Which component is crucial for controlling pressure in a boiler?

The safety valve is a critical component for controlling pressure in a boiler because it is designed to protect the system from excessive pressure buildup. When the pressure inside the boiler exceeds a predetermined level, the safety valve opens automatically to release steam or water, thereby preventing potential damage or catastrophic failure. This function ensures the safe operation of the boiler by maintaining pressure within safe limits.

In contrast, while the pressure gauge provides important information about the current pressure level, it does not actively control or manage the pressure. The thermostat is mainly responsible for regulating the temperature, not pressure. The heat exchanger facilitates the transfer of heat but does not play a direct role in pressure management within the boiler system. Hence, the safety valve's role as a pressure relief device makes it vital for ensuring the operational safety of the boiler.