Material selection
Material selection can be problematic as the correct choice will always be a compromise between price, performance and availability.
The following factors need to be considered:
- Temperature (ambient and operating)
- Media (the gas or fluid being sealed)
- Pressure
- Environmental e.g. UV or Ozone
- Possible contact with cleaning agents e.g. Caustic Soda
- Unusual fitting procedures
- Special approvals: WRAS, FDA, NSF, USP Class VI, USDA-3A, UL, DTD, Mil…
In most applications standard stocked materials will give excellent performance, whilst applications requiring special compounds parts will need to be manufactured.
Below are listed the most popular materials, and the following pages provide an generic overview for each of the listed compounds.
Nitrile | EPDM | Fluorosilicone |
Carboxylated Nitrile | Chloroprene | TFE/Proplene (e.g. AFLAS®) |
Hydrogenated Nitrile | Polyurethane | Epichlorohydrin |
Fluoroelastomer | Silicone | Perfluoroelastomer |