What is an essential safety feature in steam systems to prevent overpressure?

A relief valve is crucial in steam systems as it serves as a safety mechanism designed to prevent overpressure conditions. When the pressure within the steam system exceeds a predetermined limit, the relief valve automatically opens, allowing excess steam to escape safely, which helps maintain the system's pressure within safe operational parameters. This function is vital in protecting equipment, piping, and personnel from the dangers associated with overpressure, such as ruptures or explosions.

In contrast, while control valves and pressure regulators manage and maintain specific pressure levels within the system, they do not provide a safety release for excess pressure. Similarly, flow switches monitor the flow rate of steam or water but do not address issues related to pressure control. Therefore, the primary role of the relief valve as a fail-safe device against overpressure incidents makes it an essential feature in steam systems.