Common materials for auxiliary O-rings of mechanical seals
Depending on the environment in which the mechanical seal is used, the material of the sealing surface is also different. What is the material of the sealing surface material of the O-ring on the mechanical seal that plays a prominent role in the auxiliary O-ring of the mechanical seal?
1. Nitrile rubber NBR auxiliary mechanical seal O-ring: a synthetic rubber made by copolymerization of butadiene and acrylonitrile, which has excellent oil resistance, abrasion resistance, aging resistance and air tightness, but ozone resistance, electricity Poor insulation and cold resistance. (Mineral oil, animal and vegetable oil, and aliphatic hydrocarbons have excellent corrosion resistance, and are widely used in gasoline and other oil equipment. They can corrode non-oxidizing dilute acids and alkalis, and are not resistant to oxidizing acids such as nitric acid, chromic acid, {}, esters, Corrosion of ketones, aromatic ethers, and halogenated hydrocarbons, so it is rarely used in mechanical seals (sealing auxiliary "O" ring materials)
Applicable temperature: ~120℃-40℃. Powdered nitrile rubber (PNBR): a new product developed to meet different purposes.
2. EPDM mechanical seal: ethylene, propylene and non-conjugated diene copolymer (the "O" ring of ternary mechanical seal has almost no such material)
3. Fluorine rubber on the mechanical seal (FPM2602, F26): high temperature resistance, oil resistance, strong acid resistance, strong alkali resistance and strong corrosive medium (common data for mechanical seal "O" rings)
Applicable temperature: ~175℃-7℃
4. Butyl rubber HR: mechanical seal "O" ring does not have this kind of raw material at all
Mechanical seal ring materials commonly used "O" type: fluorine rubber (FKM), perfluororubber (FFKM), nitrile rubber (NBR), double-coated PTFE double-coated PTFE fluororubber, ethylene-propylene rubber, flexible graphite
Note: PTFE: polytetrafluoroethylene, good heat resistance, oil resistance and corrosion resistance
Applicable temperature: ~250℃-150℃