Regarding the pressure of the nitrogen seal valve

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I’ve read some information stating that nitrogen seals are generally designed with a slight positive pressure, with typical pressures ranging from 1 kPa to 2 kPa. Automatic pressure regulation is achieved using nitrogen seal valves and vent valves. I have a project where the vent valve is used only to prevent vacuum conditions, while a safety valve is used to activate when overpressure occurs. Here’s my question: if the nitrogen seal pressure is 1 kPa when the tank is full of material, then as the amount of material in the tank decreases during use, the nitrogen seal valve will activate and maintain a pressure of 1 kPa. When more material is added next time, the pressure will inevitably increase, possibly reaching around 7 kPa. Can I set the safety valve at 8 kPa or something similar? In this way, the safety valve hardly requires pneumatic power, and it seems that the nitrogen inside also doesn’t need to be replaced frequently. This is different from conventional breathing valves, which are set at 2 kPa to allow some of the nitrogen to be released during feeding. (PS: I’m dealing with an ammonia storage tank; the tank is designed as a pressure vessel with a design pressure of 0.5 MPa.)