Metal Bellows Seals Friction Resistance

Metal Bellows Seals Friction resistance

Introduction of metal bellows mechanical seal

First, what characteristics of bellows mechanical seal

The compensating mechanism is a bellows, one of which is made of a seal ring (movable ring or static ring) and a bellows, and there is no auxiliary seal between the non-balanced mechanical seals, thus reducing a leak point; while the mechanical seal reduces the compensation mechanism Of the friction resistance to improve the followability; for the welding metal bellows sealing the use of temperature is not subject to auxiliary sealing ring restrictions; for the tetrafluoroethylene bellows seal can be used in corrosive media. The drawback of the bellows mechanical seal is that the corrugated tube has a small elasticity and requires a secondary spring.

Second, the bellows mechanical seal which several kinds

Bellows mechanical seal application is very wide, from the imported mechanical seal low temperature to high temperature, from the neutral medium to corrosive media, from low to high speed, from the general to the harsh working conditions can be used.

All of these can change the elasticity of the bellows by changing the geometry of the bellows (such as inner and outer diameter, wave plate thickness and wave number, etc.) and material elastic modulus.

According to the corrosive properties of the media, use different bellows materials.

For example, the working pressure and temperature are not high neutral medium (oil and water, etc.), the choice of rubber made of simple bellows mechanical seal; in corrosive media (acid or alkali, etc.), the use of PTFE made of ripples Tube mechanical seal; high temperature and high speed, can be used to weld metal bellows mechanical seal.

Third, the metal bellows mechanical seal common faults

1) high temperature corrugated pipe failure, high pressure (such as the hot water pump) bellows rupture.

2 In the trough between the wave plate is prone to coking and carbon deposition phenomenon, so that the bellows is not flexible and can not compensate, it can not be used for coking, carbon deposition and crystallization of the pump.

3) on the external mechanical seal, the pressure in the sealed chamber more than 0.2mpa, the sealing surface can be pushed open. This is because the bellows is less elastic and can not withstand higher media pressure. Therefore, the pressure can not be used when the outer bellows mechanical seal.