8" Reduced Pressure Detector Assembly with OS&Y. Series C500 Reduced Pressure Detector assembly provides protection to drinking water supplies from dangerous cross connections in accordance with national plumbing codes and water authority requirements for health-hazard non-potable service applications such as irrigation, fire line, or industrial processing. The Colt series is used to monitor unauthorized use of water from the fire protection system. The series include a flood sensor to detect excessive water discharges from the relief valve. The flood sensor relays a signal that triggers a multichannel alert (call, email, text) to notify personnel about potential flooding. The OS&Y model includes an option for an integrated supervisory switch on each gate valve.