At what setting should safety and safety relief valves be calibrated?

Safety and safety relief valves should be calibrated at the nameplate pressure rating of the boiler because this is the maximum allowable working pressure specified by the manufacturer. Proper calibration at this setting ensures that the valves will function correctly when needed, protecting the system by releasing excess pressure that could lead to dangerous situations, such as equipment failure or explosions. The nameplate pressure represents the highest operating condition that the equipment is designed to handle safely. Thus, validating the valve's performance against this benchmark is critical to maintaining the safety and integrity of the boiler system. Calibration at the nameplate pressure also ensures compliance with regulatory standards and best practices in mechanical system safety.