Which component's submersion presents a cross-connection risk in backflow prevention devices?

• A. Pressure Gauge
• B. Test Cocks
• C. Backflow Preventer Body
• D. U-Bend

Answer: (B)

Test cocks are the small ports that provide access to the downstream side of a backflow preventer for testing. If these ports become submerged in contaminated or standing water, contaminants can enter through the test ports and be drawn back into the potable water system during pressure changes or testing. This creates a direct cross-connection path, bypassing the device’s protection. Keeping test cocks dry, capped, and protected prevents this unintended backflow. The other components aren’t direct access points for testing or submersion in the same way, so they don’t present the same cross-connection risk when submerged.