We conduct fatigue or life-cycle testing on bellows to assess durability under cyclic load conditions. By simulating pressure fluctuations, movement and thermal cycling, we verify design life and failure thresholds. Fatigue testing has been conducted under cryogenic conditions down to -168ᵒC and high-temperature conditions up to +1400ᵒC. Fatigue testing ensures long-term reliability, safety and performance in applications where repetitive stress may lead to material fatigue or failure.