Turned water on to backflow, water was constantly discharging to drain. Isolated water and broke down backflow. Found 1st check fouled with debris, majority of it was copper pipe shavings. Cleaned both checks and put back together. Restored water and unit is working as should. Tested backflowflow. Unit passed. Location: fire Sprinkler room Use: Domestic Water Water Pressure: 70psi Make: Watts Model: 957 Serial number: YG-1232 Size: 2-1/2 inch 1st check: 7.0 2nd check: 5.0 Relief: 3.0