0206556 (Ames-Deringer) | 3 Inch | SS Double Check Detector Backflow Preventer Assembly | Colt | NRS Shutoffs | Tri-Link Checks | Less MeterThis Colt 3 Inch Double Check Detector Backflow Preventer Assembly is Designed to Prevent The Reverse Flow of Fire Protection Substances And Water of Non Potable Quality From Being Pumped or Siphoned Into The Potable Water Supply Due to Backsiphonage And or Backpressure in Accordance With National Plumbing Codes And Water Authority Requirements. It is Ideal For Protection at Cross Connections Identified as Non Health Hazards Such as on Fire Sprinkler