The Chevy Corvair was born with a heart defect. You see, after about 15,000 miles, the neoprene seals on the push rods would start to fail, and oil and gas would mix in the combustion chamber.

Not good.

The heat in the engine, and the petrochemicals, was destroying the seals.

The solution? Viton Rubber seals. 

Viton rubber, it turns out, is a far superior material for this extreme environment and saved this American Classic from the junk heaps.

All because of a handful of high-performance Viton rubber gaskets.   

What Is Viton Rubber?

  • Viton rubber was the brand name for DuPont’s line of fluorocarbon rubber products, and is also commonly referred to as a ‘fluorine rubber’ or ‘fluoro rubber.’
  • Viton rubbers are synthetic rubber and fluoropolymer elastomers that can withstand high temps, petrochemicals, and extreme weather compared to other polymers.
  • Compared to other elastomers, Viton rubber has a very high density of over 1800 kg/m3.
  • Viton Material can be used to make just about anything that needs to perform in extreme conditions where normal rubber just won’t cut it.
  • Dupont’s original patent is now owned by Chemours. However, Viton is now being made by many companies around the world.
  • FKM, Viton, Chemours, and FPM are all different trade names for the same thing: Viton material.

What Is Viton Rubber Used For?

Viton rubber is a natural choice in the oil and gas refining industry. Viton gaskets and seals are heavily used in food and pharma as well – especially where it comes into contact with “aggressive” liquids. These polymers are also used in the automotive and aerospace manufacturing spaces.

Viton is commonly used for:

  • O-rings, gaskets, and other engine parts
  • Molded or extruded parts
  • High temperature applications that destroy normal rubber
  • Aggressive chemicals that normal rubber can’t handle
  • Environmental challenges like mold, algae, and sun that attack normal rubber

The Four Types of Viton Rubber

  • Type-1 are the standard type of FKMs, showing a good overall performance. Their fluorine content is approximately 66 weight percent.
  • Type-2 have a higher fluorine content compared to copolymers, which results in better chemical and heat resistance. Compression set and low temperature flexibility may be affected negatively.
  • Type-3 FKMs provide better low temperature flexibility. Typically, the fluorine content of type-3 FKMs ranges from 62 to 68 weight percent.
  • Type-4 FKMs While base resistance is increased in type-4 FKMs, their swelling properties, especially in hydrocarbons, are worsened. Typically, they have a fluorine content of about 67 weight percent.
  • Type-5 FKMs are known for base resistance and high-temperature resistance to hydrogen sulfide.

What Are The Limitations of Viton Rubber?

  • Much more expensive than other rubbers
  • Low performance in extremely cold situations
  • In a fire, Viton rubbers release hydrogen fluoride, so any residue must be handled using protective equipment.

Key Takeaways:

  • Viton has several trade names, and several varieties, and is not all produced by Chemours.
  • Viton is expensive, but has some very specific properties that make it the best choice for high-performance gaskets and o-rings.
  • Viton can be molded or extruded into just about any shape.
  • The Chevy Corvair is recovering nicely from its open heart surgery. 

If you need to know more about Viton and how it can save your Corvair too, please don’t hesitate to contact us. This stuff can get confusing and we are here to help.