The Use Range Of Shallow Groove And Deep Groove Of Mechanical Seal

Mechanical seals with shallow grooves and deep grooves have their own individual structural designs. Different structural designs have different application scope and characteristics of the grooves.

1. The scope of application of the shallow groove in the mechanical seal

When the mechanical seal is sealed with a shallow groove structure, the sealing effect is good, but if the fluid contains impurities or dirt, it may block the sealing groove, so that the existence of the liquid film cannot be successfully maintained, and the fluid dynamics will be lost. When the sealing function is over, the sealing end face damage and mechanical damage will soon occur,and at the same time, it may cause serious sealing leakage and reduce the service life of the sealing ring. At the same time, the shallow groove sealing ring also has high requirements on the installation accuracy, which directly affects the use effect of the seal. Research shows that the dynamic pressure effect of the shallow groove non-contact mechanical sealing ring is more stable at high speed.

Generally speaking, shallow groove mechanical seals may be preferred for dry gas seals in the following situations:

1. Zero escape of sealing medium is required;

2. The sealing medium heats up the friction;

3. Require process products;

4. The pump is easily evacuated and the seal runs dry;

5. The sealing auxiliary system is required to be simple and reliable;

6. Requires low sealing maintenance costs, etc.

When the shallow groove mechanical seal is used to seal the gas, the complicated auxiliary sealing system can be eliminated. The scope of application of the upstream pumping seal is roughly similar to that of the dry gas seal. Although its energy saving and consumption reduction effect is not as good as that of the dry gas seal, it has a wide range of applications, that is, it can be used to seal with zero leakage under some less severe conditions. There is no need for a buffer auxiliary system, and it can be used as a zero-escape seal with a buffer system under conditions that require strict control of the leakage of the sealing medium, but the pressure of the buffer is much lower than the pressure of the seal quality. , from the practical point of view, the upstream pumping seal should have a wider range of use.

2 The scope of application of mechanical seal deep groove

The deep groove structure of the mechanical seal can be successfully used to maintain the existence of the liquid film. The groove depth of the deep groove is in the order of millimeters, but the film thickness is in the micrometer level. At this time, the ratio of the groove depth to the film thickness is will be bigger. The deep groove of the deep groove non-contact mechanical seal makes the circumferential deformation of the end face into a wave shape, which generates a dynamic pressure increment and increases the static pressure bearing capacity. As a result, the dynamic pressure fluctuation of the seal is reduced, which is conducive to the stable operation of the seal. The rotational speed and installation accuracy have little effect on the sealing performance. The deep groove end face sealing ring structure can realize the non-contact operation of the end face, but the operating power is slightly lower than that of the shallow groove type. It is suitable for high pressure and high speed working environment. High parameter and high temperature and high pressure water seal or high speed liquid phase turbine pump seal.