Materials of Excellence

Crafting with the Best in the Business

At Julong Rubber, we prioritize using the finest materials to ensure the durability, efficiency, and performance of every product. Explore the various high-quality materials that form the foundation of our premium rubber components.

Fluorocarbon (FKM/Viton)

The Superior Defender Against Harsh Elements

Fluorocarbon rubbers, commercially known as FKM or by the brand name Viton, stand out in the rubber family due to their exceptional chemical resistance. Especially designed to resist degradation from exposure to a wide range of aggressive chemicals, these elastomers are also renowned for their high-temperature resilience. Moreover, their capability to withstand oxidation and retain their properties even in extreme conditions make them a popular choice in industries that operate in severe environments.

Fluorocarbon Rubber (FKM/Viton): Properties

Fluorocarbon rubber, commonly known as FKM or Viton, is one of the most advanced elastomers used in sealing solutions. With outstanding resistance to heat, chemicals, and oils, it is the go-to choice for demanding industrial environments. But is it worth the higher cost? Let’s explore its benefits, limitations, and how it compares to alternatives like EPDM.

Fluorocarbon rubber (FKM), also known by the trade name Viton®, is a high-performance synthetic rubber that offers exceptional resistance to heat, oils, fuels, and many chemicals. It is widely used in automotive, aerospace, and chemical industries for seals, O-rings, and gaskets.

What is Fluorocarbon Rubber?

Fluorocarbon rubber, abbreviated as FKM, is a class of synthetic rubber made from fluoroelastomers. It is primarily composed of vinylidene fluoride (VDF) and other fluorinated monomers. DuPont’s Viton® is the most recognized brand of FKM rubber.

FKM rubber is known for its exceptional resistance to high temperatures, oils, fuels, and aggressive chemicals, making it ideal for critical sealing applications in harsh environments.

Is Fluorocarbon Rubber the Same as Viton?

Yes, Viton® is a specific brand of fluorocarbon rubber (FKM) produced by DuPont (now Chemours). While Viton is a well-known trademark, FKM refers to the general class of fluorocarbon elastomers made by various manufacturers.

✅ Viton®: Brand name from DuPont/Chemours.
✅ FKM: International standard term (ISO/DIN).

In industry practice, “Viton” and “FKM” are often used interchangeably, although Viton has specific grades and quality controls set by Chemours.

What Are the Advantages and Disadvantages of Viton?

🏆 Advantages of Viton (FKM)

✅ Advantage	🔍 Description
🔥 High Temperature Resistance	Continuous use at temperatures up to 250°C, short-term up to 300°C.
🛢️ Excellent Chemical Resistance	Resists oils, fuels, solvents, and many aggressive chemicals.
☀️ Weather & Ozone Resistance	Highly resistant to aging, UV, and ozone exposure.
💪 High Compression Set Resistance	Maintains shape and sealing force under compression and high temperatures.
🧪 Low Gas Permeability	Excellent barrier for gases and vapors.

⚠️ Disadvantages of Viton (FKM)

❌ Disadvantage	🔍 Description
💰 High Cost	Significantly more expensive than general-purpose elastomers like EPDM or NBR.
❄️ Poor Low-Temperature Flexibility	Becomes stiff below -15°C to -25°C, depending on grade.
⚡ Limited Resistance to Amines and Ketones	Certain chemicals like ketones, amines, and some esters can degrade FKM.

What is the Difference Between FKM/Viton and EPDM?

🔍 Property	🏆 FKM (Viton)	🏆 EPDM
Temperature Range	-20°C to +250°C	-50°C to +150°C
Oil/Fuel Resistance	Excellent	Poor
Chemical Resistance	Excellent (hydrocarbons, solvents)	Good (water, steam, polar solvents)
Weather & Ozone Resistance	Excellent	Excellent
Cost	High	Low
Common Applications	Oil seals, fuel systems, aerospace	Water seals, roofing membranes, HVAC

Application of Fluorocarbon in Different Industries

Fluorocarbon elastomers are widely used in sectors demanding materials that maintain performance under extreme temperatures and chemical exposures. Below is an in-depth analysis of their specific applications.

🚗 Automotive Industry

The automotive sector relies heavily on FKM rubber for its superior resistance to fuels, oils, and high temperatures. FKM seals ensure long service life in engines, fuel systems, and transmissions.

✅ Applications: O-rings, shaft seals, fuel hose linings, gaskets, valve stem seals.
✅ Key Advantages:
- Resists fuels, oils, and hydraulic fluids
- Performs at high temperatures (up to +250°C)
- Maintains flexibility in aggressive environments

🔧 Automotive Performance Comparison

Material	Fuel Resistance	Temperature Resistance	Application Lifespan
NBR	Good	Up to +120°C	2-3 years
EPDM	Poor	Up to +150°C	3-5 years
FKM (Viton)	Excellent	Up to +250°C	10+ years

✈️ Aerospace Industry

FKM materials are used in the aerospace sector where components are exposed to extreme temperatures, aggressive fluids, and demanding mechanical stress.

✅ Applications: O-rings, gaskets, fuel system seals, hydraulic system seals, engine compartment seals.
✅ Key Advantages:
- Maintains sealing integrity at altitudes and extreme temperatures
- Resistant to jet fuels, lubricants, and aggressive chemicals
- Low outgassing properties suitable for high vacuum systems

🔧 Aerospace Performance Comparison

Material	Fuel & Chemical Resistance	Operating Temperature	Application Lifespan
Silicone (VMQ)	Moderate	-60°C to +230°C	5-10 years
FKM (Viton)	Excellent	-20°C to +250°C	10-15 years
FVMQ	Good	-60°C to +230°C	8-12 years

⚗️ Chemical Processing Industry

FKM is highly valued in chemical processing plants for its resistance to acids, alkalis, solvents, and hydrocarbons. It prevents leaks and degradation, ensuring process reliability and safety.

✅ Applications: Pipe seals, pump seals, reactor gaskets, valves, and chemical-resistant hoses.
✅ Key Advantages:
- Resists over 300 chemicals including acids and bases
- Performs continuously at up to +250°C
- Minimizes downtime due to component failure

🔧 Chemical Resistance Comparison

Chemical Type	EPDM	NBR	FKM (Viton)
Strong Acids	Poor	Moderate	Excellent
Hydrocarbons	Poor	Good	Excellent
Alkalis	Good	Moderate	Excellent

⛽ Oil and Gas Industry

In upstream and downstream oil & gas operations, FKM rubber parts are critical for maintaining integrity in drilling, refining, and transportation systems.

✅ Applications: Blowout preventer seals, refinery gaskets, pipeline seals, valve seats, and O-rings in drilling equipment.
✅ Key Advantages:
- High resistance to crude oil, natural gas, and aggressive drilling fluids
- Performs at high temperatures and pressures
- Reduces risk of leaks and blowouts

🔧 Oil & Gas Performance Requirements

Requirement	FKM (Viton)	NBR	HNBR
High Pressure Sealing	Excellent	Good	Excellent
High Temp Tolerance	+250°C	+120°C	+150°C
Chemical Resistance	Excellent	Moderate	Good

🏥 Pharmaceutical & Food Industry

FKM materials are increasingly used in pharmaceutical and food applications, where hygiene, chemical resistance, and compliance are key concerns.

✅ Applications: Seals and gaskets in pharmaceutical reactors, sterile piping systems, food processing valves, and pumps.
✅ Key Advantages:
- FDA and USP VI compliant grades available
- Resistant to cleaning agents, steam, and CIP/SIP processes
- No contamination, low extractables

🔧 FDA and Pharmaceutical Compliance Table

Criteria	FKM (FDA Grade)	EPDM	Silicone
FDA Compliance	Yes	Yes	Yes
CIP/SIP Resistance	Excellent	Good	Moderate
Steam Resistance	Good	Excellent	Poor

Why is Fluorocarbon Expensive?

The high cost of fluorocarbon rubber (FKM/Viton) comes from:

✅ Complex manufacturing process requiring high-purity fluorinated monomers
✅ Specialized production and curing equipment
✅ Superior performance characteristics in extreme environments
✅ Lower production volumes compared to general elastomers like EPDM

Although costly, its extended service life and superior performance often justify the investment in critical applications.

How to Choose Viton Rubber Parts?

Viton, also known as FKM, is a premium-grade fluoroelastomer used in seals, gaskets, and O-rings. It is ideal for environments with aggressive chemicals, fuels, and high temperatures. However, not all Viton parts are the same, and choosing the wrong grade can lead to premature failure and costly downtime.

The right Viton rubber part depends on its grade, hardness, temperature resistance, chemical compatibility, and industry certification.

🔍 Step 1: Define the Application Environment

Identify the working conditions of your equipment, including:

✅ Temperature extremes (continuous and peak temperatures)
✅ Chemical exposure (fuels, acids, solvents, gases)
✅ Pressure and mechanical stress levels
✅ Exposure to UV, ozone, and weathering

Viton Grades and Their Application Temperatures:

Viton Grade	Continuous Temperature	Peak Temperature	Best Application
Viton A	-20°C to +200°C	Up to +250°C	Automotive, fuel systems, hydraulic seals
Viton B	-20°C to +200°C	Up to +250°C	Chemical processing, acids, alkaline resistance
Viton F	-15°C to +225°C	Up to +275°C	Aggressive chemicals, high-pressure fuel systems
Viton ETP	-20°C to +230°C	Up to +300°C	Pharmaceuticals, semiconductor, universal chemical resistance

🔍 Step 2: Select the Correct Hardness (Shore A)

Hardness impacts the flexibility, sealing strength, and pressure resistance of Viton parts. Shore A hardness typically ranges from 50 to 90, and the choice depends on your application:

✅ 50-60 Shore A: Soft, flexible seals and O-rings (low-pressure environments)
✅ 70 Shore A: Standard hardness for most gaskets and O-rings
✅ 80-90 Shore A: High-pressure systems, heavy-duty mechanical seals

🔍 Step 3: Verify Chemical Compatibility

Viton rubber offers excellent resistance to most chemicals, but it’s essential to verify compatibility, especially for:

✅ Fuel and petroleum products
✅ Hydraulic fluids (including phosphate esters)
✅ Acids and alkalis
✅ Solvents, ketones, and esters

Chemical Compatibility Quick Reference:

Chemical Type	Compatibility
Petroleum Oils and Fuels	Excellent
Strong Acids (Sulfuric, Nitric)	Good (Viton B and F grades)
Aromatic Hydrocarbons (Benzene, Toluene)	Excellent
Ketones (Acetone, MEK)	Poor (Not Recommended)
Phosphate Ester Fluids	Poor (Use EPDM instead)

🔍 Step 4: Check for Industry Certifications

For industries like food, medical, and aerospace, certification is mandatory. Ensure the Viton parts meet required standards:

✅ FDA compliance (for food and pharmaceutical applications)
✅ UL listing (for flame resistance)
✅ ISO 3601 (for O-rings and sealing parts)
✅ SAE AMS specifications (for aerospace seals)

🔍 Step 5: Understand the Cost vs. Performance Ratio

Viton rubber parts are more expensive than standard elastomers like NBR or EPDM. However, they provide superior performance and longer service life, reducing maintenance costs in harsh environments.

Cost Comparison Table:

Material	Relative Cost	Typical Service Life
NBR (Nitrile)	Low	1-2 years (moderate conditions)
EPDM	Low-Medium	2-5 years (weather/steam applications)
Silicone	Medium	5-10 years (extreme temperatures)
Viton (FKM)	High	10+ years (aggressive chemicals/high heat)

📞 Get a Free Quote or Sample of FKM/Viton Rubber Products!

Looking for reliable FKM/Viton rubber seals, O-rings, or custom-molded parts? We offer high-quality, performance-driven solutions tailored to your industry needs.