Stem seals in API 6A gate valves use live-loaded spring-energized PTFE or hybrid graphite-free packing. They achieve ISO 15848-1 Class BH fugitive emissions and survive 200 temperature cycles without leakage, critical for actuated and manual valves in HPHT environments. https://globalsealstech.com/product-category/oil-gas-seals/api-6d-ball-valve-and-lng-seals/