Cross Connection Practice Exam

What is the purpose of the spring in the relief valve of a Reduced Pressure Principle Backflow Assembly?

1. To maintain constant pressure

2. To prevent backflow

3. To open the relief valve

4. To close the assembly

The correct answer is: To open the relief valve

The purpose of the spring in the relief valve of a Reduced Pressure Principle Backflow Assembly is to open the relief valve. In this type of assembly, the spring exerts a force that counteracts the pressure in the system. When the pressure downstream drops significantly below the pressure upstream, the spring allows the relief valve to open, thus providing a pathway to discharge water that may contain contaminants. This action is essential for the function of the backflow assembly, as it helps ensure that any backflow occurring due to pressure changes does not re-enter the potable water system, thereby protecting the water supply from contamination. The other choices relate to different functions of components in a backflow prevention system but do not specifically describe the role of the spring in the relief valve. For instance, maintaining constant pressure is typically the job of pressure regulators, while preventing backflow is the primary function of the overall assembly. Closing the assembly would not involve the spring’s action directly but rather would involve other mechanisms or components designed to stop water flow. Thus, focusing on the specific function of the spring clarifies its critical role in the operation of the relief valve.