Forward flow testing is performed to verify the operation of which device?

• A. Hose valve
• B. Main drain valve
• C. Backflow prevention assembly
• D. Pressure regulator

Answer: (C)

Forward flow testing focuses on the backflow prevention assembly to confirm it allows normal forward flow without compromising its backflow protection. When demand appears on the system, water must pass through the device in the forward direction and the internal check valves should open properly while remaining capable of closing to prevent reverse flow. The test checks that the upstream check opens at the correct pressure and seals when flow ceases, and, in assemblies like RPZ, that the relief sequence functions and does not leak back toward the supply. This verifies the device will protect the water supply from contamination while not hindering normal operation of the standpipe or hose system. Other components, such as a hose valve, main drain valve, or a pressure regulator, perform different functions and are not the focus of forward flow testing for backflow protection.