[Jeffrafa]

Looks sharp.

Your high pressure pneumatic circuit appears to be Y split to two regulators. R71 specifies that working pressure must be provided through one primary regulator.

If you want two different working pressures (say 60 psi and 30 psi), it is just a matter of hooking the regulators in series rather than parallel to satisfy the rule.

Also, what is the purpose of the manual valve just above the lower pressure gauge? It would seem to isolate the 'stored' and 'working' sides of the pneumatic system if closed. Inspectors may find issue with this due to R78. If this valve is ever closed, then opening the pressure vent plug would not relieve all stored pressure.