Viton® FAQ - Frequently Asked Questions
If you can't find the answer to your viton question here then visit our Technical Literature Library
where you will find downloadable brochures and technical documents
about the various grades of viton® we supply, or alternatively email us your enquiry directly.
What is Viton?
Viton® is a trade name for a fluoropolymer elastomer produced by Dupont Performance Elastomers. It is important to note that Viton® has become a generic reference within the Seals Industry, in much the same way that, say, a Hoover is used to describe a vacuum cleaner.
Is there such a thing as a standard Viton grade?
Yes there is. Viton A grade (66% fluorine content) is the most standard material from a stock-holding and general availability prospective. The material out of which the seals are produced generally, as a minimum, has to conform to certain industry standard criteria set out for that material classification. The criteria used is normally to requirements set out in ASTM D2000. One particular key attribute is its excellent compression set.
What is the upper temperature limit of Viton
The upper limit is around 200 deg C, and can go higher in certain situations, but it depends on the actual application. Dichtomatik has detailed knowledge of application and materials so it is better to provide full application criteria if known.
Can Viton resist steam ?
This is where it gets a little tricky. Many people associate temperature as the be all and end all no matter what other application criteria is involved. Water turns to steam at 100 deg C. We have already said that the upper temperature limit of Viton is 200 deg C so surely it should be OK? Not so I am afraid. Due to the crosslinking make up of standard vitons the additives used do not react too well with steam and create an effect known as hydrolysis which effectively over time breaks down the Polymer chain. Now the good news. Please visit the Q & A's under the heading of Viton APA to see how we can help with this application.
What is the lower temperature limit of Viton?
You have to remember that, in general terms Viton is mainly selected for its excellent chemical resistance, often at high temperatures and in the first case was not designed with low temperature in mind. Having said that it is a matter of - "How low do you want to go? With a Viton A grade-15/ -20 deg C is generally achievable. There are numerous laboratory tests. Within ASTM D2000 a 3 minute none brittle test is the norm(ASTM D2137) whereas the more clearly defined industry test is the temperature retraction test (known generally as TR-10, i.e the temperature at which an elastomer is able to retract 10%. See ASTM D1329) The material will probably be able to go approx.. 10 deg lower than this, but this is only a guide as the end result can be greatly affected by other application criteria, such as chemical contact media.. More good news - see Viton APA FAQ's to see which of the Viton Grades offers the lowest temperature resistance.
How do I know I am getting original Viton and not an alternative?
Firstly, please stipulate DUPONT VITON. As mentioned earlier, there is much confusion brought about due to the fact that so many people refer to Viton, even when it is not. Made with original Viton stickers can be affixed to the packaging, but the simple way is to state DUPONT VITON.
General Note : It is important to note that the information detailed herein is as a guide only. The responsibility is with the client to be sure that the product meets its required purpose via their own tests. Results from data sheets are usually based on tests of solid test buttons of a fixed size, shape and mass and tested in laboratories with controls maybe far different from those conducted elsewhere. The results on the component pieces will generally be considerably different to test piece results due to differing size, shape & mass.
There are many factors which result in reduction in seal life or failure, such as selecting wrong material, incorrect installation and so on. Elastomeric Science is an imprecise art, and all application criteria has to be considered in order to ensure the selected material has the best possible chance of success in the application.
Please note:, Sealing performance in service must also include considerations of other factors such as resistance to compression set, mechanical strength at service temperatures, seal design, and seal cost.