Mechanical seal auxiliary O type ring commonly used material

Mechanical seal according to the environment is not the same, the sealing surface of the material is not the same, the O-ring sealing surface data on the mechanical seal to the outstanding role of mechanical seal assisted O ring what material?
1, nitrile rubber NBR assisted mechanical seal O type ring: a synthetic rubber copolymerization of butadiene and acrylonitrile is prepared, with excellent oil resistance, abrasion resistance, aging resistance and air tightness, but ozone resistance, electrical insulation and cold resistance are relatively poor. (mineral oil, animal and vegetable oils, aliphatic hydrocarbons have excellent corrosion resistance, widely used in touch gasoline and other oil equipment, energy and non oxidizing dilute acid and alkali corrosion, no oxidation resistant acid nitric acid, chromic acid, {}, ester, ketone, aromatic ether, halogenated hydrocarbon corrosion, so rarely used for machinery seal seal assisted "O" ring material)
Applicable temperature: ~120 C -40 C. Powdered nitrile rubber (PNBR): new products meet different use development.
2, three yuan of ethylene propylene rubber mechanical seal: ethylene, propylene and non conjugated diene copolymer (three mechanical seal "O" ring almost don't have this material)
3, fluorine rubber (FPM2602, F26) on the mechanical seal: high temperature resistance, oil resistance, strong acid, strong alkali and strong corrosive medium (commonly used data of mechanical seal type "O" ring)
Applicable temperature: ~175 C -7 C
4, butyl rubber HR: mechanical seal "O" type ring simply do not have this raw material
Mechanical seal ring material commonly used "O" type: fluorine rubber (FKM), perfluorinated rubber (FFKM), nitrile rubber (NBR), double coated PTFE double coated PTFE fluorine rubber, ethylene propylene rubber, flexible graphite
Note: PTFE: PTFE, heat resistance, oil resistance, corrosion resistance is better
Applicable temperature: ~250 C -150 C