Troubles And Measures Of Air-film Mechanical Seals

It is mainly divided into two parts to briefly introduce the failure problems and 

measures of the air film mechanical seal. One part is about the problem of the 

mechanical seal not being installed and the seal is running at low speed and no 

pressure, and the other part is about the sealing end face. Fractures, replacement 

of seals and repairs.

1. The problem of the end face fracture of the air film mechanical seal:

During the 

operation of the gas film mechanical seal for the kettle, although the possibility 

of cracking on the end face of the seal ring is very small, the possibility of this 

situation caused by the abnormal operation of the seal ring cannot be completely 

ruled out. If the sealing ring breaks on the process medium side, the pressure in 

the kettle will increase significantly. Therefore, take this into account when 

designing the gas-membrane mechanical seal for the kettle and the city's facilities.

2. How to replace or repair the air-membrane mechanical seal:

Most of the air-membrane mechanical seals used in the kettle are cartridge-type devices, which can 

be easily replaced by trained assemblers. Due to the particularity of the sealing ring end face and the groove design, it is impossible to reprocess the rotary seat of the sealing ring end face. Therefore, the user should have spare parts for replacing the sealing ring or a set of sealing devices.

3. Improperly installed air film mechanical seal:

When the gas-film mechanical seal 

for the kettle with one-way grooves can only move in one direction of rotation. When 

designing and installing, attention should be paid to the direction of rotation. If

the rotation direction of the gas film mechanical seal ring used in the kettle is 

opposite to that of the main shaft, it is allowed in a short period of time. If this 

is done for a long time, it will lead to dry running of the seal contact, which will

worsen the wear of the end face. However, under low-speed operation, the probability 

of failure due to the fact that the sealing surface is broken is not very high.

4. The sealing ring runs without pressure at low speed:

Low-speed running gas film mechanical seals that do not supply blocking gas, where there will be local contact. This can also happen if the gas supply is insufficient and cannot be gas pressured. 

A seal with a combination of hard and soft sealing materials operates similarly to a 

dry-running seal, with accompanying wear. If a hard face sealing material is used, 

it is a matter of time to seal the face. Even so, the sealing end face does not 

easily break naturally.