Mechanical pressure safety - what valves do I need?

[sensei247]

I’m building a fully automated fermentation controller (Brucontrol) and want to ensure pressure (positive and negative) can be mechanically prevented given computer programming will drive this process. Mechanically, I’m making a safety assumption there could be faulty sensors, gas leaks, bad calibration, etc and want to ensure I’m protected in all events.

What is the best approach to
Protect myself from positive AND negative pressure assuming I will be doing every cold side step in a spike CF10 unitank? A few thoughts
+ All pressure sensors and mechanical gas PRVs/valve/breakers will be connected to a 4-way TC fitting on unitank lid
+ I am currently thinking I’ll use 3 separate mechanical devices for backup protection in the event 1 mechanical pressure relief fails and to protect against + and - pressure- those 3 are
1) Spike gas manifold with 14-15psi PRV- first line of defense for over pressurization. Also has a built in gauge+port for attaching #3 below
2) 1bar TC vacuum breaker preventing NEGATIVE pressure during cold crash (my co2 algorithms will pump co2 during crash but the breaker is a mechanical safety in case of software failure)
3) spunding valve attached via ball lock- this has a mechanical spunding valve AND solenoid attached (not pictured)- this device is a mechanical PRV backup AND helps regulate tank pressure via solenoid Brucontrol algorithms.

What is the best approach to this without going full overkill on numerous potentially unnecessary mechanical safety mechanisms?

The 3 pressure valves are pictured below