Fire-safe design integrates secondary graphite seals in API 6D LNG valves. Per API 607, seals maintain low leakage after burn tests. Graphite backups activate if primary polymer melts, providing metal-to-metal sealing during fire scenarios in LNG terminals. https://globalsealstech.com/product-category/oil-gas-seals/api-6d-ball-valve-and-lng-seals/