What Is The Difference Between Internal Leakage And External Leakage Of Electric Brass Ball Valves?

In the daily use of electric brass valves, we often encounter various failures. The leakage of electric valves is a common one of many failures, and the leakage of electric valves generally has two cases of internal leakage and external leakage ! So, what is the difference between the two?

The internal leakage of the electric valve generally refers to the situation that after the electric valve is completely closed, there are still media outflow, leakage or drip from the flow path outlet of the electric valve. ! The cause of this failure is usually due to erosion and wear of the medium, or contains impurities. Even if the screw (stem) of the electric valve is screwed in place, there is still a gap between the valve core and the valve body, and the medium can still flow through.

The external leakage of the electric valve generally refers to the leakage of the medium of the external sealing part of the electric valve packing after the electric valve is completely closed or opened. That is, between the electric valve and the connection flange or the connection thread, the seal is not strict, causing the medium to flow out of the connection sealing surface, or the medium between the valve stem and the gland (that is, the gland of the pressure packing on the valve stem). Leakage, or external leakage caused by trachoma on the valve body blank, and external leakage caused by valve body wear due to media erosion.

The main factors that affect the dead zone of the electric valve: friction, movement, valve shaft torsion, the dead zone of the amplifier. The sensitivity of various control valves to friction is different. For example, rotary valves are very sensitive to the friction caused by high seat load, so pay attention to this when using them. But for some types of seals, a high seat load is necessary in order to obtain the closing level. In this way, the design of this valve is very poor, and it is easy to cause a large dead zone. This has obvious effects on the process deviation, and it is simply decisive.