In a fixed CO2 fire extinguishing system where pressure from pilot cylinders is used to release the CO2 from the main bank of cylinders, the number of required pilot cylinders shall be at least __________.

Correct Answer: Option A — 2

To ensure absolute reliability in pneumatically actuated fixed CO2 systems, 46 CFR regulations specify that at least two independent pilot cylinders must be employed to provide redundant pressure for releasing the main cylinder bank.