Seat seals for API 6D ball valves in LNG service often use TFM 1600 or Kel-F (PCTFE) inserts. These provide low-torque operation and bubble-tight shutoff per API 6D requirements. Singapore's oil & gas sector values these for floating and trunnion designs in high-pressure LNG lines, where zero leakage is mandatory for safety. https://globalsealstech.com/product-category/oil-gas-seals/api-6d-ball-valve-and-lng-seals/