Development And Application of Mechanical Seals in Industry

Rubber is the most commonly used sealing material. In addition to rubber, other suitable sealing materials include graphite, polytetrafluoroethylene and various sealants.

Currently, various new mechanical seal technologies using new materials and processes are making rapid progress. There are the following new mechanical seal technologies. Sealing surface groove sealing technology In recent years, various flow grooves have been opened on the sealing end face of mechanical seals to produce hydrostatic and dynamic pressure effects, and it is still being updated.

Zero leakage sealing technology In the past, it was always believed that contact and non-contact mechanical seals could not achieve zero leakage (or no leakage). Israel uses slotted sealing technology to propose a new concept of zero-leakage non-contact mechanical end face seals, which has been used in lubricating oil pumps in nuclear power plants. Dry running gas sealing technology This type of seal uses slotted sealing technology for gas sealing. The upstream pumping sealing technology uses flow grooves on the sealing surface to pump a small amount of leaking fluid from the downstream back to the upstream.

The structural characteristics of the above types of seals are:

A shallow groove is used, and the film thickness and the depth of the flow groove are both in the micron level, and a lubricating groove, radial sealing dam and circumferential sealing weir are used to form the sealing and load-bearing part. It can also be said that the grooved seal is a combination of a flat seal and a grooved bearing.

Its advantages are small leakage (or even no leakage), large film thickness, elimination of contact friction, and low power consumption and heat generation. Thermal hydrodynamic sealing technology uses various shapes of deep sealing surface flow grooves to cause local thermal deformation to produce a hydrodynamic wedge effect. This kind of seal with hydrodynamic pressure bearing capacity is called a thermohydrodynamic wedge seal.

Bellows sealing technology can be divided into formed metal bellows and welded metal bellows mechanical sealing technology.

Multi-end sealing technology is divided into double sealing, intermediate ring sealing and multi-seal technology. In addition, there are parallel surface sealing technology, monitoring sealing technology, combined sealing technology, etc.