What is the function of a blow-off valve in a boiler?

The function of a blow-off valve in a boiler is primarily to remove sediment and sludge that collects at the bottom of the boiler. Over time, various impurities, minerals, and debris can accumulate within the water in the boiler, potentially leading to decreased efficiency and even damage to the boiler components. The blow-off valve facilitates this maintenance task by allowing operators to periodically drain a portion of the boiler water, thereby flushing out these deposits. This process is essential for maintaining water quality and ensuring the safe and efficient operation of the boiler.

While controlling pressure, releasing excess heat, and preventing water loss are important aspects of boiler operation, they are not the primary function of a blow-off valve. Instead, those aspects are managed by other components and control systems within the boiler setup. For instance, pressure control is typically managed by pressure relief valves or automatic control systems, making it clear that the blow-off valve is specifically designed for the removal of sediment and sludge.