Oil Seals
Viton Oil Seals (FKM Oil Seals)
High-temperature rotary shaft seals in FKM (Viton®) fluoroelastomer — for applications where standard NBR oil seals cannot withstand the operating temperature, fluid chemistry, or both.
TC-type rotary shaft oil seals.
Overview
When to specify Viton over NBR
Standard oil seals use NBR (Nitrile) lip material, which handles mineral oils and greases well up to approximately +120 °C. Beyond that temperature — or in contact with synthetic lubricants, fuels, or aggressive chemicals — the NBR lip hardens, cracks, and loses sealing contact. FKM (commercially known as Viton®) extends the operating window to +200 °C continuous duty and resists a far broader range of fluids.
- Temperature: −20 °C to +200 °C continuous (short-term peaks to +230 °C)
- Chemical resistance: Mineral and synthetic oils, fuels, hydraulic fluids, solvents, weak acids, aromatics
- Shaft speed: Same as standard oil seals — up to 15 m/s peripheral speed depending on diameter
- Available types: TC, TB, SC, SB — all standard configurations, direct dimensional replacement for NBR versions
Applications
Typical Applications
Engine & Transmission
Crankshaft seals, camshaft seals, valve stem seals, and transmission output shaft seals exposed to high underhood temperatures and synthetic oils.
High-Temp Gearboxes
Gearboxes running synthetic PAG or PAO lubricants at elevated temperatures — steel mills, glass plants, ceramic kilns.
Pumps & Mixers
Process pumps handling hot oils, solvents, or mildly corrosive fluids where NBR would swell or dissolve.
Comparison
FKM vs NBR Oil Seals
| Property | NBR Oil Seal | FKM (Viton) Oil Seal |
|---|---|---|
| Temperature range | −40 °C to +120 °C | −20 °C to +200 °C |
| Mineral oil resistance | Excellent | Excellent |
| Synthetic oil resistance | Limited (PAG/ester attack) | Excellent |
| Fuel resistance | Good (limited aromatics) | Excellent |
| Ozone / UV resistance | Poor | Excellent |
| Cost | 1× | 3–5× |
| Low-temperature flexibility | Better (−40 °C) | Limited (−20 °C standard) |
Note: For applications requiring both low-temperature flexibility and chemical resistance, consider Fluorosilicone (FVMQ) lip material.
Sizes
Available Sizes
Viton oil seals are available in the same shaft × bore × width combinations as our standard NBR range — from 6 mm to 500 mm shaft diameter. All sizes are manufactured to order with 2–3 week lead time for standard dimensions.