Thermal cycling resistance is critical as LNG valves experience repeated temperature transitions between ambient and cryogenic conditions during normal service. Seals must maintain integrity through hundreds or thousands of thermal cycles without developing leakage paths from thermal fatigue, compression set, or dimensional instability caused by repeated thermal shocking. https://globalsealstech.com/product-category/oil-gas-seals/api-6d-ball-valve-and-lng-seals/