Cryogenic conditions in LNG service cause material contraction and embrittlement risks. Seals prevent leakage of flammable LNG while handling rapid temperature swings from ambient to cryogenic. API 6D requires valves to pass low-temperature testing, including seat and shell tests at reduced temperatures. Seals like PCTFE or modified PTFE retain flexibility and low friction at -196°C, ... https://globalsealstech.com/product-category/oil-gas-seals/api-6d-ball-valve-and-lng-seals/