API 6D ball valves for LNG service require seals capable of maintaining zero leakage at -196°C and high pressure. Special cryogenic sealing systems combine spring-energized PTFE jackets, PCTFE seats, and low-temperature lip seals to achieve bubble-tight shutoff per BS 6364 and Shell MESC SPE 77/200 standards. https://globalsealstech.com/product-category/oil-gas-seals/api-6d-ball-valve-and-lng-seals/