Leakage of Mechanical Seals and Its Maintenance Countermeasures

What equipment are mechanical seals mostly used on? In general, mechanical seals are mostly used in centrifugal pumps, centrifuges, compressors and reactors. It has good sealing performance, low leakage, long service life, low energy consumption and does not require frequent maintenance. Mechanical seals are also very good in adaptability. Generally, they can adapt to various harsh environments such as automated production, high temperature and high pressure, and harsh requirements for sealing.

Common mechanical seals leaks are as follows:

1. Leakage caused by damage to the flatness of the mechanical seals surface

The damage to the sealing surface is mostly uneven scratches and facial cut marks. The cause may be deformation or damage of the seal box of the pump and the head of the agitator. Or the uneven tightening force of the bolts causes deformation of the sealing surface of the static ring, and finally leakage occurs. It is also possible that the shape of the sealing surface changes due to temperature changes and thermal expansion differences when the sliding parts are shrink-fitted. Sealing can also be damaged as a result, leading to leakage problems.

2. Leakage caused by damage to the lubricity of the mekanikal seal surface

The lubricity of the face seal is also very important. In addition to relying on the end face liquid film for sealing, it also relies on lubrication to complete normal operation. Once the end face liquid film is damaged, it will cause instant wear and roughness of the dry friction sealing surface, and even some hard materials will produce cracks and other serious phenomena. When the temperature of the sliding friction surface rises suddenly, if the heat accumulation cannot be removed immediately, the sealing liquid will evaporate and the lubricating film will disappear, which will lead to the occurrence of dry friction. Dry friction can easily damage the sealing surface and bury a lot of hidden dangers of leakage.

3. Leakage caused by mekanikal seal action damage

The moving ring and stationary ring of the mechanical seal are always rotating with the shaft, and they have been frequently and repeatedly repeating the same movement. This repetitive movement will not only change the seal face, but also increase the axial movement of the device, gradually reducing the accuracy of the mechanical seal. In this way, various parts of the device will be damaged or even deformed for a long time, thereby losing the follow-up ability and resulting in leakage of the seal.

What will affect the action of the mechanical seal? First of all, the accumulation of slurry will hinder the action of the spring, the movement of sliding parts will be out of control, and the surface of the sealing surface will be worn. These seriously affect the action of the mechanical seal. When the sliding sealing surface is worn, hardened and aged, the shaft and bushing will be damaged, and the spring seat will also wear and even bend.

4. Mechanical seal leakage caused by the superposition of multiple factors

Leaks sometimes occur due to a combination of factors. For example, a combination of factors such as dry friction, poor sliding, slip ring deformation, and flatness deformation can easily cause leakage. Many of these are caused by excessive fatigue, uneven pressure and liquid film damage. Therefore, the correct installation and maintaining the cleanliness of the mechanical seal are very important. Coupled with good cooling, this can better eliminate hidden dangers.