1. Leakage during installation static test
(1): If the leakage is small, most of the problems are the dynamic ring or static ring seal.
(2): When the leakage is large, it indicates that there is a problem between the dynamic and static ring friction pairs.
(3): On the basis of preliminary observation of the leakage amount and judgment of the leakage position, and then manual turning to observe if there is no significant change in the leakage amount, there are problems with the static and dynamic ring seals; there are problems with the friction pairs of the dynamic and static rings; Ring problems, static ring seal failure and other problems. In addition, leakage channels can also coexist.
2. Leaks during commissioning
The centrifugal force generated by the high-speed rotation of the mechanical seal for the centrifugal pump after the static test will suppress the leakage of the medium.
Therefore, the failure to seal the seal between the shaft and the end cover is basically caused by the damage of the friction pairs of the dynamic and static rings.
Most need to be disassembled and replaced with seals.
3. Sudden leakage during normal operation
Most of the sudden leakage of centrifugal pumps in operation are caused by large changes in operating conditions or improper operation and maintenance.
Evacuation, cavitation or prolonged squeezing, leading to seal damage;
The actual output of the pump is too small, and a large amount of medium is circulated in the pump, and heat is accumulated. Causes gasification of the medium, resulting in seal failure;
For long-term outages, there is no manual cranking when restarting, and the friction surface will damage the sealing surface due to adhesion
Corrosive, polymerizable and cementitious substances increase in the medium;
A sudden change in ambient temperature.
