What diameter should the discharge pipe of safety and relief valves have?

The discharge pipe of safety and relief valves is required to have the same diameter as the valve outlet to ensure effective operation and prevent backpressure that could cause the valve to malfunction. If the diameter were smaller, it could lead to restrictions in flow, creating increased pressure within the system and potentially preventing the valve from opening at its designed setpoint, which could endanger the system and compromise safety.

Having the same diameter as the valve outlet allows for uninterrupted flow during discharge, ensuring that the system can vent excess pressure fluid efficiently. This is crucial in applications such as boilers and pressure vessels where safety is of utmost importance. Maintaining this specific sizing helps to uphold the integrity of the safety systems in place and follows codes and regulations governing mechanical systems.