Official Answer
Answer
Nested wave springs consist of multiple turns coiled in parallel (stacked) rather than in series. The primary benefit is that the load capacity increases proportionally with the number of turns $n$, such that $P_{total} = n \times P_{single}$. This is particularly useful in subsea valve actuators where high force is required in a small radial envelope. In contrast, Crest-to-Crest springs are used to increase the total deflection while maintaining a lower spring rate, where the total rate $k_{total} = \frac{k_{turn}}{N}$. The nested design maintains a constant spring rate throughout its stroke, but requires careful lubrication between layers to prevent frictional hysteresis and fretting wear under high-frequency oscillation.
