The Pressure Relieve Valve has as main function to protect from overpressure or a too high working pressure (max1000psi/69bar).

The burst disk just protects the surroundings from exploding bottles.
About any modern industrial CO2 bottle is actualy a simular bottle as argon or such, therefor the test presure is 300 bar, and the working pressure 200 bar. This gives the reason for the 195 bar burst disk.

Paintball or Sodastream bottles sometimes have 135 bar burstdisks.