A bellows assembly is configured to mount between a movable valve structure and a stationary valve structure of a valve assembly. The bellows assembly comprises a bellows and a spacer. The bellows is configured to compress until a gap is closed relative to the spacer. The bellows assembly is configured to bear a load through the bellows before the gap is closed, and the bellows assembly is configured to bear the load through the bellows and the spacer after the gap is closed.