1. In environments with saturated water vapor, boiling water, or intermittent high temperatures >125℃;
2. Compression set is a key performance indicator, requiring long-term rebound sealing during thermal cycling;
3. The medium is water, coolant, weak acids or alkalis, and free of mineral oil;
4. Low exudation is required, and it must be suitable for drinking water/food contact;
5. Severe thermal-oxidative aging and ozone aging requirements.