Mechanical seal, also known as mechanical seal, is a dynamic seal for rotating shaft. The mechanical seal has reliable performance, small leakage, long service life and low power consumption. It does not need regular maintenance, and can adapt to production process automation and high temperature, low temperature, high pressure, vacuum, high speed and various strong corrosive media. The sealing requirements of the medium containing solid particles and other harsh working conditions. Mechanical seal is a kind of shaft seal device which can prevent leakage by a pair or several pairs of end faces which are perpendicular to the shaft and keep connected under the action of fluid pressure and elastic force (or magnetic force) of compensation mechanism. The requirements of gear oil pump for mechanical seal, mechanical seal and soft packing seal are compared as follows:

Advantages: 1) the sealing is reliable, the sealing state is very stable in long-term operation, and the leakage is small, and the leakage is about 1% of that of soft packing seal

2) Long service life, in oil, water medium generally up to 1 ~ 2 years or longer. Working in chemical media for more than half a year

3) The friction power consumption is small, and the friction power is only 10% ~ 50% of the soft packing seal

4) The shaft or sleeve is basically free from friction damage

5) The maintenance cycle is long. After the end face is worn, it can be automatically compensated. In general, it does not need regular maintenance

6) It has good seismic resistance and is insensitive to vibration of rotating shaft and deflection of shaft to sealing chamber

7) Mechanical seal can be used in high temperature, low temperature, high pressure, vacuum, different rotation frequency, as well as various corrosive media and abrasive media.

Disadvantages:

1) It is more complex and requires high processing

2) Installation and replacement are troublesome, requiring workers to have a certain level of technology

3) It is difficult to deal with accidental accidents.

Preparation before high price sealing:

1) Check the type of mechanical seal. Whether the specifications meet the requirements of the design drawing, so whether the parts (especially the sealing surface and auxiliary sealing ring) are damaged. Deformation. Cracks and other phenomena, if there are defects, must be replaced or repaired

2) Check whether the matching dimension, roughness and parallelism of mechanical seal parts meet the design requirements

3) When using small spring mechanical seal, check whether the length and rigidity of small spring are the same

4) Check the movement of the main engine. Whether the swing amount and winding meet the technical requirements, whether the seal chamber meets the installation scale, whether the seal end cover is vertical to the shaft, and the general requirements are: the shaft displacement shall not be greater than ± 0. 5mm: the shaft swing (at the rotating ring seal ring) is not greater than 0. 06mm: the maximum winding of the shaft is not greater than 0. 05mm: the allowable deviation of the perpendicularity of the contact plane between the seal end cover and the gasket to the center line is 0. 03~0。 05mm

5) It should be kept clean, especially the sealing surface of rotating ring and stationary ring and the surface of auxiliary sealing ring should be free of impurities. Dust. It is not allowed to wipe the sealing surface with unclean non wiping.

6) It is not allowed to knock the sealing elements with tools. To prevent the seal from being damaged.

Technology Department