Perhaps one of the most popular types of materials for seals is Viton, and for plenty of reasons. In this article, we examine the common names out there, temperature and chemical ranges, types of resistances, types of parts commonly found on and more.
The best way to begin is by first understanding some common terms that will make everything much more clear, especially before researching and seeing all of the confusing and overlapping terminology for Viton and why you see FKM and FPM consistently referenced.
Viton, FKM, FPM?
You may see FKM quite often when searching for Viton and vice versa as well. You may even see FPM. It can be quite confusing, so lets break down exactly what and why there are 3 different names for this one material.
Fluoro-Elastomer was originally developed by Du Pont and VITON™ is their official trademark name. While now, their are multiple companies that produce Viton, they use different names but it is still common to refer to FKM and FPM as Viton, being the original name. Think Band-aid and Kleenex and how their products are their brand name as well and is interchangeable with bandages and tissues.
FKM simply is the American standard ASTM short form name for Fluro-Elastomer. It is the designation for around 80% of Fluoro-Elastomers defined by ASTM D1418. There is even a FFKM, or perfluoroelastomer which contains higher amounts of fluorine than standard FKM, and features higher temperature ratings, up to approximately 325°C.
And finally, FPM is Fluoro-Elastomer’s DIN/ISO international abbreviation (1629 standard) whereas FKM is the short form for the fluoroelastomer category according to the American standard ASTM.
Viton Material Specs
To truly appreciate just how amazing this rubber is, lets breakdown all the resistances and temperature ranges, just so you can have an idea of all the amazing properties and capabilities Viton offers;
- Common Name: Viton®, Fluro Elastomer, FKM
- ASTM D-2000 Classification: HK
- Chemical Definition: Fluorinated Hydrocarbon
- Resistances
- Abrasion Resistance: Good
- Tear Resistance: Good
- Solvent Resistance: Excellent
- Oil Resistance: Excellent
- Aging Weather/ Sunlight: Excellent
- Temperature Range
- Low Temperature Usage: 10°F to -10°F | -12°C to -23°C
- High Temperature Usage: 400°F to 600°F | 204°C to 315°C
- Durometer (Hardness): Range 40-90 Shore A
- Tensile Strength
- Tensile Range (P.S.I): 500-2000
- Elongation (Max %): 300
- General Characteristics
- Adhesion to Metals: Good
- Compression Set: Good
- Resilience/ Rebound: Fair
Viton Applications
Viton is the choice for use in aerospace and industrial equipment subjected to severe conditions. It was originally chosen due to its fuel resistance and low burning characteristics but has now made its way to many more industries.They can even be found in fluid power, automotive, appliance, and various chemical industries. In recent years, even food processing and pharmaceutical industries have embraced Viton.
Because of it high chemical resistance, common parts that need oil lubrication such as fuel seals, cap seals, T-seals, and radial lip seals in pumps are common parts that you you see these in. In the automotive industry you will more find these in gaskets, seals, o-rings, fuel hoses, and tubing. Beyond this, there are plenty of other parts in many industries that have FKM to be much more superior due its power UV exposure.
Viton vs. Other Materials
Viton vs Nitrile - Nitrile or NBR or Buna-N is a general all purpose cost effective rubber material that has a temperature range of -35°C to 120°C. Viton or FKM, is used in more specialty applications that require higher temperature and chemical resistance.
Nitrile Temperature Range -
- Low Temperature Usage: -30°F to -40°F | -34°C to -40 °C
High Temperature Usage: Up to 250°F | 121°C
- Oil Resistance: Good to Excellent
- Abrasion Resistance: Excellent
- Tear Resistance: Good
- Resistance: Good to Excellent
- Aging Weather/Sunlight: Poor
Viton vs EPDM - The primary differences between Viton and EPDM is in their chemical resistance and temperature ranges. Both are excellent for extreme temperatures, but EPDM has a slight edge in colder temperatures, while Viton is better for heat resistance at higher temperatures.
EPDM Temperature Range -
- Low Temperature Usage:-20° to -60° F | -29⁰C to -51⁰C
- High Temperature Usage: Up to 350° F | Up to 177⁰C
EPDM Resistance -
- Aging Weather - Sunlight: Excellent
- Abrasion Resistance: Good
- Tear Resistance: Fair
- Solvent Resistance: Poor
- Oil Resistance: Poor
Viton vs Teflon (PTFE) - Viton offers a greater temperature resistance but falls short of Teflons(PTFE) chemical resistance. Also, Teflon is slightly less thermally resistant but offers much more in the way of non-adhesive properties. And lastly due to the rigidness of the plastic on teflon, Viton offers a much more capable sealing ability.
Teflon (PTFE) Temperature Range -
- Low Temperature Usage: -400°F to 400°F | -688°C to -752 °C
- High Temperature Usage: Up to 500º F (260 C)
Teflon (PTFE) Resistance -
- Aging Weather - Sunlight: Excellent
- Abrasion Resistance: Fair
- Tear Resistance: Good
- Solvent Resistance: Excellent
- Oil Resistance: Excellent
Viton vs Silicone - Silicone rubber can be found applied to high-temperature applications or where damage from the elements may be a factor. But because of its lack of tear and abrasion resistance, they are restricted to static rather than dynamic applications.
Silicone Temperature Range -
- Low Temperature Usage: -60° to -150° F | -50°C to -100°C
- High Temperature Usage: Up to 480° F | Up to 250°C
Silicone Resistance -
- Abrasion Resistance: Fair to Poor
- Tear Resistance: Poor
- Solvent Resistance: Poor
- Oil Resistance: Fair to Poor
- Aging Weather - Sunlight: Excellent
Where To Buy Viton Seals?
If you find Viton is the type of seal you need, then please feel free to reach out to us or even head on over to our Viton selection of O-rings. Remember, if you don't see the product you are looking for, reach out to us by email, phone, social media or even our live chat option. We would be more than happy to help you find the right seal for the right job.