Rubber is the most commonly used sealing material. In addition to rubber, other suitable sealing materials include graphite, polytetrafluoroethylene, and various sealants.
Currently, new mechanical seal technologies utilizing new materials and processes are rapidly developing. The following new mechanical seal technologies are being developed: Grooved Sealing Technology: In recent years, various flow grooves have been created on the sealing face of mechanical seals to generate static and dynamic pressure effects, and this technology is still being continuously updated.
Zero-leakage Sealing Technology: It was previously believed that contacting and non-contacting mechanical seals could not achieve zero leakage (or no leakage). Israel has developed a new concept of zero-leakage, non-contacting mechanical face seals using grooved sealing technology, which has been used in lubricating oil pumps in nuclear power plants. Dry-running gas sealing technology applies grooved sealing technology to gas sealing. Upstream pumping sealing technology uses grooves on the sealing face to pump any leaking fluid downstream back upstream.
The structural features of the aforementioned seal types are:
They utilize shallow grooves, with film thickness and groove depth both in the micron range. Lubrication grooves, radial sealing dams, and circumferential sealing weirs form the sealing and load-bearing components. A slotted seal can be considered a combination of a flat seal and a slotted bearing.
The advantages include low leakage (or even no leakage), high film thickness, elimination of contact friction, and low power consumption and heat generation. Thermal hydrodynamic sealing technology utilizes various deep grooves on the sealing surface to create localized thermal deformation, generating a hydrodynamic wedge effect. This type of seal with hydrodynamic load-bearing capacity is called a thermal hydrodynamic wedge seal.
Bells sealing technology can be divided into formed metal bellows and welded metal bellows mechanical seals.
Multi-face sealing technology is categorized into dual seals, intermediate ring seals, and multi-seals. Other seal technologies include parallel face seals, monitoring seals, and combined seals.
