What is the typical function of a pressure relief valve?

The typical function of a pressure relief valve is to prevent pressure build-up. This is crucial in maintaining safety within a boiler system. When a boiler operates, it generates steam and, consequently, pressure. If the pressure exceeds the maximum allowable limit, it could lead to equipment failure or even catastrophic explosions. The pressure relief valve is designed to open automatically when the internal pressure reaches a predetermined point, allowing excess steam to escape. This function not only protects the integrity of the boiler but also ensures the safety of personnel and facilities.

The other options do not accurately describe the primary purpose of a pressure relief valve. Regulating the fuel supply pertains to maintaining proper combustion within the boiler, controlling temperature relates to ensuring efficient operation, and filtering impurities from water is a function associated with water treatment rather than pressure regulation.