, due to the buffering characteristics of the gas itself, they are not easily damaged by getting stuck, but they must have a gas source, and their control system is more complicated than that of electric valves.

In the daily use of electric valves, various faults are often encountered. Leakage of electric valves is one of the more common faults, and leakage of electric valves generally includes internal leakage and external leakage! So, what is the difference between the two?

Internal leakage of an electric valve generally refers to the situation where the medium still flows out, leaks or drips from the flow path outlet of the electric valve after the electric valve is completely closed. In layman's terms, it means that the closure is not tight and the sealing is not good! The cause of this failure is usually due to the erosion and wear of the medium, or the inclusion of impurities. Even if the electric valve screw (valve stem) is tightened in place, there is still a gap between the valve core and the valve body, and the medium can still flow through.

Leakage of an electric valve generally refers to the leakage of media from the external sealing component of the electric valve packing after the electric valve is completely closed or opened. That is, the tight seal between the electric valve and the connecting flange or connecting thread causes the medium to flow out of the connecting sealing surface, or the medium leaks due to the loose seal between the valve stem and the gland (that is, the gland that presses the packing on the valve stem), or the external leakage caused by trachoma on the valve body blank, and the external leakage caused by the wear of the valve body due to media erosion.