Which component is NOT part of a double check assembly?

In the context of a double check assembly, understanding the primary components is crucial for recognizing its function and design. A double check assembly is a type of backflow prevention device designed to protect potable water supplies from contamination due to backflow.

The critical components of a double check assembly include two check valves, which are essential for controlling the flow of water and preventing backflow. Additionally, test cocks are included in the assembly to allow for pressure testing and maintenance of the device, ensuring its operational integrity. Shutoff valves are also part of this assembly as they enable isolation of the device during maintenance or testing.

However, a pressure relief valve is not a component of a double check assembly. While pressure relief valves are essential in other types of backflow prevention devices, such as reduced pressure zone assemblies, they are not present in the configuration of a double check assembly. This distinction is essential for understanding the specific functionality of backflow prevention systems and their various configurations.