What action does a pressure relief valve perform when pressure exceeds the set limit?

When pressure exceeds the set limit, a pressure relief valve opens to allow the release of pressure. This action is crucial for safety in any system that operates under pressure, such as boilers, pressure vessels, and piping systems. The primary function of a pressure relief valve is to prevent potential damage or catastrophic failure that could result from excessive pressure build-up.

By opening when the pressure threshold is surpassed, the valve allows the excess pressure to escape, thereby protecting the integrity of the system and maintaining safe operating conditions. Once the pressure drops below the set limit, the valve will close again, returning to its normal state.

Choosing this action reflects the fundamental operational principle of pressure relief valves in maintaining system safety and stability.