Spending more money always means something is better, right? When it comes to choosing to seal material, nothing could be more false. When comparing Buna rubber, (also known as Nitrile, Buna-N, Perbunan or NBR) and fluorocarbon (also known as Viton) both provide excellent compression set resistance and both are designed to resist most oils and lubricants, especially petroleum-based lubricants.
Viton is better at 200° F, but not necessarily at 140° F. That is where most applications are. So often I hear customers say “I don’t needViton but give me Viton so it will last longer” when picking a cylinder seal material. That’s flawed thinking. When buying seals, go to the charts. Choose the seal that works best for your application. Factor in wear, compatibility as well as cost. Buna works best for many cylinder applications.