Certified Facility Manager (CFM) Practice Exam

Which type of mixing valve prevents burns from hot water?

1. Pressure-reducing valve

2. Thermostatic mixing valve

3. Check valve

4. Ball valve

The correct answer is: Thermostatic mixing valve

A thermostatic mixing valve is designed to blend hot water with cold water to deliver water at a safe and consistent temperature. This prevents scalding or burns that can occur with water that exceeds certain temperatures. These valves automatically adjust the mix of hot and cold water according to pre-set temperatures, ensuring that the output is safe for use, particularly in settings like residential bathrooms or healthcare facilities where vulnerable individuals may be at risk of burns. Pressure-reducing valves primarily manage water pressure within a system, which does not inherently control or modify the temperature. Check valves are used to prevent backflow in plumbing systems, ensuring water flows in one direction, and are not involved in temperature control. Ball valves serve as on/off control for fluid flow but do not regulate temperature. Therefore, while all the other types of valves have specific functions within plumbing systems, only the thermostatic mixing valve is focused on preventing burns by controlling water temperature effectively.