Official Answer
Answer
In hydraulic seals, a wave spring provides a constant face load. If the mating surfaces are not parallel (angular misalignment), the spring will be compressed more on one side than the other. This creates a non-uniform stress distribution and causes the spring to tilt. Visual inspection will show 'polishing' or wear on the edges of the spring on one half of the circumference and perhaps no contact on the other. This uneven loading leads to localized overheating and can cause the spring to 'set' prematurely on the heavily loaded side, resulting in a loss of sealing pressure and leakage. The assembly must be checked for perpendicularity of the spring pocket to the seal axis.
