A differential pressure gauge is used to test which types of backflow assemblies?

A differential pressure gauge is specifically designed to measure the pressure difference between two points in a system, making it particularly useful for testing backflow assemblies that require monitoring of pressure differentials to ensure they are functioning correctly. In the context of backflow prevention devices, the double-check valve assembly and reduced pressure zone (RPZ) assemblies both rely on maintaining specific pressure relationships to prevent backflow.

Double-check assemblies utilize two check valves to safeguard against backflow, and the pressure differential between the inlet and outlet sides must be monitored to ensure that no backflow occurs. Similarly, RPZ assemblies have a unique feature that includes a reduced pressure zone, which must be maintained to prevent any potential backflow of contaminated water. Testing these systems with a differential pressure gauge allows for the detection of any weaknesses or failures in the check valves or the system that may allow for backflow.

While atmospheric vacuum breakers are used to prevent backflow caused by siphoning, they do not operate based on pressure differentials in the same way and typically do not require a differential pressure gauge for testing. The same applies to other types of backflow preventers, which may have different testing requirements not related to pressure differentials. Therefore, the use of a differential pressure gauge is specifically relevant for