Material qualification follows API 6A F.1.13 (RGD) and F.1.11 (sour fluid aging). Compounds must survive 10 rapid decompression cycles from 20,000 psi CO₂ at 250°F without cracking and retain >70% properties after 160 hours 10% H₂S at 350°F, mandatory for North Sea and Middle East sour fields. https://globalsealstech.com/product-category/oil-gas-seals/api-6a-gate-valve-seals/