1. Leak when installing static test. Mechanical seal installation and commissioning, the general test to see the leakage. Such as leakage is small, mostly there is a problemin dynamic ring or static ring ; leakage is large, then there is a problem between moving and static ring.
2. Leak during test run. Mechanical seal After a static test, high-speed rotation during operation to produce centrifugal force, will inhibit the fluid leakage. Therefore, the test machine mechanical seal leakage, in the exclusion of the shaft and the end of the seal after the entry into force, are basically due to moving and static ring friction caused by damage. The factors that cause the failure of the friction seal are:
2.1 When operation, due to evacuation, cavitation, pressure and other abnormal phenomena, causing a larger axial force, so that dynamic and static ring contact surface separation;
2.2 Mechanical seal compression is too large, friction face serious wear and tear abrasion;
2.3 Dynamic ring seal is too tight, the spring can not adjust the dynamic ring axial volume;
2.4 Static ring ring too loose, when the dynamic ring floating, the static ring break away from the static ring seat;
2.5 Fluid particles into the friction material, scratches the static and dynamic ring sealing surface;
2.6 Design selection is wrong, sealing the end of the low pressure or sealing surface material cold shrinkage larger. The above phenomenon often occurs during operation, most of the need to replace the seal.
3.Normal operation suddenly leaked. Centrifugal pumps are suddenly leaked during operation minority due to wear or it has reached the service life, mostly due to large changes in operating conditions or improper operation caused.
3.1 Due to evacuation, cavitation or a long time to suppress pressure, resulting in sealing damage;
3.2 The actual output of the pump is too small, a large number of media inner circulation, heat accumulation, causing the media gasification, resulting in sealing failure;
3.3 Long outage, start without turning the car, the friction sticky pull bad seal surface;
3.4 frequent changes in operating conditions, sudden changes in ambient temperature or sudden power failure and so on. In short, in the maintenance must be meticulous observation, careful analysis, taking into account the many possibilities.
