How to solve the leakage of pressure comparator?

If there is air leakage in your pressure comparator, don't rush to say that there is a quality problem in the pressure comparator. In fact, most of the time, it is because we don't pay attention to some small places. If there is a pressure leakage, please first check it according to the following methods, and maybe solve your problem soon.
1. Check whether the pressure relief valve of the pressure comparator is closed