What is considered the most important fitting on a boiler?

The safety valve is considered the most important fitting on a boiler because it serves a critical safety function by preventing excess pressure from building up within the system. Boilers operate under high pressure, and if too much pressure accumulates, it can lead to catastrophic failures, including explosions. The safety valve is designed to open automatically when the pressure reaches a predetermined threshold, allowing steam or water to escape and thereby relieving pressure in the boiler. This safety mechanism protects both the boiler and its operators, making it an essential component for safe operation.

The pressure gauge is important as it provides essential information about the operating conditions of the boiler, but it does not actively prevent hazardous situations. The blowoff valve is crucial for maintenance and cleaning purposes, while the feedwater valve controls the water entering the boiler but does not directly manage the pressure situation. Thus, the safety valve's role in pressure regulation and safety makes it the most vital fitting on a boiler.