What is the maximum pressure above the MAWP that power actuated relieving valves can handle?

Power actuated relieving valves are designed to relieve pressure in a system to prevent overpressure situations that could lead to equipment failure or dangerous incidents. The maximum pressure above the Maximum Allowable Working Pressure (MAWP) that these valves can handle is typically set at 20% above the MAWP. This design consideration ensures that in the event of a pressure spike or unexpected surge, the relieving valve will function effectively to release excess pressure without compromising the safety of the boiler or system.

Following this guideline, having a limit that is too high could risk system integrity and safety, while having a lower limit may not adequately address certain operational pressures that could occur during abnormal conditions. Therefore, the 20% threshold strikes a reasonable balance between safeguarding the system and ensuring proper functioning of pressure relief mechanisms.