Get Steamy with the Class 5 Boiler Exam 2026 – Ignite Your Career Potential!

The function of a blowdown valve in a boiler is primarily to remove sediment and concentrate dissolved solids from the water. Over time, impurities and minerals can accumulate in the boiler water, which can lead to scale formation and reduced heat transfer efficiency. If these contaminants are not managed properly, they can negatively impact the boiler's performance and longevity.

When the blowdown valve is opened, a portion of the boiler water is expelled into the drainage system, taking with it the accumulated sediment and dissolved solids. This practice helps maintain the water quality within the boiler, ensuring effective operation and preventing potential issues such as foaming or carryover of water into the steam. Regularly managing blowdown also helps maintain safe operating conditions and prolongs the life of the boiler system.

The other options refer to functions that do not relate to the blowdown process. Increasing steam pressure, controlling steam temperature, and shutting off the fuel supply during emergencies are tasks managed by different components of the boiler system.