API 6D requires marking of cryogenic valves with CT (cryogenic tested) designation. LNG valves display maximum and minimum design temperatures permanently. Seal identification includes batch numbers laser-etched on spring components. Valves achieve NACE MR0175/ISO 15156 compliance for sour service with 22 HRC maximum hardness. The weld procedures qualify with 42 J lateral expansion at... https://globalsealstech.com/product-category/oil-gas-seals/api-6d-ball-valve-and-lng-seals/