Which of the following best describes the function of pressure relief valves?

Pressure relief valves are essential components used in various systems to maintain safety and prevent potentially hazardous overpressure situations. Their primary function is to open at a predetermined set pressure and allow excess fluid or gas to escape from the system, thereby reducing pressure to safe levels. This action is critical in preventing equipment failure, ruptures, or explosions that could occur due to excessive pressure build-up.

While other options mention maintaining pressure, regulating flow rates, and monitoring temperature, none of these represent the fundamental role of pressure relief valves. They do not function as pressure regulators, which are designed to maintain constant pressure. Additionally, while flow rates may be affected indirectly by the operation of a pressure relief valve due to changes in pressure, the primary purpose is not to control flow rates. Similarly, monitoring temperature is outside the operational scope of pressure relief valves, which are specifically focused on pressure management. Therefore, the correct representation of a pressure relief valve's function is its role in preventing overpressure conditions.