Some seals handle steam. Some handle oil. But only a fluoroelastomer seal can handle both—plus fuels, chemicals, and extreme heat—without breaking down.
A fluoroelastomer seal is a high-performance rubber component made from FKM (fluoroelastomer) designed to resist heat, oils, fuels, and chemicals in static or dynamic sealing applications.
In our production line, we rely on fluoroelastomer seals when regular rubbers like NBR or EPDM can’t survive. Whether it’s a crankshaft, pump, or chemical valve—FKM seals keep it tight.
What is another name for fluoroelastomer?
If you’ve heard the name Viton®, you’ve already encountered fluoroelastomer—it’s just the branded version.
Fluoroelastomer is also known as FKM (ISO standard) or FPM (DIN standard), and Viton® is the most well-known trademarked brand of this material.
🧾 Naming Breakdown
| Name | Origin |
|---|---|
| FKM1 | ISO 1629 material code |
| FPM | German DIN/EN abbreviation |
| Viton®2 | Trademark by Chemours (DuPont) |
| Fluoroelastomer3 | Generic industry name |
In our catalogs, we use “FKM” when referring to the material generically. When a customer requires brand-specific sourcing for aerospace or OEM applications, we’ll source genuine Viton® upon request.
What is fluoroelastomer material?
Fluoroelastomer, also known as FKM (ISO) or FPM (DIN), is a synthetic rubber containing fluorine atoms, giving it superior resistance to heat, chemicals, and oil-based fluids.
It was first developed by DuPont (now Chemours) under the Viton® brand and remains the top choice for harsh sealing conditions.
✅ Key Properties of FKM Rubber
| Feature | Performance |
|---|---|
| Heat resistance4 | Up to 230°C (some grades to 300°C) |
| Oil/fuel resistance | Excellent |
| Chemical resistance5 | Very strong (solvents, acids, bases) |
| Compression set | Low (holds sealing shape well) |
| UV/ozone resistance6 | Excellent |
We use FKM when producing shaft seals, O-rings, and flange gaskets for oil and gas, chemical, and automotive industries. It’s the go-to for long-term durability under stress.
What does a fluoroelastomer seal do?
A fluoroelastomer seal works by compressing in a groove or housing to block fluids or gases. It stays flexible over time and resists breakdown even under aggressive chemical attack.
These seals are used to prevent leakage and contamination in high-temperature, chemically aggressive, and oil-exposed environments.
🛠️ Common Fluoroelastomer Seal Types
| Seal Type | Application |
|---|---|
| O-rings | Static sealing in pipes, pumps |
| Shaft seals | Rotary sealing in engines, gearboxes |
| Gaskets | Flange and housing sealing |
| Diaphragms | Valves, dosing systems |
| Lip seals | Dynamic contact on rotating shafts |
We mold FKM seals7 with spring-reinforced lips8 for rotating shafts in oil-rich compressors, as well as precision-cut FKM gaskets9 for flanged chemical valves.
Where are fluoroelastomer seals used?
Anywhere regular rubber fails due to oil, fuel, or heat, FKM comes in. It’s trusted in aerospace, automotive, chemical processing, and HVAC.
Fluoroelastomer seals are used in engines, pumps, fuel systems, compressors, and reactors—wherever aggressive media and high temperatures are present.
📍 Common Applications
| Industry | Use Case |
|---|---|
| Automotive | Crankshaft seals, injector O-rings10 |
| Chemical plants | Pump gaskets, tank seals11 |
| Aerospace | Fuel system seals, engine components12 |
| HVAC | Compressor shaft and valve seals |
| Oil & gas | Valve seats, casing gaskets |
In one HVAC project, we supplied FKM seals for refrigerant compressors exposed to synthetic oils and high pressure. They ran continuously for over 18 months without leakage.
How does FKM compare to other sealing materials?
Compared to NBR, EPDM, or silicone, fluoroelastomer outperforms in durability, chemical resistance, and temperature handling.
It’s more expensive—but for critical environments, it's often the only seal that survives.
🔍 Material Comparison Summary
| Feature | NBR | EPDM | Silicone | FKM (Fluoroelastomer) |
|---|---|---|---|---|
| Fuel/oil resistance13 | ❌ | ❌ | ❌ | ✅ |
| Chemical resistance | ⚠️ Moderate | ⚠️ Moderate | ✅ Good | ✅✅ Excellent |
| Heat resistance | ⚠️ Max 120°C | ✅ 150°C | ✅ 200–230°C | ✅✅ 230–300°C |
| Compression set | ⚠️ Fair | ✅ Good | ✅ Good | ✅✅ Excellent |
| Cost | $ | $ | $$ | $$$ |
We help customers evaluate both budget and performance. In high-stakes systems, the extra cost of FKM is usually worth avoiding failure.
Are there different grades of fluoroelastomer?
Yes. FKM comes in multiple types—each formulated for specific resistance needs like steam, amines, fuels, or acids.
Grades include Type A, B, F, and perfluorinated versions (like FEPM), each offering different chemical and thermal properties.
📌 Grade Guide
| Type | Resistance Focus | Example Application |
|---|---|---|
| Type A | General fuel and oil14 | Automotive oil seals |
| Type B | Improved chemicals15 | Chemical reactor O-rings |
| Type F | Bases and steam | High-temp CIP valves |
| FEPM | Amines, hot acid, aggressive16 | Aerospace fuel systems |
We can recommend specific FKM types for whatever chemical media or process conditions you’re working with.
Is fluoroelastomer expensive?
Yes—but for a reason. FKM isn’t cheap like EPDM or NBR, but its performance in extreme environments makes it cost-effective over time.
Fluoroelastomer is significantly more expensive than standard rubbers due to its complex chemistry, high-temperature processing, and premium resistance properties.
💰 Cost Comparison (Estimated)
| Material | Relative Cost | Value Justification |
|---|---|---|
| EPDM | $ | Good for water, poor in oil/fuel |
| NBR | $$ | Oil-resistant but not for high temps |
| Silicone | $$ | Great for heat, but weak in chemicals |
| FKM (Viton®) | $$$–$$$$ | Long life in oil, fuel, chemicals, and heat |
Many of our industrial clients switch to FKM after losing too many seals to swelling, cracking, or heat degradation. While the upfront price is higher, they save money in downtime and replacement costs.
In my experience: if your system runs hot, handles fuels, or cannot afford failure—FKM pays for itself.
Conclusion
A fluoroelastomer seal is the sealing solution for harsh conditions—built to endure fuel, oil, chemicals, and heat where other rubbers fail.
Need custom FKM seals for your toughest projects?
Contact Julong Rubber or Request a Quote for molded, extruded, or die-cut FKM seals.
Or connect with us now on WhatsApp:
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Explore this link to understand the applications and benefits of FKM material in various industries, enhancing your knowledge on its uses. ↩
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Discover the unique properties of Viton® that make it a preferred choice in aerospace and OEM applications, ensuring quality sourcing. ↩
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Learn about fluoroelastomers and their significance in the industry, providing insights into their versatility and performance. ↩
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Understanding the heat resistance of FKM materials is crucial for applications in high-temperature environments, ensuring reliability and safety. ↩
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Exploring FKM's chemical resistance can help you choose the right material for harsh environments, enhancing product longevity. ↩
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Learning about UV/ozone resistance in FKM can inform your decisions for outdoor applications, ensuring durability against environmental factors. ↩
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Explore this link to understand the advantages of FKM seals, especially in oil-rich environments, enhancing performance and durability. ↩
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Learn how spring-reinforced lips enhance the effectiveness of seals, ensuring better sealing in dynamic applications like compressors. ↩
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Discover the applications and benefits of precision-cut FKM gaskets in chemical valves, ensuring reliable sealing under various conditions. ↩
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Understanding these components is crucial for automotive maintenance and performance. Explore to enhance your knowledge! ↩
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Learn about the importance of these seals in ensuring safety and efficiency in chemical processes. A must-read for industry professionals! ↩
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Discover the critical role these components play in aerospace safety and performance. Essential information for aviation enthusiasts and professionals! ↩
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Understanding fuel/oil resistance is crucial for selecting the right elastomer for your application. Explore this link for detailed insights. ↩
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Explore this link to understand how General fuel and oil are crucial for automotive applications, ensuring optimal performance and longevity. ↩
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Discover the benefits of Improved chemicals in enhancing the durability and efficiency of chemical reactor O-rings, vital for safety and performance. ↩
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Learn about the challenges and solutions in using materials resistant to harsh environments, essential for aerospace fuel systems. ↩
