Pump Mechanical seal Many kinds of different models, but there are five main leak:

Between the sleeve and the shaft seal;

The sealing ring and sleeve;

Dynamic and static seal ring;

The static ring and static ring sealing zama;

The sealing end cover and the seal between the pump body.

1 static test installation leakage

Engineering mechanical seal Good installation and commissioning generally try to be quiet to observe the leakage. Such as leakage of smaller, more dynamic or static ring ring ring problems; leakage is large, then the dynamic and static friction between the ring problem. In the preliminary observation of leakage, the leakage judgment based on the part of, and then manually turning observation, if leakage without significant changes in the static and dynamic seal ring problems; such as the disk when there are significant changes in leakage can be concluded that the dynamic, static friction ring problems; such as leakage along the axial direction is injection. Dynamic ring seal ring problems are medium to leak around the jet or water leaked from the cooling hole, mostly static seal ring failure. In addition, the leakage channels can also exist, but generally the difference between primary and secondary, as long as careful observation, familiar with the structure, can correct judgment.

The leakage occurred in 2 when commissioning. Pump with mechanical seal after static test, the operation of high-speed centrifugal force generated by the rotation, will inhibit the leakage of media. Therefore, when the mechanical seal leakage test run in the exclusion of shaft seal and cover, basically are due to dynamic and static friction ring caused by the destruction.

Causes of friction seal failure are:

In the operation, because of time, cavitation, such as hold pressure anomaly, the axial force caused by the larger, so that dynamic and static ring contact surface separation;

When the installation of mechanical seals excessive compression, resulting in friction and serious wear abrasion faces;

Dynamic tight ring seals, spring can not adjust the dynamic variable amount of axial ring;

Static seal ring too loose, when the dynamic axial floating ring, static ring from static ring seat;

Working media are granular materials, into the functioning of friction, dynamic testing, static seal face;

Design and selection is not correct, the low pressure end seal or sealing material such as shrinkage of the larger. This phenomenon often appears in the test run, sometimes can adjust the static ring seat to be eliminated, but most need to disassemble, replace the seal.

The two seal failure caused by the loss of lubricant:

Due to the existence of seal load, start the pump and dry friction occurs in the absence of liquid seal cavity;

The medium below the saturated vapor pressure, the occurrence of flash film face, loss of lubrication;

Such as the media for volatile products, in the mechanical seal cooling system scaling and blocking, due to friction and rotating components generate heat to mix the liquid saturated steam medium pressure rise, also caused the medium pressure is lower than the saturated vapor pressure of the situation.

Due to corrosion caused by mechanical seal failure: Sealing pitting, and even penetration.

As a result of tungsten carbide and stainless steel seat ring welding, the use of stainless steel seat easily intergranular corrosion.