GEA PHE gaskets

Common gasket polymers: 

- NBR
- EPDM
- FKM.
Chemical Resistance 
Each rubber material has its unique resistance towards various chemicals. Polymer used, as well as additives, effect which chemicals each rubber material is suitable for.
High Temperature 
At high temperatures the rubber will be attacked faster by the chemicals in use, and the surrounding oxygen. The oxidation process will either make the rubber harder (the most common one) OR make it softer (less common), OR both at the same time. Either way the change in properties will reduce the performance. All rubber materials have a maximum continuous temperature, which should not be exceeded to maintain good performance and to achieve a reasonable lifetime.
Low Temperature 
At low temperatures the stiffness increases, and the elasticity decreases. This influences the sealing force of the gaskets. All rubber materials have a certain lowest temperature that have to be exceeded to be able to perform well enough as a gasket.
Food Applications 
For food applications there are demands according to international standards. The usual one for PHE gaskets is FDA (USA). This standard regulates what additives are allowed to be used in the rubber and to what content. It also sets demands on what tests have to be done to ensure the quality level.