What happens when a safety valve operates?

When a safety valve operates, it serves the critical function of releasing built-up pressure within a system, such as a boiler. This is vital for maintaining safety, as excessive pressure can lead to equipment failure or even catastrophic incidents. The safety valve is designed to open at a predetermined set point, allowing steam or gas to escape and thereby reducing pressure to safe levels. By doing so, it helps protect the integrity of the boiler and other connected equipment from damage caused by overpressure conditions. This function is essential in preventing accidents and ensuring safe operation in power engineering contexts. The other options suggest actions that do not align with the primary purpose of a safety valve during an overpressure event.