Surface finish requirements on sealing surfaces affect LNG seal performance and longevity. Ball surfaces require precise sphericity and smoothness typically 8-16 microinch Ra. Stem surfaces need 8-32 microinch Ra finishes. Seat sealing surfaces demand controlled roughness ensuring seal conformability. Hard coatings like chrome or tungsten carbide enhance wear resistance. Proper surfac... https://globalsealstech.com/product-category/oil-gas-seals/api-6d-ball-valve-and-lng-seals/