Material Operating Limits
| PPE Grade | Material Type | Description | TR10 °C / °F | Tg °C / °F | Operating Temperature | |
| (°C) | (°F) | |||||
| EnDura® A90H | FEPM | Aflas® based copolymer | - | 0 / +32 | 0 to +250 | +32 to +482 |
| Perlast® G92E | FFKM | RGD & chemical resistant grade | -8 / +18 | -7 / +19 | -15 to +260 | +5 to +500 |
| EnDura® V91A | FKM | Ultra-low temperature grade | -46 / -51 | -44 / -47 | -51 to +225 | -60 to +437 |
| EnDura® V91K | FKM | Low temperature grade | -35 / -31 | -35 / -31 | -41 to +225 | -42 to +437 |
| EnDura® Z95X | HNBR | General purpose grade | - | -27 / -17 | -29 to +180 | -20 to +356 |
As materials cool they become steadily stiffer, ultimately becoming glassy and brittle. TR10 (ASTM D1329) and Tg (ASTM D7426) seek to give guidance as to when this occurs. Sealing has been shown to be possible below this temperature; which is reflected in part in the lower operating limit. The change to a glassy state is completely reversible, unlike the degradation that takes place at elevated temperatures. All seals have a finite life, the upper operating limit seeks to give a guide as to the point at which an appreciable life can be attained. Neither of these temperatures are absolute limits and short-term excursions are possible above the upper limit and in some situations sealing is possible below the lower limit; in certain cases far below.
EnDura® and Perlast® are registered trademarks of Precision Polymer Engineering.
Aflas® is a trademark of the Asahi Glass Company.