Minnesota Boiler License Practice Exam

What safety feature prevents backflow of water in a boiler?

1. Check valve

2. Pressure relief valve

3. Safety relief valve

4. Isolation valve

The correct answer is: Check valve

The check valve is a critical safety feature in a boiler system designed to prevent the backflow of water. Its primary function is to allow flow in only one direction, ensuring that water moves through the system without reversing. This is essential in maintaining the proper functioning of the boiler and safeguarding against potential damage that could occur if water were to flow backward. For instance, if there were a drop in pressure in the supply line, water could potentially flow back into the supply source, leading to contamination or even system failure. By employing a check valve, the integrity of the system is maintained, allowing for consistent operation and preventing any adverse effects from backflow. Other options, such as the pressure relief valve and safety relief valve, serve different purposes related to pressure control and safety, but they do not specifically address the prevention of backflow. The isolation valve is used to shut off the flow for maintenance or repairs rather than preventing backflow. Hence, the check valve is the appropriate choice for the function described in the question.