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The Advantages And Disadvantages Of Mechanical Seals
- Oct 02, 2018 -

mechanical seals advantages

(1) The structure is reliable, and the leakage amount can be limited to very small, as long as the surface roughness and straightness of the main sealing surface can meet the requirements, as long as the material wear resistance is good, the mechanical seal can achieve a small amount of leakage, and even the naked eye can not see. leakage.

(2) Long life. In the mechanical seal, the main wear part is the end face of the seal friction pair, because the wear amount of the seal end face is not large under normal working conditions, generally can be used continuously for 1 to 2 years, and also useful for 5 to 10 years in special occasions.

(3) No adjustment is required during operation. Since the mechanical seal is attached to the friction pair by the spring force and the fluid pressure, the contact is automatically maintained during operation, and the assembly does not need to be adjusted like ordinary soft filler.

(4) It has vibration resistance. The maximum amplitude does not exceed 0.05mm at a speed of 3000r/min. The PV value is continuously increased.

(5) The power loss is small. The packing seal is acted upon by the packing of the packing on the shaft or on the sleeve. The packing seal is directly rubbed with the shaft, and the tighter the friction of the packing pressure, the greater the power consumption and the greater the power consumption. The friction of the mechanical seal is in a semi-liquid friction state, the friction coefficient is very small, and the power loss of the mechanical seal is 10 to 50% of the packing seal.

(6) The bellows seal shaft or bushing is not subject to wear and is not sensitive to the wobble of the rotating shaft and the deflection of the shaft to the casing.

(7) A wide range of applications. When the medium is flammable, explosive, toxic and harmful, mechanical seals are used to ensure sealing. It is also suitable for equipment sealing of high temperature, low temperature, high pressure, vacuum various speeds and corrosive media.

2, disadvantages

(1) If the structure is more complex than the packing seal, the machining accuracy is high, and certain installation techniques are required, especially the dry gas seal installation requirements are higher. Moreover, the development of sealing technology is very fast, and the emergence of new technologies has brought new problems to our maintenance.

(2) The structure is complicated and inconvenient to assemble and disassemble. Compared with other seals, the mechanical end face seals a large number of parts, requiring precision and complicated structure. Especially in the assembly, it is difficult to remove the sealing ring from the shaft end during disassembly and assembly, and the machine part (coupling) must be completely removed. Some improvements have been made to this problem, such as split and cartridge mechanical seals that are easy to assemble and disassemble and that guarantee assembly quality.