Aflas® Temperature Resistance: -5°C to +205°C
Viton® Temperature Resistance: -15°C to 200°C
On the whole there are pros and cons with both materials at temperature extremes. Aflas® can withstand higher temperatures and Viton® performs better at low temperatures. A point often overlooked is the test data doesn’t always reflect the compound performance. In reality, Aflas® exhibits a poor compression set at high temperatures, making it better suited for static applications. Compression set is as percentage of how much much memory is lost after the elastomer is compressed, a higher compression set indicates the O-ring will not fully recover its form.
Otherwise, the two compounds offer very similar data sets. Between our two standard examples, Aflas® showed a slight improvement for results in tensile strength, elongation, modulus and specific gravity.
This is where the two compounds really differentiate, because Aflas® is impervious to a wider range of chemicals. Viton® is generally recommended for contact with oils, greases and hydrocarbons. Such as the following:
Mineral oil and grease, ASTM oil No. 1, and IRM 902 and IRM 903 oils
Non-flammable hydraulic fluids (HFD)
Silicone oil and grease
Mineral and vegetable oil and grease
Aliphatic hydrocarbons (butane, propane, natural gas)
Aromatic hydrocarbons (benzene, toluene)
Chlorinated hydrocarbons (trichloroethylene and carbon tetrachloride)
Gasoline (including high alcohol content)
However, Viton® is not suitable for:
Glycol based brake fluids
Ammonia gas, amines, alkalis
Low molecular weight organic acids (formic and acetic acids).
This is where Aflas® proves to be a great replacement for Viton®. It’s well suited to a wide spectrum of automotive fluids and additives such as motor oils, engine coolants, rust inhibitors, EP gear lubricant, transmission or power steering fluid and brake fluids. Also, it’s compatible with superheated steam applications.
In summary, despite its raised compression set at high temperatures Alfas® makes a great choice for applications that make contact with chemicals that are not compatible with Viton®. For this reason, Aflas® is commonly used within thermal power plants, the oil and gas industry, chemical and nuclear plants and automotive industries.