The API 6D standard mandates full or reduced bore designs, with full-opening valves allowing unobstructed flow for pigging operations common in LNG pipelines. For cryogenic LNG service, valves often incorporate extended bonnets to protect stem seals from extreme cold, preventing loss of elasticity in packing materials and ensuring reliable operation during thermal cycling. https://globalsealstech.com/product-category/oil-gas-seals/api-6d-ball-valve-and-lng-seals/