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The Principle And Advantages Of Outer Packing Bellows Seal Are Introduced.
- Aug 17, 2018 -

The outer packing corrugated pipe seal is a kind of mechanical end face seal, the mechanical end face seal is a kind of axial end face seal, short for mechanical seal, also called end face seal, is a commonly used rotary shaft seal.Compared with other types of sealing (such as gland soft packing seal), it has a series of advantages such as low leakage, low friction and wear, long service life, reliable operation and no need to maintain pump mechanical seal at ordinary times.Therefore, it has been widely used in modern industrial production, especially in machine pump equipment. More than 85% of machine pumps use mechanical end face seal in major occasions.In addition, mechanical end face seal has achieved good application results under many high pressure, high temperature, high speed, inflammable, explosive and corrosive media.

The sealing surface of mechanical seal is made of hard alloy or ceramic, which is the same as other flowing parts of the pump. The mechanical seal of autoclave has corrosion resistance.Its function is to prevent the air from being drawn into the pump and the liquid from flowing out too much along the axis.Mechanical seal is divided into internal seal and external seal.

External sealing means that mechanical sealing device is outside the sealing chamber, when the medium is highly corrosive, and does not want to think about using pressure two layers of sealing, only consider using external mechanical seal.

As for the mechanical seal used in rolling equipment, it will be impossible to use if there is too much leakage. It is necessary to repair or replace it.Therefore, it is necessary to take the long period of smooth operation of equipment as the primary indicator to select mechanical seal.Generally speaking, welding metal corrugated pipe mechanical seal, compared with other kinds of mechanical seal functions in the application of a lot of fastness, the main elements are:

1. The mechanical seal face of corrugated pipe is under relatively uniform stress;

2. The mechanical seal of corrugated pipe has a good following property, which can compensate to a certain extent for the end face gap (usually less than 1) caused by the deflection of the rotating shaft, equipment oscillation, coaxial error of dynamic ring and axle sleeve and other factors, so as to reduce the leakage of mechanical seal.

3. Compared with mechanical seal of large spring type, mechanical seal of corrugated pipe is less affected by surface corrosion of axle sleeve.

4. The mechanical seal ring of the bellows is bolted to the mechanical seal gland.However, most of the static rings of mechanical seal of spring type are sealed by excessive cooperation between o-ring and mechanical seal gland, as well as the effect of fluid pressure and spring, which will be affected by the cooperation scale and corrosion degree of gland seal cover, and the sealing effect is poor.

However, the cost of mechanical seal of welded metal corrugated pipe is relatively high, but in terms of equipment working cycle per unit cost, it is much cheaper for most equipment to use mechanical seal of welded corrugated pipe.Especially like DBM series produced by dandong clonal group, the moving ring and shaft sleeve are bolted and tightened.