Mechanical seals are based on different operating environments, and the sealing surface materials are different. Good o-ring sealing surface materials can play an outstanding role in promoting mechanical seals. What are the raw materials for mechanical seal auxiliary O-rings?
 
1. Nitrile rubber NBR auxiliary mechanical seal O-ring: a synthetic rubber made by copolymerization of butadiene and acrylonitrile, with outstanding oil resistance, abrasion resistance, aging resistance and air tightness, but ozone resistance , Electrical insulation and cold resistance are relatively poor. (It has excellent corrosion resistance to mineral oil, animal and vegetable fats, and aliphatic hydrocarbons. It is widely used in equipment that touches gasoline and other oils. It is resistant to alkali and non-oxidizing dilute acid corrosion, and is not resistant to oxidizing acid {nitric acid, chromic acid} , Aromatic hydrocarbons, fats, ketones, ethers, halogenated hydrocarbons, so it is rarely used as a raw material for auxiliary sealing "O" rings of mechanical seals).
Applicable temperature: -40℃~120℃. Powder nitrile rubber (PNBR): a new product developed for different purposes.

2. EPDM regarding mechanical seals: it is a terpolymer of ethylene, propylene and non-conjugated diene (mechanical seal "O" ring simply does not need this raw material)

3. Fluorine rubber (FPM2602, F26) about mechanical seals: it has high temperature resistance, oil resistance, strong acid resistance, strong alkali resistance and strong corrosive media (common materials for mechanical seal "O" ring)
Applicable temperature: -7℃~175℃
 
4. Butyl rubber HR: mechanical seal "O" ring simply does not need this material
Common materials for mechanical seal "O" ring: fluoro rubber (FKM), perfluoro rubber (FFKM), nitrile rubber (NBR), double-layer PTFE-coated fluororubber, double-layer PTFE-coated ethylene propylene rubber, flexible graphite
Note: PTFE: polytetrafluoroethylene, good heat resistance, oil resistance and corrosion resistance
Applicable temperature: -150℃~250℃