What is a frangible disk used for in a safety relief valve?

A frangible disk is a crucial component in a safety relief valve that functions to prevent overpressure conditions in gas storage and distribution systems. When the pressure exceeds a predefined limit, the frangible disk is designed to fragment or rupture, thus allowing the excess pressure to escape. This rapid release of pressure helps to prevent potential hazards like tank ruptures or explosions that could occur if the pressure continues to build beyond safe operational levels.

This feature is essential for maintaining the integrity of the system and ensuring safety. The design of the frangible disk ensures that it can reliably break apart under specific high-pressure conditions, acting as a fail-safe mechanism. In contrast to the other options, the frangible disk does not melt under high temperatures, gradually release pressure or maintain a constant pressure—its primary role is the immediate and sudden release of excess pressure to protect both the equipment and the surrounding environment from dangerous situations.