What about Kalrez O-Rings?
DuPont™ Kalrez® perfluoroelastomer parts (FFKM) resist over 1,800 different chemicals, while offering the high temperature stability of PTFE (327°C).
They’re used in highly aggressive chemical processing, semiconductor wafer fabrication, pharmaceutical, oil and gas recovery, and aerospace applications. The long-term, proven performance of Kalrez® parts can mean less frequent seal changes, repairs and inspections.
Comparison of O-Ring Materials
Each type has its advantages and disadvantages as listed in the chart below, and the type required depends on the O-Ring application.
| Property | Buna-N | FKM | Silicone | PTFE | Kalrez® |
| Tear Resistance | Good | Good | Poor | Excellent | Good |
| Abrasive Resistance | Good | Good | Poor | Excellent | Good |
| Ozone Resistance | Poor | Excellent | Excellent | Good | Excellent |
| Weather Resistance | Fair | Excellent | Excellent | Good | Excellent |
| Heat Resistance | Fair | Excellent | Excellent | Good | Excellent |
| Chemical Resistance | Fair | Excellent | Good | Excellent | Excellent |
| Oil Resistance | Poor | Excellent | Poor | Good | Excellent |
| Acid Resistance | Fair | Excellent | Good | Excellent | Excellent |
| Alkali Resistance | Good | Good | Fair | Excellent | Excellent |
| Steam Resistance | Fair | Fair | Poor | Good | Excellent |
| Minimum Usable Temp |
-65 deg F -54 deg C |
-65 deg F -54 deg C |
-120 deg F -85 Deg C |
-110 deg F -79 deg C |
-20 deg F -30 deg C |
| Maximum Usable Temp |
300 deg F 150 deg C |
500 deg F 260 deg C |
450 deg F 232 deg C |
500 deg F 260 deg C |
600 deg F 316 deg C |
| Color | Black | Black | Red | White | Black |
| Impermeability | Fair | Good | Poor | Excellent | Good |
| Tensile Strength | Good | Good | Poor | Excellent | Good |
Kalrez is available in a small number of sizes, with other sizes available through special order. Check the O-Ring Special Materials sections of our website for in stock items 24/7 or call us at 1 (800) 445-7803.