For subsea LNG applications, API 6D ball valves use ROV-operable designs with 5000 m rating. LNG seals incorporate metal-to-metal primary sealing with TCC coating achieving zero leakage at 345 barg and -196°C. The hyperbaric testing simulates 500 bar external pressure. Stem seals use three-stage graphite packing with Inconel springs. Valves achieve API 6DSS qualification with 20-year ... https://globalsealstech.com/product-category/oil-gas-seals/api-6d-ball-valve-and-lng-seals/