Class 5 Boiler Practice Exam

What function do blow-off valves serve in a boiler system?

1. To release excess steam

2. To maintain water level

3. To drain the boiler

4. To prevent corrosion

The correct answer is: To drain the boiler

Blow-off valves serve the critical function of draining the boiler. They are designed to remove accumulated sediments, mud, and other impurities that settle at the bottom of the boiler during operation. Regularly draining the boiler helps maintain water quality and system efficiency, preventing issues such as scale formation that can adversely impact heat transfer and the overall operation of the boiler. The ability to drain the boiler means that the blow-off valve is instrumental in ensuring the longevity of the unit and reducing the risk of boiler failure. When impurities are not removed, they can lead to clogs and decrease the boiler's efficiency and safety. In this context, while blow-off valves can indirectly impact other aspects such as steam release and possibly corrosion by maintaining water quality, their primary function is specifically related to draining the boiler. This maintenance aspect is vital for the safe operation of boiler systems.