Technical Information on Material Seals
Knowledge of the fluid's concentration, temperature and degree of contamination are crucial to making the right material selection. Further relevant criteria are operating pressure and maximum flow rate. In addition to operational temperature, high pressure levels and velocities of flow need also to be considered when choosing appropriate materials.
NBR - acrylnitrile-butadiene rubber
- Standard elastic material for neutral fluids such as air, water and oil. Shows good resistance to mechanical stress. Temperature range depending on load from -10 °C to + 90 °C.
HNBR - hydrogenated nitrile rubber
- Many properties are similar to NBR. Particularly suited for hot water and steam. Temperature range, depending on load, from -20 °C to +150 °C.
EPDM - ethylene-propylene rubber
- Resistant to alkalis and acids of medium concentration, water, hot water and steam. Not resistant to oils and fats. Temperature range, depending on load, from -20 °C to +130 °C.
FPM - fluoro rubber
- Elastomer with high temperature and weather resistance. Suitable for work with many acids, bases, fuels and oils (including synthetic oils). Unstable with steam. Temperature range, depending on load, from -10 °C to +180 °C.
CR- chloroprene rubber
- Many properties are similar to NBR. Particularly suitable for most refrigerants. Temperature range, depending on load, from -20 °C to +90 °C.
PTFE - polytetrafluoroethylene
- Not an elastic material and as such not suitable for 'classic' membranes, although separating foils are possible. The material's resistance is almost universal in the temperature range from -20 °C to +200 °C.
FFPM - perfluoroelastomer
- An elastic material with resistance properties similar to PTFE. Excellent sealing properties. Temperature range, depending on load, from -30 °C to +200 °C.
TPE - thermoplastic elastomers
- High wear resistance and flexibility over a wide temperature range. Resistant to oils, fats, many solvents and weathering.