Failure Analysis of Mechanical Seals of Slurry Pump


Published:

Dec 24,2023

Slurry pump downtime is mainly caused by the failure of the mechanical seal. Most of the manifestations of failures are leaks.

Failure Analysis of Mechanical Seals of Slurry Pump

Slurry pump downtime is mainly caused by the failure of the mechanical seal. Most of the manifestations of the failure are leaks, and the causes of leaks are as follows:

1. The main reasons for the leakage of the sealing surface of the dynamic and static ring are: the flatness and roughness of the end face do not meet the requirements, or the surface is scratched; There is particulate matter between the end faces, which causes the two end faces to not operate in the same way; The installation is not in place, and the way is not correct.

2. The main reasons for the leakage of the compensation ring sealing ring are: deformation of the gland and uneven preload; Incorrect installation; The quality of the sealing ring does not meet the standard; The seal is not selected correctly.

The actual use effect of the slurry pump shows that the part with many faults of the sealing element is the end face of the dynamic and static ring, and the sealing of the slurry pump machine and the cracking of the end face of the static ring are common fault phenomena, and the main reasons are:

1. The gap between the sealing surface is too large during installation, and the flushing liquid does not have time to take away the heat generated by the friction pair; Flushing fluid leaks through the gap between the seal faces, causing the end face to overheat and damage.

2. The liquid medium vaporizes and expands, so that the two end faces are separated by the vaporization expansion force, and when the two sealing surfaces are forcefully bonded, the lubricating film is destroyed and the end face surface is overheated.

3. The lubrication of the liquid medium is poor, coupled with the overload of the operating pressure, and the tracking and rotation of the two sealing surfaces are not synchronized. For example, the speed of the high-speed pump is 20445r/min, the center diameter of the sealing surface is 7cm, and the linear speed of the pump is as high as 75 m/s after operation.

4. The sealing flushing liquid orifice plate or filter screen is blocked, resulting in insufficient water volume and machine seal failure.

Keyword:

SLURRY PUMP