What is the main function of the safety valves in the CPCS?

The main function of safety valves in the Cabin Pressure Control System (CPCS) is to relieve excess pressure. These valves are crucial for maintaining the safety and integrity of the pressurization system within the aircraft. If the cabin pressure exceeds predetermined limits, the safety valves open to release the excess pressure, preventing potential structural damage or failure of the pressurization system. This feature ensures that the aircraft maintains a safe environment for both the passengers and crew during flight, especially at high altitudes where the atmospheric pressure is significantly lower.