Die-formed graphite packing rings are individually density-controlled to 1.65–1.85 g/cm³ for optimal compressibility. This ensures uniform loading and sealing performance across wide temperature swings from -196°C to fire conditions, achieving API 607 fire-safe certification without leakage after cooldown. https://globalsealstech.com/product-category/oil-gas-seals/api-6d-ball-valve-and-lng-seals/