Magic Skills To Extend The Service Life Of Mechanical Seal

Mechanical seal is an important part of the centrifugal pump.Do you know how to maintanance of it?Today let us talk about it together!


Mechanical seal of centrifugal pump is a device to prevent fluid leakage, which is composed of at least one pair of end faces perpendicular to the rotation axis under the action of fluid pressure, the elastic force (or magnetic force) of compensation mechanism and the cooperation of auxiliary seal to keep sticking and relative sliding.

Mechanical seal structure of centrifugal pump(see Figure 1 for typical structure principle) mainly consists of static ring (static ring)

1. Rotating ring

2. Elastic element

3. Spring seat

4. Set screw

5. Rotating ring auxiliary seal ring

6. Stationary ring auxiliary seal ring

mechanical seal of centrifugal pump

The anti rotation pin 7 is fixed on the gland 9 to prevent the rotation of the stationary ring.

Mechanical seal of centrifugal pump has the advantages of reliable sealing performance, small leakage, long service life, less power loss and wide application range. It is widely used in various technical fields, especially in the working conditions of high speed, high pressure difference and expensive, toxic and highly corrosive process media. At the same time, mechanical seal is one of the weakest links of the equipment.

In order to prolong its service life, in addition to choosing the right friction pair material and the right end face specific pressure, the correct installation and maintenance can also play an important role.

In this paper, through the practice of daily maintenance, the main causes of mechanical seal failure and leakage are analyzed, and the methods of how to extend the service life of mechanical seal of centrifugal pumpare summarized.

Mechanical seal of centrifugal pump has the advantages of reliable sealing performance, small leakage, long service life, less power loss and wide application range. It is widely used in various technical fields, especially in the working conditions of high speed, high pressure difference and expensive, toxic and highly corrosive process media. At the same time, mechanical seal is one of the weakest links of the equipment.

In order to prolong its service life, in addition to choosing the right friction pair material and the right end face specific pressure, the correct installation and maintenance can also play an important role.

In this paper, through the practice of daily maintenance, the main causes of mechanical seal failure and leakage are analyzed, and the methods of how to extend the service life of mechanical seal are summarized.

Mechanical seal of centrifugal pump leakage caused by the wear of the end face of the dynamic and static ring


No matter which type of mechanical seal of centrifugal pump, the main feature is that the sealing surface is perpendicular to the rotating axis, that is to say, the axial seal which is easy to leak is changed into the end seal which is not easy to leak. Therefore, the main form of mechanical seal failure of centrifugal pump is the wear failure between static and dynamic rings. The end friction pairs of the dynamic and static rings are mainly compressed by the spring thrust to prevent leakage. The tighter the dynamic and static rings are, the less likely they are to leak, but the friction between them also increases. The mirrors at the contact end of the dynamic and static rings will wear rapidly under the action of large friction, and finally fail to leak

mechanical seal of centrifugal pumps


Two point two

Mechanical seal leakage due to unstable process conditions and poor installation


The vibration caused by unstable process conditions and poor installation, and the instantaneous disconnection of equipment evacuation and vaporization will lead to the damage of the liquid film between the dynamic and static rings of the mechanical seal of centrifugal pump, which will make the mechanical seal run "dry" under the condition of no lubrication. The temperature of the seal ring will rise rapidly, some of which will burn directly, some of which will be cooled sharply when the centrifugal pump returns to normal working state, forming thermal shock and fragmentation. The poor flushing fluid and conditions will also cause thermal shock, which will lead to radial cracks in the seal ring and increase the wear failure of the dynamic and static rings. At the same time, when the temperature of graphite ring exceeds the service temperature, the crystal will precipitate on the surface of graphite ring, and carbonization will occur near the friction pair with higher temperature, and the particles will enter into the friction pair to make the dynamic and static ring wear out rapidly

mechanical seal of pump