Low-temperature valves (P, U, EE class, -75°F) use special low-Tg HNBR or FKM compounds that retain elasticity below -40°F. Brittle-point and TR-10 tests confirm sealing capability during cold start-ups in arctic and subsea environments without cracking or leakage. https://globalsealstech.com/product-category/oil-gas-seals/api-6a-gate-valve-seals/