• Follow us
Home > Knowledge > Content
How to judge whether the valve is internal or external leakage
May 23, 2018

In the daily use of electric valves, often encountered a variety of failures, electric valve leakage is a common one of many failures, and the leakage of electric valves generally have two kinds of leakage and leakage. So, what's the difference between the two?

The internal leakage of electric valve, generally refers to when the electric valve is completely closed, there is still medium from the circulation of electric valve outlet, leakage or drip leakage and other conditions, the popular point is not strict, seal is not good! The cause of the fault is usually caused by erosion or wear of the medium or impurities. Even if the electric valve screw (stem) is screwed in place, there is still a gap between the valve core and the valve body, and the medium can also flow through.

The leakage of electric valves usually refers to the leakage of media when the electric valves are completely closed or opened. That is, between the electric valve and the connecting flange or connecting thread, the seal is not strictly sealed, which causes the medium to flow out of the connection seal, or the leakage of the medium caused by the tight seal between the stem and the Gran (the gland of the stem on the stem of the valve stem), or the leakage caused by the sand eye on the body blank, and the body mill due to the erosion of the medium. Loss of leakage.

The main factors that affect the dead zone of electric valve are friction, wandering, torsion of valve shaft and dead zone of amplifier. Various control valves are sensitive to friction, for example, the rotary valve is very sensitive to the friction caused by the high seat load, so it is noticed in use. But for some sealing types, high seat load is necessary to achieve a closed level. In this way, the design of the valve is very poor, and it is easy to cause a large dead zone, which is obvious to the deviation of the process.